Re: [Biofuel] Solar Concentrator & PV Modules

[Lugano Wilson]

hi Logan.      PV modules and solar concentrators are two different technologies and unfortunately, their individual energy capture principle is contradicting to each other. consequently, they can not be used at same application. PV modules need to absorb all the solar radiation so as to generate electricity through the module cells where as solar concentrators have to reflect all the solar radiation and direct it at a specific location (ie concentrated) for the purpose of heating a medium that can latter generate required energy. you therefore need to choose one for a specific application. however, when it comes to electricity the pv modules are good due to the fact that you can size them depending on your requirement starting with one module and increasing. concentrators for electricity is a large scale project - not so "modular".      LuganoLogan Vilas <[EMAIL PROTECTED]>
 wrote:  Would a standard PV module produce more when used with a Solar Concentratoror does it require a special PV module?Logan Vilas___Biofuel mailing listBiofuel@sustainablelists.orghttp://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.orgBiofuel at Journey to Forever:http://journeytoforever.org/biofuel.htmlSearch the combined Biofuel and Biofuels-biz list archives (50,000 messages):http://www.mail-archive.com/biofuel@sustainablelists.org/
	
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Re: [Biofuel] Solar Concentrator & PV Modules

[Joe Street]

Actually mirrors can be used to concentrate the light from a large area 
onto a small high efficiency solar cell.  It is being done.  This is one 
of the justifications for the cost of high efficiency cells but the 
extra cost of the concentrators and the lengths one has to go to to keep 
from overheating the PV module unfortunately outstrip the savings the 
idea hopes to offer.  Too bad but on the other hand if you are just 
fortunate to have access to heterojunction cells on the cheap then maybe 
you should go for it!  You will need a liquid cooled backing plate for 
the cells but if you are crafty you might be able to use the rejected 
heat somehow as well!

Joe

Lugano Wilson wrote:

> hi Logan.
>  
> PV modules and solar concentrators are two different technologies and 
> unfortunately, their individual energy capture principle is 
> contradicting to each other. consequently, they can not be used at same 
> application. PV modules need to absorb all the solar radiation so as to 
> generate electricity through the module cells where as solar 
> concentrators have to reflect all the solar radiation and direct it at a 
> specific location (ie concentrated) for the purpose of heating a medium 
> that can latter generate required energy. you therefore need to choose 
> one for a specific application. however, when it comes to electricity 
> the pv modules are good due to the fact that you can size them depending 
> on your requirement starting with one module and increasing. 
> concentrators for electricity is a large scale project - not so "modular".
>  
> Lugano
> 
> */Logan Vilas <[EMAIL PROTECTED]>/* wrote:
> 
> Would a standard PV module produce more when used with a Solar
> Concentrator
> or does it require a special PV module?
> 
> Logan Vilas
> 
> 
> ___
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> 
> Search the combined Biofuel and Biofuels-biz list archives (50,000
> messages):
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> 
> 
> 
> Yahoo! Mail goes everywhere you do. Get it on your phone 
> .
>  
> 
> 
> 
> 
> 
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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

Most of the highest efficiency PV cells do use concentrators.  These
are the 35% efficient super exotic ones that NREL and others are
working on.  Compared to 20% which is about the highest commercial
single sun efficiency right now.  In general the power produced by a
PV cell is linearly related to the energy input.  More sun = more
power.  So if you put 25 suns on it, you get 25 times the amount of
power from the same cell (assuming you don't change the spectral
composition of the l ight).  It's not quite linear, so I think you
actually get a tiny bit more power at higher concentrations than just
the concentration ratio would imply -- say 28 instead of 25. The
problem is that a typical crystalline silicon cell also decreased its
power about 0.5% for each degree celsius the temperature goes up.  So
if you increase the operating temperature of the cell from 60C
(typical for one sun) to 200C, you've just lost all the power you
gained by putting more light on it  Plus if you get too hot,
you'll damage it -- usually the encapsulating material degrades well
before the temperature at which the actual PV cell is damaged though.
The other thing is that concentrators require tracking the sun usually
(at least to achieve more than 2 or 3 times concentration.  This
introduces moving parts to the equation, and destroys one of the nice
features of PV.  If it's a big central power station where you can
hire a full time maintenance operator, then go ahead.  If for your own
house, regular PV is cheap enough that the simplicity of not having
moving parts will probably outweigh any advantage of trying to get
more from the same amount of silicon.

Zeke

On 5/12/06, Joe Street <[EMAIL PROTECTED]> wrote:
> Actually mirrors can be used to concentrate the light from a large area
> onto a small high efficiency solar cell.  It is being done.  This is one
> of the justifications for the cost of high efficiency cells but the
> extra cost of the concentrators and the lengths one has to go to to keep
> from overheating the PV module unfortunately outstrip the savings the
> idea hopes to offer.  Too bad but on the other hand if you are just
> fortunate to have access to heterojunction cells on the cheap then maybe
> you should go for it!  You will need a liquid cooled backing plate for
> the cells but if you are crafty you might be able to use the rejected
> heat somehow as well!
>
> Joe
>
> Lugano Wilson wrote:
>
> > hi Logan.
> >
> > PV modules and solar concentrators are two different technologies and
> > unfortunately, their individual energy capture principle is
> > contradicting to each other. consequently, they can not be used at same
> > application. PV modules need to absorb all the solar radiation so as to
> > generate electricity through the module cells where as solar
> > concentrators have to reflect all the solar radiation and direct it at a
> > specific location (ie concentrated) for the purpose of heating a medium
> > that can latter generate required energy. you therefore need to choose
> > one for a specific application. however, when it comes to electricity
> > the pv modules are good due to the fact that you can size them depending
> > on your requirement starting with one module and increasing.
> > concentrators for electricity is a large scale project - not so "modular".
> >
> > Lugano
> >
> > */Logan Vilas <[EMAIL PROTECTED]>/* wrote:
> >
> > Would a standard PV module produce more when used with a Solar
> > Concentrator
> > or does it require a special PV module?
> >
> > Logan Vilas
> >
> >
> > ___
> > Biofuel mailing list
> > Biofuel@sustainablelists.org
> > 
> > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org
> >
> > Biofuel at Journey to Forever:
> > http://journeytoforever.org/biofuel.html
> >
> > Search the combined Biofuel and Biofuels-biz list archives (50,000
> > messages):
> > http://www.mail-archive.com/biofuel@sustainablelists.org/
> >
> >
> > 
> > Yahoo! Mail goes everywhere you do. Get it on your phone
> > .
> >
> >
> >
> > 
> >
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> >
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> >
> > Search the combined Biofuel and Biofuels-biz list archives (50,000 
> > messages):
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> >
>
>
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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

Concentrators (heliostats) use tracking technology. The only difference is the half angle mechanism used in concentrators to reflect the light instead of keeping a surface normal to the Sun's rays.      Once tracking technology becomes cost competitive when compared to simply adding more PV modules (approx. 30% increase in energy conversion with 2 axis tracker), the technology will be commonplace and in some places inseparable. It's a little early to say for sure, that PV will work better with concentrated light but, I sure hope the "writing on the wall" is correct.     ...a biased opinion.     US #6,897,423Self-powered intermittent moving light tracking device and method Mike     Lugano Wilson <[EMAIL PROTECTED]>
 wrote:hi Logan.      PV modules and solar concentrators are two different technologies and unfortunately, their individual energy capture principle is contradicting to each other. consequently, they can not be used at same application. PV modules need to absorb all the solar radiation so as to generate electricity through the module cells where as solar concentrators have to reflect all the solar radiation and direct it at a specific location (ie concentrated) for the purpose of heating a medium that can latter generate required energy. you therefore need to choose one for a specific application. however, when it comes to electricity the pv modules are good due to the fact that you can size them depending on your requirement starting with one module and increasing. concentrators for electricity is a large scale project - not so
 "modular".      LuganoLogan Vilas <[EMAIL PROTECTED]> wrote:Would a standard PV module produce more when used with a Solar Concentratoror does it require a special PV module?Logan Vilas     [snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

Yes, you get get 30% more power from the same PV modules, but the
space requirements for a tracker can actually be higher than for 30%
more fixed PV.  Fixed PV can be mounted on a building, often on a
existing surface, thus essentially not taking up any room.  A tracker
(at least the current versions) require a large pole and room to turn.
 I've found that alot of people are okay with putting modules on their
roof that isn't doing anything else anyway, but fewer want something
in the backyard, or sticking up off the roof. Aesthetics are strange
drivers (I know of one case in which the national park service didn't
want a 2,000 sq foot PV array, because it would destroy the natural
beauty, but apparently the 250 car parking lot and droning diesel
generators didn't...).In higher density urban areas, finding the
required volumes of space in which to mount trackers would be even
harder, whereas every urban area has surfaces which receive sunlight.

On 5/12/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>
> Concentrators (heliostats) use tracking technology. The only difference is
> the half angle mechanism used in concentrators to reflect the light instead
> of keeping a surface normal to the Sun's rays.
>
> Once tracking technology becomes cost competitive when compared to simply
> adding more PV modules (approx. 30% increase in energy conversion with 2
> axis tracker), the technology will be commonplace and in some places
> inseparable. It's a little early to say for sure, that PV will work better
> with concentrated light but, I sure hope the "writing on the wall" is
> correct.
>
> ...a biased opinion.
>
> US #6,897,423
> Self-powered intermittent moving light tracking device and method
>
> Mike
>
>
> Lugano Wilson <[EMAIL PROTECTED]> wrote:
>
>
> hi Logan.
>
> PV modules and solar concentrators are two different technologies and
> unfortunately, their individual energy capture principle is contradicting to
> each other. consequently, they can not be used at same application. PV
> modules need to absorb all the solar radiation so as to generate electricity
> through the module cells where as solar concentrators have to reflect all
> the solar radiation and direct it at a specific location (ie concentrated)
> for the purpose of heating a medium that can latter generate required
> energy. you therefore need to choose one for a specific application.
> however, when it comes to electricity the pv modules are good due to the
> fact that you can size them depending on your requirement starting with one
> module and increasing. concentrators for electricity is a large scale
> project - not so "modular".
>
> Lugano
>
> Logan Vilas <[EMAIL PROTECTED]> wrote:
>
>
> Would a standard PV module produce more when used with a Solar Concentrator
> or does it require a special PV module?
>
> Logan Vilas
>
>
> [snip]
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> messages):
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>
>
>

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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

Hi Zeke,     Although "the space requirements for a tracker can actually be higher than 30%more", it doesn't have to be.      The "current versions" certainly do not need to be on a large pole (http://www.abc.net.au/newinventors/txt/s1487858.htm).     With all due respect, you're comments (intentionally or not) confine the discussion to schemes that actually do take 30% more space (i.e. large, common Gimbal arrangements).     As far as aesthetics are concerned, I agree that people in the US have a strange sense of what looks good on the landscape. As soon as the culture becomes more educated about energy and the environment, I hope that their sense of aesthetics will change too.     Have you ever driven through a large housing development and
 notice the number of satellite dishes?     Mike     Zeke Yewdall <[EMAIL PROTECTED]> wrote:  Yes, you get get 30% more power from the same PV modules, but thespace requirements for a tracker can actually be higher than for 30%more fixed PV. Fixed PV can be mounted on a building, often on aexisting surface, thus essentially not taking up any room. A tracker(at least the current versions) require a large pole and room to turn.I've found that alot of people are okay with putting modules on theirroof that isn't doing anything else anyway, but fewer want somethingin the backyard, or sticking up off the roof. Aesthetics are strangedrivers (I know of one case in which the national park service didn'twant a 2,000 sq foot PV array, because it would destroy the
 naturalbeauty, but apparently the 250 car parking lot and droning dieselgenerators didn't...). In higher density urban areas, finding therequired volumes of space in which to mount trackers would be evenharder, whereas every urban area has surfaces which receive sunlight.On 5/12/06, Michael Redler <[EMAIL PROTECTED]>wrote:>> Concentrators (heliostats) use tracking technology. The only difference is> the half angle mechanism used in concentrators to reflect the light instead> of keeping a surface normal to the Sun's rays.>> Once tracking technology becomes cost competitive when compared to simply> adding more PV modules (approx. 30% increase in energy conversion with 2> axis tracker), the technology will be commonplace and in some places> inseparable. It's a little early to say for sure, that PV will work better> with concentrated light but, I sure hope the "writing on the wall"
 is> correct.>> ...a biased opinion.>> US #6,897,423> Self-powered intermittent moving light tracking device and method>> Mike>>> Lugano Wilson <[EMAIL PROTECTED]>wrote:>>> hi Logan.>> PV modules and solar concentrators are two different technologies and> unfortunately, their individual energy capture principle is contradicting to> each other. consequently, they can not be used at same application. PV> modules need to absorb all the solar radiation so as to generate electricity> through the module cells where as solar concentrators have to reflect all> the solar radiation and direct it at a specific location (ie concentrated)> for the purpose of heating a medium that can latter generate required> energy. you therefore need to choose one for a specific application.> however, when it comes to electricity
 the pv modules are good due to the> fact that you can size them depending on your requirement starting with one> module and increasing. concentrators for electricity is a large scale> project - not so "modular".>> Lugano>> Logan Vilas <[EMAIL PROTECTED]>wrote:>>> Would a standard PV module produce more when used with a Solar Concentrator> or does it require a special PV module?>> Logan Vilas>>> [snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

By now, you may have noticed my resistance to "conventional wisdom" whenever someone gives negative feedback about a particular energy scheme. Here is an example.     The idea of concentrating light onto PV cells is a relatively new idea in some circles. What to do about waste heat is a natural progression in the discussion of such technology. But, why is it seen as such an obstacle - especially when schemes for harvesting waste heat are so abundant in energy related discussions?     You wrote: "...regular PV is cheap enough that the simplicity of not havingmoving parts will probably outweigh any advantage of trying to get more from the same amount of silicon."     The sweeping statements are getting old Zeke. Adding trackers become advantageous when you run out of roof. By the way PV that works on concentrated sunlight isn't so exotic and will probably become the PV of choice in a
 large percentage of applications. The large cost of concentrating PV is likely to be offset by an increase in power conversion requiring the use of heliostats, tracking technology and those pesky moving parts.     Mike Zeke Yewdall <[EMAIL PROTECTED]> wrote:Most of the highest efficiency PV cells do use concentrators. Theseare the 35% efficient super exotic ones that NREL and others areworking on. Compared to 20% which is about the highest commercialsingle sun efficiency right now. In general the power produced by aPV cell is linearly related to the energy input. More sun = morepower. So if you put 25 suns on it, you get 25 times the amount ofpower from the same cell (assuming you don't change the spectralcomposition of the l ight). It's not
 quite linear, so I think youactually get a tiny bit more power at higher concentrations than justthe concentration ratio would imply -- say 28 instead of 25. Theproblem is that a typical crystalline silicon cell also decreased itspower about 0.5% for each degree celsius the temperature goes up. Soif you increase the operating temperature of the cell from 60C(typical for one sun) to 200C, you've just lost all the power yougained by putting more light on it Plus if you get too hot,you'll damage it -- usually the encapsulating material degrades wellbefore the temperature at which the actual PV cell is damaged though.The other thing is that concentrators require tracking the sun usually(at least to achieve more than 2 or 3 times concentration. Thisintroduces moving parts to the equation, and destroys one of the nicefeatures of PV. If it's a big central power station where you canhire a full time maintenance operator,
 then go ahead. If for your ownhouse, regular PV is cheap enough that the simplicity of not havingmoving parts will probably outweigh any advantage of trying to getmore from the same amount of silicon.ZekeOn 5/12/06, Joe Street <[EMAIL PROTECTED]>wrote:> Actually mirrors can be used to concentrate the light from a large area> onto a small high efficiency solar cell. It is being done. This is one> of the justifications for the cost of high efficiency cells but the> extra cost of the concentrators and the lengths one has to go to to keep> from overheating the PV module unfortunately outstrip the savings the> idea hopes to offer. Too bad but on the other hand if you are just> fortunate to have access to heterojunction cells on the cheap then maybe> you should go for it! You will need a liquid cooled backing plate for> the cells but if you are crafty you might be able to use
 the rejected> heat somehow as well!>> Joe>> Lugano Wilson wrote:>> > hi Logan.> >> > PV modules and solar concentrators are two different technologies and> > unfortunately, their individual energy capture principle is> > contradicting to each other. consequently, they can not be used at same> > application. PV modules need to absorb all the solar radiation so as to> > generate electricity through the module cells where as solar> > concentrators have to reflect all the solar radiation and direct it at a> > specific location (ie concentrated) for the purpose of heating a medium> > that can latter generate required energy. you therefore need to choose> > one for a specific application. however, when it comes to electricity> > the pv modules are good due to the fact that you can size them depending> > on
 your requirement starting with one module and increasing.> > concentrators for electricity is a large scale project - not so "modular".> >> > Lugano> >> > */Logan Vilas <[EMAIL PROTECTED]>/* wrote:> >> > Would a standard PV module produce more when used with a Solar> > Concentrator> > or does it require a special PV module?> >> > Logan Vilas  [snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

I am speaking mostly from experience, from what I have seen work and
fail in the field, and what I can buy to install for my clients. The
reason I talk about trackers on large poles is because that is what is
commercially sold right now (at least in the US, europe is ahead of us
in many areas).  And the biggest reason I see for failed systems is
lack of maintenance (mostly batteries, but also anything that moves).
Also, the number of new innovative PV systems that I have seen come on
the market over the years, only to dissapear within another year...
We're still basically doing the same thing as PV was in the 70's, with
incremental improvements in efficiency and incremental cost decreases.
 I called the concrentrating PV exotic merely because I can't call up
one of 200 some suppliers and buy one that meets all current
electrical code, whereas I can with silicon PV modules.  Maybe another
breakthrough is coming, but in the mean time, alot of people will keep
using coal generated power because they are waiting for those
breakthroughs.  I would rather see working PV systems going in today,
even if they aren't all that high tech, rather than people thinking
they have to wait before solar energy can work for them -- and in the
mean time continuing to support coal and oil.   It's not that I want
to limit the new technology, but what I have seen is that the
layperson holds out the possibility of a paradigm shift in the
technology in the future as a reason to do absolutely nothing now.
And if I recall, the original question was about concentrating
sunlight on a normal old PV module -- which isn't the best idea --
they tried that at the carrizo solar plant in the early 80's, and a
few years later, a whole lot of used Mud-lams (because the encapsulant
turned varying shades of brown) flooded the market for off-grid use.

I do admit that this list's members are not your average layperson,
and most of us won't just use the news of new inventions as an excuse
for procrastinating, so I apologize for that.

Zeke


On 5/12/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>
> By now, you may have noticed my resistance to "conventional wisdom" whenever
> someone gives negative feedback about a particular energy scheme. Here is an
> example.
>
> The idea of concentrating light onto PV cells is a relatively new idea in
> some circles. What to do about waste heat is a natural progression in the
> discussion of such technology. But, why is it seen as such an obstacle -
> especially when schemes for harvesting waste heat are so abundant in energy
> related discussions?
>
> You wrote: "...regular PV is cheap enough that the simplicity of not having
>
> moving parts will probably outweigh any advantage of trying to get more from
> the same amount of silicon."
>
>
> The sweeping statements are getting old Zeke. Adding trackers become
> advantageous when you run out of roof. By the way PV that works on
> concentrated sunlight isn't so exotic and will probably become the PV of
> choice in a large percentage of applications. The large cost of
> concentrating PV is likely to be offset by an increase in power conversion
> requiring the use of heliostats, tracking technology and those pesky moving
> parts.
>
>
> Mike
>
> Zeke Yewdall <[EMAIL PROTECTED]> wrote:
>
> Most of the highest efficiency PV cells do use concentrators. These
> are the 35% efficient super exotic ones that NREL and others are
> working on. Compared to 20% which is about the highest commercial
> single sun efficiency right now. In general the power produced by a
> PV cell is linearly related to the energy input. More sun = more
> power. So if you put 25 suns on it, you get 25 times the amount of
> power from the same cell (assuming you don't change the spectral
> composition of the l ight). It's not quite linear, so I think you
> actually get a tiny bit more power at higher concentrations than just
> the concentration ratio would imply -- say 28 instead of 25. The
> problem is that a typical crystalline silicon cell also decreased its
> power about 0.5% for each degree celsius the temperature goes up. So
> if you increase the operating temperature of the cell from 60C
> (typical for one sun) to 200C, you've just lost all the power you
> gained by putting more light on it Plus if you get too hot,
> you'll damage it -- usually the encapsulating material degrades well
> before the temperature at which the actual PV cell is damaged though.
> The other thing is that concentrators require tracking the sun usually
> (at least to achieve more than 2 or 3 times concentration. This
> introduces moving parts to the equation, and destroys one of the nice
> features of PV. If it's a big central power station where you can
> hire a full time maintenance operator, then go ahead. If for your own
> house, regular PV is cheap enough that the simplicity of not having
> moving parts will probably outweigh any advantage of trying to get
> more from the same amount of silicon.
>
> Zeke
>
>

Re: [Biofuel] Solar Concentrator & PV Modules

[logan vilas]

I am working with the idea of building my own Concentrator with about 50 
times the mirror space then collector space. That Is why the question was 
asked in the first place I was wondering if placeing a 50watt solar panel at 
the focal point would increase the power output. I've read that it is more 
then 100% liner increase in power output when increasing the amount of light 
on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know it 
would need to be kept cool. due to the fact that they are only 20-30% 
efficent, but I could use the coolant to heat my biodiesel processor, then 
the hot water going into my home before a tankless heater. If I were to get 
a grid tied inverter It would suppliment my normal power useage and maby 
with netmetering it might come close to canceling out my power requirements 
alltogther. a simple temp sensor could be used so if the temp is over 150f 
in the coolant it will shut down and not collect the sun anymore. As for a 
solar tracker that is relative easy with very simple electronics. The setup 
to hold everything would be a simple build for most people who can make 
their own biodiesel processor. And If I base it off a 7 meter dish I can get 
those free. I just have to use the labor to remove it.

Logan Vilas
- Original Message - 
From: "Zeke Yewdall" <[EMAIL PROTECTED]>
To: 
Sent: Friday, May 12, 2006 3:59 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


>I am speaking mostly from experience, from what I have seen work and
> fail in the field, and what I can buy to install for my clients. The
> reason I talk about trackers on large poles is because that is what is
> commercially sold right now (at least in the US, europe is ahead of us
> in many areas).  And the biggest reason I see for failed systems is
> lack of maintenance (mostly batteries, but also anything that moves).
> Also, the number of new innovative PV systems that I have seen come on
> the market over the years, only to dissapear within another year...
> We're still basically doing the same thing as PV was in the 70's, with
> incremental improvements in efficiency and incremental cost decreases.
> I called the concrentrating PV exotic merely because I can't call up
> one of 200 some suppliers and buy one that meets all current
> electrical code, whereas I can with silicon PV modules.  Maybe another
> breakthrough is coming, but in the mean time, alot of people will keep
> using coal generated power because they are waiting for those
> breakthroughs.  I would rather see working PV systems going in today,
> even if they aren't all that high tech, rather than people thinking
> they have to wait before solar energy can work for them -- and in the
> mean time continuing to support coal and oil.   It's not that I want
> to limit the new technology, but what I have seen is that the
> layperson holds out the possibility of a paradigm shift in the
> technology in the future as a reason to do absolutely nothing now.
> And if I recall, the original question was about concentrating
> sunlight on a normal old PV module -- which isn't the best idea --
> they tried that at the carrizo solar plant in the early 80's, and a
> few years later, a whole lot of used Mud-lams (because the encapsulant
> turned varying shades of brown) flooded the market for off-grid use.
>
> I do admit that this list's members are not your average layperson,
> and most of us won't just use the news of new inventions as an excuse
> for procrastinating, so I apologize for that.
>
> Zeke
>
>
> On 5/12/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>>
>> By now, you may have noticed my resistance to "conventional wisdom" 
>> whenever
>> someone gives negative feedback about a particular energy scheme. Here is 
>> an
>> example.
>>
>> The idea of concentrating light onto PV cells is a relatively new idea in
>> some circles. What to do about waste heat is a natural progression in the
>> discussion of such technology. But, why is it seen as such an obstacle -
>> especially when schemes for harvesting waste heat are so abundant in 
>> energy
>> related discussions?
>>
>> You wrote: "...regular PV is cheap enough that the simplicity of not 
>> having
>>
>> moving parts will probably outweigh any advantage of trying to get more 
>> from
>> the same amount of silicon."
>>
>>
>> The sweeping statements are getting old Zeke. Adding trackers become
>> advantageous when you run out of roof. By the way PV that works on
>> concentrated sunlight isn't so exotic and will probably become the PV of
>> choice in a large percentage of applications. The large cost of
>> co

Re: [Biofuel] Solar Concentrator & PV Modules

[Mike Redler]

I would REALLY like to see the results of such a test.

Good luck!!

Mike

logan vilas wrote:
> I am working with the idea of building my own Concentrator with about 50 
> times the mirror space then collector space. That Is why the question was 
> asked in the first place I was wondering if placeing a 50watt solar panel at 
> the focal point would increase the power output. I've read that it is more 
> then 100% liner increase in power output when increasing the amount of light 
> on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know it 
> would need to be kept cool. due to the fact that they are only 20-30% 
> efficent, but I could use the coolant to heat my biodiesel processor, then 
> the hot water going into my home before a tankless heater. If I were to get 
> a grid tied inverter It would suppliment my normal power useage and maby 
> with netmetering it might come close to canceling out my power requirements 
> alltogther. a simple temp sensor could be used so if the temp is over 150f 
> in the coolant it will shut down and not collect the sun anymore. As for a 
> solar tracker that is relative easy with very simple electronics. The setup 
> to hold everything would be a simple build for most people who can make 
> their own biodiesel processor. And If I base it off a 7 meter dish I can get 
> those free. I just have to use the labor to remove it.
>
> Logan Vilas
> - Original Message - 
> From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, May 12, 2006 3:59 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>   
>> I am speaking mostly from experience, from what I have seen work and
>> fail in the field, and what I can buy to install for my clients. The
>> reason I talk about trackers on large poles is because that is what is
>> commercially sold right now (at least in the US, europe is ahead of us
>> in many areas).  And the biggest reason I see for failed systems is
>> lack of maintenance (mostly batteries, but also anything that moves).
>> Also, the number of new innovative PV systems that I have seen come on
>> the market over the years, only to dissapear within another year...
>> We're still basically doing the same thing as PV was in the 70's, with
>> incremental improvements in efficiency and incremental cost decreases.
>> I called the concrentrating PV exotic merely because I can't call up
>> one of 200 some suppliers and buy one that meets all current
>> electrical code, whereas I can with silicon PV modules.  Maybe another
>> breakthrough is coming, but in the mean time, alot of people will keep
>> using coal generated power because they are waiting for those
>> breakthroughs.  I would rather see working PV systems going in today,
>> even if they aren't all that high tech, rather than people thinking
>> they have to wait before solar energy can work for them -- and in the
>> mean time continuing to support coal and oil.   It's not that I want
>> to limit the new technology, but what I have seen is that the
>> layperson holds out the possibility of a paradigm shift in the
>> technology in the future as a reason to do absolutely nothing now.
>> And if I recall, the original question was about concentrating
>> sunlight on a normal old PV module -- which isn't the best idea --
>> they tried that at the carrizo solar plant in the early 80's, and a
>> few years later, a whole lot of used Mud-lams (because the encapsulant
>> turned varying shades of brown) flooded the market for off-grid use.
>>
>> I do admit that this list's members are not your average layperson,
>> and most of us won't just use the news of new inventions as an excuse
>> for procrastinating, so I apologize for that.
>>
>> Zeke
>>
>>
>> On 5/12/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>> 
>>> By now, you may have noticed my resistance to "conventional wisdom" 
>>> whenever
>>> someone gives negative feedback about a particular energy scheme. Here is 
>>> an
>>> example.
>>>
>>> The idea of concentrating light onto PV cells is a relatively new idea in
>>> some circles. What to do about waste heat is a natural progression in the
>>> discussion of such technology. But, why is it seen as such an obstacle -
>>> especially when schemes for harvesting waste heat are so abundant in 
>>> energy
>>> related discussions?
>>>
>>> You wrote: "...regular PV is cheap enough that the simplicity of not 
>>> having
>>>
>>> moving parts will pro

Re: [Biofuel] Solar Concentrator & PV Modules

[Ken Provost]

On May 12, 2006, at 1:59 PM, Zeke Yewdall wrote:.. the biggest reason I see for failed systems islack of maintenance (mostly batteries, but alsoanything that moves).I've got my well pump on three 50W modules, fixed.It's totally maintenance-free. I don't think I'll usetrackers for the main house power either. If you havepoles, there's usually azimuth and elevation bracketsthat can be adjusted at any time. You set them foryour latitude first -- if you want to adjust themseasonally or daily, it's easy. If not, it works fine inthe original position. Good for us lazy types :-)-K___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Jason & Katie]

in theory, if one could find a way to waterproof the back of a PV cell it 
could be used as the heat-side plate in this concentrator/boiler found at 
(or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could 
safely increase the power range of a smaller PV cell without too horrible of 
a heat loss. the problem is finding a sealing substance that wont melt or 
burn under these 1200*F temperatures.


- Original Message - 
From: "logan vilas" <[EMAIL PROTECTED]>
To: 
Sent: Friday, May 12, 2006 4:54 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


>I am working with the idea of building my own Concentrator with about 50
> times the mirror space then collector space. That Is why the question was
> asked in the first place I was wondering if placeing a 50watt solar panel 
> at
> the focal point would increase the power output. I've read that it is more
> then 100% liner increase in power output when increasing the amount of 
> light
> on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know 
> it
> would need to be kept cool. due to the fact that they are only 20-30%
> efficent, but I could use the coolant to heat my biodiesel processor, then
> the hot water going into my home before a tankless heater. If I were to 
> get
> a grid tied inverter It would suppliment my normal power useage and maby
> with netmetering it might come close to canceling out my power 
> requirements
> alltogther. a simple temp sensor could be used so if the temp is over 150f
> in the coolant it will shut down and not collect the sun anymore. As for a
> solar tracker that is relative easy with very simple electronics. The 
> setup
> to hold everything would be a simple build for most people who can make
> their own biodiesel processor. And If I base it off a 7 meter dish I can 
> get
> those free. I just have to use the labor to remove it.
>
> Logan Vilas
> - Original Message ----- 
> From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, May 12, 2006 3:59 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>>I am speaking mostly from experience, from what I have seen work and
>> fail in the field, and what I can buy to install for my clients. The
>> reason I talk about trackers on large poles is because that is what is
>> commercially sold right now (at least in the US, europe is ahead of us
>> in many areas).  And the biggest reason I see for failed systems is
>> lack of maintenance (mostly batteries, but also anything that moves).
>> Also, the number of new innovative PV systems that I have seen come on
>> the market over the years, only to dissapear within another year...
>> We're still basically doing the same thing as PV was in the 70's, with
>> incremental improvements in efficiency and incremental cost decreases.
>> I called the concrentrating PV exotic merely because I can't call up
>> one of 200 some suppliers and buy one that meets all current
>> electrical code, whereas I can with silicon PV modules.  Maybe another
>> breakthrough is coming, but in the mean time, alot of people will keep
>> using coal generated power because they are waiting for those
>> breakthroughs.  I would rather see working PV systems going in today,
>> even if they aren't all that high tech, rather than people thinking
>> they have to wait before solar energy can work for them -- and in the
>> mean time continuing to support coal and oil.   It's not that I want
>> to limit the new technology, but what I have seen is that the
>> layperson holds out the possibility of a paradigm shift in the
>> technology in the future as a reason to do absolutely nothing now.
>> And if I recall, the original question was about concentrating
>> sunlight on a normal old PV module -- which isn't the best idea --
>> they tried that at the carrizo solar plant in the early 80's, and a
>> few years later, a whole lot of used Mud-lams (because the encapsulant
>> turned varying shades of brown) flooded the market for off-grid use.
>>
>> I do admit that this list's members are not your average layperson,
>> and most of us won't just use the news of new inventions as an excuse
>> for procrastinating, so I apologize for that.
>>
>> Zeke
>>
>>
>> On 5/12/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>>>
>>> By now, you may have noticed my resistance to "conventional wisdom"
>>> whenever
>>> someone gives negative feedback about a particular energy scheme. Here 
>>> is
>>> an
>>> example.
>>>
>>> The idea of c

Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

This is exactly what I did my master's thesis on.  The concept works
pretty well from a theoretical perspective.  I was just investigating
using water cooling for non-concrentrating PV, but it would work even
better for concentrating PV.  You shouldn't really have to deal with
1200F, at least if you are talking about water, because the maximum
working temp for a water based fluid is probably about 400F or so??
(assuming antifreeze additives and increased pressure).  Depends on
how much pressure you are talking about I guess.

On 5/13/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
> in theory, if one could find a way to waterproof the back of a PV cell it
> could be used as the heat-side plate in this concentrator/boiler found at
> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
> safely increase the power range of a smaller PV cell without too horrible of
> a heat loss. the problem is finding a sealing substance that wont melt or
> burn under these 1200*F temperatures.
>
>
> - Original Message -
> From: "logan vilas" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, May 12, 2006 4:54 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
> >I am working with the idea of building my own Concentrator with about 50
> > times the mirror space then collector space. That Is why the question was
> > asked in the first place I was wondering if placeing a 50watt solar panel
> > at
> > the focal point would increase the power output. I've read that it is more
> > then 100% liner increase in power output when increasing the amount of
> > light
> > on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
> > it
> > would need to be kept cool. due to the fact that they are only 20-30%
> > efficent, but I could use the coolant to heat my biodiesel processor, then
> > the hot water going into my home before a tankless heater. If I were to
> > get
> > a grid tied inverter It would suppliment my normal power useage and maby
> > with netmetering it might come close to canceling out my power
> > requirements
> > alltogther. a simple temp sensor could be used so if the temp is over 150f
> > in the coolant it will shut down and not collect the sun anymore. As for a
> > solar tracker that is relative easy with very simple electronics. The
> > setup
> > to hold everything would be a simple build for most people who can make
> > their own biodiesel processor. And If I base it off a 7 meter dish I can
> > get
> > those free. I just have to use the labor to remove it.
> >
> > Logan Vilas
> > - Original Message -
> > From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> > To: 
> > Sent: Friday, May 12, 2006 3:59 PM
> > Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> >
> >
> >>I am speaking mostly from experience, from what I have seen work and
> >> fail in the field, and what I can buy to install for my clients. The
> >> reason I talk about trackers on large poles is because that is what is
> >> commercially sold right now (at least in the US, europe is ahead of us
> >> in many areas).  And the biggest reason I see for failed systems is
> >> lack of maintenance (mostly batteries, but also anything that moves).
> >> Also, the number of new innovative PV systems that I have seen come on
> >> the market over the years, only to dissapear within another year...
> >> We're still basically doing the same thing as PV was in the 70's, with
> >> incremental improvements in efficiency and incremental cost decreases.
> >> I called the concrentrating PV exotic merely because I can't call up
> >> one of 200 some suppliers and buy one that meets all current
> >> electrical code, whereas I can with silicon PV modules.  Maybe another
> >> breakthrough is coming, but in the mean time, alot of people will keep
> >> using coal generated power because they are waiting for those
> >> breakthroughs.  I would rather see working PV systems going in today,
> >> even if they aren't all that high tech, rather than people thinking
> >> they have to wait before solar energy can work for them -- and in the
> >> mean time continuing to support coal and oil.   It's not that I want
> >> to limit the new technology, but what I have seen is that the
> >> layperson holds out the possibility of a paradigm shift in the
> >> technology in the future as a reason to do absolutely nothing now.
> >> And if I recall, the original question was about concentrating
> >> sunlight 

Re: [Biofuel] Solar Concentrator & PV Modules

[Hakan Falk]

Zeke,

Thermal solar panels can reach surface temperatures around 400
degree Celsius, but with pump or thermal driven circulation the water
temperatures will not reach boiling temperature and open system can
be used. I have such a system on my roof. Generally the efficiency
is around 35%. The normal PV cells have 8 to 12% efficiency and
the new high efficient ones around 34% efficiency, need cooling
in concentrator applications. If the concentrator is not too efficient,
they can be mounted on an air cooling device, similar to what is used
for electronic components, otherwise they must have liquid cooling.

Design criteria for thermal solar panels was researched by Spanish
and Swedish Universities in Almeria, Spain, in 1960's. This was used
by a Swedish company, that now deliver 70% of the world market for
commercial thermal solar elements. They are delivered in rolls, cut to
size and the space for the liquid is then expanded with air pressure.

This is my understanding of the quite interesting current technological
situation. Since you did your master on solar panels, it would be very
interesting to get your view on where this is moving and perspective on
future possibilities.

Hakan


At 00:29 14/05/2006, you wrote:
>This is exactly what I did my master's thesis on.  The concept works
>pretty well from a theoretical perspective.  I was just investigating
>using water cooling for non-concrentrating PV, but it would work even
>better for concentrating PV.  You shouldn't really have to deal with
>1200F, at least if you are talking about water, because the maximum
>working temp for a water based fluid is probably about 400F or so??
>(assuming antifreeze additives and increased pressure).  Depends on
>how much pressure you are talking about I guess.
>
>On 5/13/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
> > in theory, if one could find a way to waterproof the back of a PV cell it
> > could be used as the heat-side plate in this concentrator/boiler found at
> > (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
> > safely increase the power range of a smaller PV cell without too 
> horrible of
> > a heat loss. the problem is finding a sealing substance that wont melt or
> > burn under these 1200*F temperatures.
> >
> >
> > - Original Message -----
> > From: "logan vilas" <[EMAIL PROTECTED]>
> > To: 
> > Sent: Friday, May 12, 2006 4:54 PM
> > Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> >
> >
> > >I am working with the idea of building my own Concentrator with about 50
> > > times the mirror space then collector space. That Is why the question was
> > > asked in the first place I was wondering if placeing a 50watt solar panel
> > > at
> > > the focal point would increase the power output. I've read that 
> it is more
> > > then 100% liner increase in power output when increasing the amount of
> > > light
> > > on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
> > > it
> > > would need to be kept cool. due to the fact that they are only 20-30%
> > > efficent, but I could use the coolant to heat my biodiesel 
> processor, then
> > > the hot water going into my home before a tankless heater. If I were to
> > > get
> > > a grid tied inverter It would suppliment my normal power useage and maby
> > > with netmetering it might come close to canceling out my power
> > > requirements
> > > alltogther. a simple temp sensor could be used so if the temp 
> is over 150f
> > > in the coolant it will shut down and not collect the sun 
> anymore. As for a
> > > solar tracker that is relative easy with very simple electronics. The
> > > setup
> > > to hold everything would be a simple build for most people who can make
> > > their own biodiesel processor. And If I base it off a 7 meter dish I can
> > > get
> > > those free. I just have to use the labor to remove it.
> > >
> > > Logan Vilas
> > > - Original Message -
> > > From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> > > To: 
> > > Sent: Friday, May 12, 2006 3:59 PM
> > > Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> > >
> > >
> > >>I am speaking mostly from experience, from what I have seen work and
> > >> fail in the field, and what I can buy to install for my clients. The
> > >> reason I talk about trackers on large poles is because that is what is
> > >> commercially sold right now (at least in the US, europe is ahead of us
> > >> in many area

Re: [Biofuel] Solar Concentrator & PV Modules

[Logan Vilas]

The main concern would be thermal transfer rates of the materials that the
cell is made out of and max temp the cell can handle. I know PV are made
from silicone, but is there any more depective terms for the material? For
example all Iron is not steel and every version of it has different thermal
transfer rates. What is the maximum working temp of PV modules? From Those
two things I can calculate the maximum amount of concentration that should
work. Also approximately how large is a 50watt panel?

I can pick a PV module then based on size and material thermal transfer I
can calculate the thermal transfer it would have in BTUs. I would then
divide by 3.4 and that's the number of watts it can have aimed at it.
There's approximately 1000watts per square meter energy from the sun. The
mirrors are about 92% reflective and I would figure there it going to be
about 10% loss to heating the air between the PV and the mirrors. 82.8
percent of the energy will be transferred to the PV. That's 828watts per
square meter of mirrors. Divide the thermal transfer by 828 and that's the
max concentration that can be focused at that cell to keep it at the same
temp as the input temp of the coolant you are using. 

The overall design should be engineered to keep the cell within working temp
limits without loosing much of the power gain, so under 200F (I'm guessing),
while being able to dissipate 100% of the heat that is concentrated. It
would need to dissipate all the heat because of the chance that no
electricity will be used and all the energy will become heat. When 20-30% of
the energy is being turned into electricity then the cell temp will remain
an equal percentage lower. At these temps it could be done with water and no
additives, but a closed system with relief valve would be best otherwise the
water would evaporate. 

I am thinking a closed loop system of filtered and dewatered UVO. I have
firefighting material called fire blockade that can be added at 1% mixture
and that will ensure the oil is nonflamiable. That would cause the fluid to
not boil off or spontaneously combust.

Logan Vilas

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Zeke Yewdall
Sent: Saturday, May 13, 2006 5:30 PM
To: Biofuel@sustainablelists.org
Subject: Re: [Biofuel] Solar Concentrator & PV Modules

This is exactly what I did my master's thesis on.  The concept works
pretty well from a theoretical perspective.  I was just investigating
using water cooling for non-concrentrating PV, but it would work even
better for concentrating PV.  You shouldn't really have to deal with
1200F, at least if you are talking about water, because the maximum
working temp for a water based fluid is probably about 400F or so??
(assuming antifreeze additives and increased pressure).  Depends on
how much pressure you are talking about I guess.

On 5/13/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
> in theory, if one could find a way to waterproof the back of a PV cell it
> could be used as the heat-side plate in this concentrator/boiler found at
> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
> safely increase the power range of a smaller PV cell without too horrible
of
> a heat loss. the problem is finding a sealing substance that wont melt or
> burn under these 1200*F temperatures.
>
>
> - Original Message -
> From: "logan vilas" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, May 12, 2006 4:54 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
> >I am working with the idea of building my own Concentrator with about 50
> > times the mirror space then collector space. That Is why the question
was
> > asked in the first place I was wondering if placeing a 50watt solar
panel
> > at
> > the focal point would increase the power output. I've read that it is
more
> > then 100% liner increase in power output when increasing the amount of
> > light
> > on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
> > it
> > would need to be kept cool. due to the fact that they are only 20-30%
> > efficent, but I could use the coolant to heat my biodiesel processor,
then
> > the hot water going into my home before a tankless heater. If I were to
> > get
> > a grid tied inverter It would suppliment my normal power useage and maby
> > with netmetering it might come close to canceling out my power
> > requirements
> > alltogther. a simple temp sensor could be used so if the temp is over
150f
> > in the coolant it will shut down and not collect the sun anymore. As for
a
> > solar tracker that is relative easy with very simple electronics. The
> > setup
> > to hold everything would be a simple build for most people who can make
> > their ow

Re: [Biofuel] Solar Concentrator & PV Modules

[Kirk McLoren]

silicon semiconductors are not the material of choice for concentrating collectors.Gallium arsenide stand much higher temps.     regular solar panels can take probably a concentration of 3 but output voltage drops as temperature rises.  Discoloration/lack of transparency can occur as well. A few years back "mud" solar panels were offered at a discount. They were removed from service in a concentrator-tracker(Carrizo). The cells were dark brown as a result of degradation of an adhesive used to bond the cells to a cover glass. I don't know if recent panels are built the same way but you need to know this before running them with more light. I assume uv was the culprit. Too bad no one has a mirror that just reflects the wavelengths the silicon uses.     Also concentrators destroy things if they stagnate.     Kirk  Logan Vilas
 <[EMAIL PROTECTED]> wrote:  The main concern would be thermal transfer rates of the materials that thecell is made out of and max temp the cell can handle. I know PV are madefrom silicone, but is there any more depective terms for the material? Forexample all Iron is not steel and every version of it has different thermaltransfer rates. What is the maximum working temp of PV modules? From Thosetwo things I can calculate the maximum amount of concentration that shouldwork. Also approximately how large is a 50watt panel?I can pick a PV module then based on size and material thermal transfer Ican calculate the thermal transfer it would have in BTUs. I would thendivide by 3.4 and that's the number of watts it can have aimed at it.There's approximately 1000watts per square meter energy from the sun. Themirrors
 are about 92% reflective and I would figure there it going to beabout 10% loss to heating the air between the PV and the mirrors. 82.8percent of the energy will be transferred to the PV. That's 828watts persquare meter of mirrors. Divide the thermal transfer by 828 and that's themax concentration that can be focused at that cell to keep it at the sametemp as the input temp of the coolant you are using. The overall design should be engineered to keep the cell within working templimits without loosing much of the power gain, so under 200F (I'm guessing),while being able to dissipate 100% of the heat that is concentrated. Itwould need to dissipate all the heat because of the chance that noelectricity will be used and all the energy will become heat. When 20-30% ofthe energy is being turned into electricity then the cell temp will remainan equal percentage lower. At these temps it could be done with water and noadditives,
 but a closed system with relief valve would be best otherwise thewater would evaporate. I am thinking a closed loop system of filtered and dewatered UVO. I havefirefighting material called fire blockade that can be added at 1% mixtureand that will ensure the oil is nonflamiable. That would cause the fluid tonot boil off or spontaneously combust.Logan Vilas-Original Message-From: [EMAIL PROTECTED][mailto:[EMAIL PROTECTED] On Behalf Of Zeke YewdallSent: Saturday, May 13, 2006 5:30 PMTo: Biofuel@sustainablelists.orgSubject: Re: [Biofuel] Solar Concentrator & PV ModulesThis is exactly what I did my master's thesis on. The concept workspretty well from a theoretical perspective. I was just investigatingusing water cooling for non-concrentrating PV, but it would work evenbetter for concentrating PV. You shouldn't really have to deal with1200F, at
 least if you are talking about water, because the maximumworking temp for a water based fluid is probably about 400F or so??(assuming antifreeze additives and increased pressure). Depends onhow much pressure you are talking about I guess.On 5/13/06, Jason & Katie <[EMAIL PROTECTED]>wrote:> in theory, if one could find a way to waterproof the back of a PV cell it> could be used as the heat-side plate in this concentrator/boiler found at> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could> safely increase the power range of a smaller PV cell without too horribleof> a heat loss. the problem is finding a sealing substance that wont melt or> burn under these 1200*F temperatures.>>> - Original Message -----> From: "logan vilas" <[EMAIL PROTECTED]>> To: > Sent: Friday, May 12, 2006 4:54 PM> Subject: Re:
 [Biofuel] Solar Concentrator & PV Modules>>> >I am working with the idea of building my own Concentrator with about 50> > times the mirror space then collector space. That Is why the questionwas> > asked in the first place I was wondering if placeing a 50watt solarpanel> > at> > the focal point would increase the power output. I've read that it ismore> > then 100% liner increase in power output when increasing the amount of> > light> > on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know> > it&

Re: [Biofuel] Solar Concentrator & PV Modules

[Jason& Katie]

ok i might be behind the times,but if an aluminum heat sink, similar to a 
processor cooler was attatched to the wet side of the pv cell and immersed 
into the coolant fluid would it lower the surface temp of the pv cell even 
further?
- Original Message - 
From: "Hakan Falk" <[EMAIL PROTECTED]>
To: 
Sent: Saturday, May 13, 2006 6:35 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


>
> Zeke,
>
> Thermal solar panels can reach surface temperatures around 400
> degree Celsius, but with pump or thermal driven circulation the water
> temperatures will not reach boiling temperature and open system can
> be used. I have such a system on my roof. Generally the efficiency
> is around 35%. The normal PV cells have 8 to 12% efficiency and
> the new high efficient ones around 34% efficiency, need cooling
> in concentrator applications. If the concentrator is not too efficient,
> they can be mounted on an air cooling device, similar to what is used
> for electronic components, otherwise they must have liquid cooling.
>
> Design criteria for thermal solar panels was researched by Spanish
> and Swedish Universities in Almeria, Spain, in 1960's. This was used
> by a Swedish company, that now deliver 70% of the world market for
> commercial thermal solar elements. They are delivered in rolls, cut to
> size and the space for the liquid is then expanded with air pressure.
>
> This is my understanding of the quite interesting current technological
> situation. Since you did your master on solar panels, it would be very
> interesting to get your view on where this is moving and perspective on
> future possibilities.
>
> Hakan
>
>
> At 00:29 14/05/2006, you wrote:
>>This is exactly what I did my master's thesis on.  The concept works
>>pretty well from a theoretical perspective.  I was just investigating
>>using water cooling for non-concrentrating PV, but it would work even
>>better for concentrating PV.  You shouldn't really have to deal with
>>1200F, at least if you are talking about water, because the maximum
>>working temp for a water based fluid is probably about 400F or so??
>>(assuming antifreeze additives and increased pressure).  Depends on
>>how much pressure you are talking about I guess.
>>
>>On 5/13/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
>> > in theory, if one could find a way to waterproof the back of a PV cell 
>> > it
>> > could be used as the heat-side plate in this concentrator/boiler found 
>> > at
>> > (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
>> > safely increase the power range of a smaller PV cell without too
>> horrible of
>> > a heat loss. the problem is finding a sealing substance that wont melt 
>> > or
>> > burn under these 1200*F temperatures.
>> >
>> >
>> > - Original Message -
>> > From: "logan vilas" <[EMAIL PROTECTED]>
>> > To: 
>> > Sent: Friday, May 12, 2006 4:54 PM
>> > Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>> >
>> >
>> > >I am working with the idea of building my own Concentrator with about 
>> > >50
>> > > times the mirror space then collector space. That Is why the question 
>> > > was
>> > > asked in the first place I was wondering if placeing a 50watt solar 
>> > > panel
>> > > at
>> > > the focal point would increase the power output. I've read that
>> it is more
>> > > then 100% liner increase in power output when increasing the amount 
>> > > of
>> > > light
>> > > on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I 
>> > > know
>> > > it
>> > > would need to be kept cool. due to the fact that they are only 20-30%
>> > > efficent, but I could use the coolant to heat my biodiesel
>> processor, then
>> > > the hot water going into my home before a tankless heater. If I were 
>> > > to
>> > > get
>> > > a grid tied inverter It would suppliment my normal power useage and 
>> > > maby
>> > > with netmetering it might come close to canceling out my power
>> > > requirements
>> > > alltogther. a simple temp sensor could be used so if the temp
>> is over 150f
>> > > in the coolant it will shut down and not collect the sun
>> anymore. As for a
>> > > solar tracker that is relative easy with very simple electronics. The
>> > > setup
>> > > to hold everything would be 

Re: [Biofuel] Solar Concentrator & PV Modules

[Joe Street]

Silicon is quite fragile especially the thin polysilicon material used 
in cells.  You are right but any water pressure would break the cells. 
You need to bond them onto a heat conducting back plate like copper or 
aluminum with a heat conducting cement.  Aso the back is an electrical 
contact so you need isolation there.

Joe

Jason & Katie wrote:

> in theory, if one could find a way to waterproof the back of a PV cell it 
> could be used as the heat-side plate in this concentrator/boiler found at 
> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could 
> safely increase the power range of a smaller PV cell without too horrible of 
> a heat loss. the problem is finding a sealing substance that wont melt or 
> burn under these 1200*F temperatures.
> 
> 
> - Original Message - 
> From: "logan vilas" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, May 12, 2006 4:54 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> 
> 
> 
>>I am working with the idea of building my own Concentrator with about 50
>>times the mirror space then collector space. That Is why the question was
>>asked in the first place I was wondering if placeing a 50watt solar panel 
>>at
>>the focal point would increase the power output. I've read that it is more
>>then 100% liner increase in power output when increasing the amount of 
>>light
>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know 
>>it
>>would need to be kept cool. due to the fact that they are only 20-30%
>>efficent, but I could use the coolant to heat my biodiesel processor, then
>>the hot water going into my home before a tankless heater. If I were to 
>>get
>>a grid tied inverter It would suppliment my normal power useage and maby
>>with netmetering it might come close to canceling out my power 
>>requirements
>>alltogther. a simple temp sensor could be used so if the temp is over 150f
>>in the coolant it will shut down and not collect the sun anymore. As for a
>>solar tracker that is relative easy with very simple electronics. The 
>>setup
>>to hold everything would be a simple build for most people who can make
>>their own biodiesel processor. And If I base it off a 7 meter dish I can 
>>get
>>those free. I just have to use the labor to remove it.
>>
>>Logan Vilas
>>- Original Message - 
>>From: "Zeke Yewdall" <[EMAIL PROTECTED]>
>>To: 
>>Sent: Friday, May 12, 2006 3:59 PM
>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>
>>
>>
>>>I am speaking mostly from experience, from what I have seen work and
>>>fail in the field, and what I can buy to install for my clients. The
>>>reason I talk about trackers on large poles is because that is what is
>>>commercially sold right now (at least in the US, europe is ahead of us
>>>in many areas).  And the biggest reason I see for failed systems is
>>>lack of maintenance (mostly batteries, but also anything that moves).
>>>Also, the number of new innovative PV systems that I have seen come on
>>>the market over the years, only to dissapear within another year...
>>>We're still basically doing the same thing as PV was in the 70's, with
>>>incremental improvements in efficiency and incremental cost decreases.
>>>I called the concrentrating PV exotic merely because I can't call up
>>>one of 200 some suppliers and buy one that meets all current
>>>electrical code, whereas I can with silicon PV modules.  Maybe another
>>>breakthrough is coming, but in the mean time, alot of people will keep
>>>using coal generated power because they are waiting for those
>>>breakthroughs.  I would rather see working PV systems going in today,
>>>even if they aren't all that high tech, rather than people thinking
>>>they have to wait before solar energy can work for them -- and in the
>>>mean time continuing to support coal and oil.   It's not that I want
>>>to limit the new technology, but what I have seen is that the
>>>layperson holds out the possibility of a paradigm shift in the
>>>technology in the future as a reason to do absolutely nothing now.
>>>And if I recall, the original question was about concentrating
>>>sunlight on a normal old PV module -- which isn't the best idea --
>>>they tried that at the carrizo solar plant in the early 80's, and a
>>>few years later, a whole lot of used Mud-lams (because the encapsulant
>>>turned varying shades of brown) flooded the market for off-grid use.
>>>
>>

Re: [Biofuel] Solar Concentrator & PV Modules

[Chip Mefford]

Zeke Yewdall wrote:
> This is exactly what I did my master's thesis on.  The concept works
> pretty well from a theoretical perspective.  I was just investigating
> using water cooling for non-concrentrating PV, but it would work even
> better for concentrating PV.  You shouldn't really have to deal with
> 1200F, at least if you are talking about water, because the maximum
> working temp for a water based fluid is probably about 400F or so??
> (assuming antifreeze additives and increased pressure).  Depends on
> how much pressure you are talking about I guess.
> 

l was thinking of kludging up water jackets for PV panels, to feed
the INFLOW for a small evacuated tube solar heater, preheating the
inflow by 'cooling' the PVs.

Do you think this makes sense?

___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

This is basically what I did.  kludging would be the word for it, as
about once a week it would have a catestrophic leak and I'd have to
rebuild it.   Worked okay to get research data, but obviuosly not long
term  I found that preheating water for domestic hot water (which
could have final heating done either by real solar thermal collectors,
or gas/electric/etc) seemed to be the best.  Try to get it too hot and
the efficiency dropped way off (I had water tubes touching the back of
the PV module, but no front glazing), plus it didn't cool the PV cells
enough to help with electrical efficiency much either.  The trick is
to size the storage tank and PV area with the daily draw to still get
the cooling effect and not stagnate the tank.   I suppose with a
different collector design you could obtain higher temperatures, and
still probably not damage the PV module (unless the circulation loop
stagnated, then I'm not sure), but I was going more for cooling the
PV, and seeing the collected thermal energy could be useful, rather
than having high quality thermal energy as the primary goal.  Given
that typical solar thermal DHW system here in the US don't achieve
100% solar fraction anyway, I figured that preheat was a decent way to
go.  If you wanted to go for 100% solar fraction (which is what we
should be doing long term) cascading it with a higher temp solar
thermal collector might be alot better.

On 5/15/06, Chip Mefford <[EMAIL PROTECTED]> wrote:
> Zeke Yewdall wrote:
> > This is exactly what I did my master's thesis on.  The concept works
> > pretty well from a theoretical perspective.  I was just investigating
> > using water cooling for non-concrentrating PV, but it would work even
> > better for concentrating PV.  You shouldn't really have to deal with
> > 1200F, at least if you are talking about water, because the maximum
> > working temp for a water based fluid is probably about 400F or so??
> > (assuming antifreeze additives and increased pressure).  Depends on
> > how much pressure you are talking about I guess.
> >
>
> l was thinking of kludging up water jackets for PV panels, to feed
> the INFLOW for a small evacuated tube solar heater, preheating the
> inflow by 'cooling' the PVs.
>
> Do you think this makes sense?
>
> ___
> Biofuel mailing list
> Biofuel@sustainablelists.org
> http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org
>
> Biofuel at Journey to Forever:
> http://journeytoforever.org/biofuel.html
>
> Search the combined Biofuel and Biofuels-biz list archives (50,000 messages):
> http://www.mail-archive.com/biofuel@sustainablelists.org/
>
>

___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Jason & Katie]

aha, this is where i find a new idea.

the dielectric heat grease used between processors and heat sinks /should/ 
work to electrically insulate the cell from the water pack (not jackets, a 
flat sleeve covering the back with circulated coolant completely filling it) 
while conducting heat into the cooling vanes in the water pack, eliminating 
the risk of breakage, just as you say. the goop isnt exactly cheap, but it 
works rather effectively on high temp applications.

- Original Message - 
From: "Joe Street" <[EMAIL PROTECTED]>
To: 
Sent: Monday, May 15, 2006 9:26 AM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


> Silicon is quite fragile especially the thin polysilicon material used
> in cells.  You are right but any water pressure would break the cells.
> You need to bond them onto a heat conducting back plate like copper or
> aluminum with a heat conducting cement.  Aso the back is an electrical
> contact so you need isolation there.
>
> Joe
>
> Jason & Katie wrote:
>
>> in theory, if one could find a way to waterproof the back of a PV cell it
>> could be used as the heat-side plate in this concentrator/boiler found at
>> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
>> safely increase the power range of a smaller PV cell without too horrible 
>> of
>> a heat loss. the problem is finding a sealing substance that wont melt or
>> burn under these 1200*F temperatures.
>>
>>
>> - Original Message - 
>> From: "logan vilas" <[EMAIL PROTECTED]>
>> To: 
>> Sent: Friday, May 12, 2006 4:54 PM
>> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>
>>
>>
>>>I am working with the idea of building my own Concentrator with about 50
>>>times the mirror space then collector space. That Is why the question was
>>>asked in the first place I was wondering if placeing a 50watt solar panel
>>>at
>>>the focal point would increase the power output. I've read that it is 
>>>more
>>>then 100% liner increase in power output when increasing the amount of
>>>light
>>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
>>>it
>>>would need to be kept cool. due to the fact that they are only 20-30%
>>>efficent, but I could use the coolant to heat my biodiesel processor, 
>>>then
>>>the hot water going into my home before a tankless heater. If I were to
>>>get
>>>a grid tied inverter It would suppliment my normal power useage and maby
>>>with netmetering it might come close to canceling out my power
>>>requirements
>>>alltogther. a simple temp sensor could be used so if the temp is over 
>>>150f
>>>in the coolant it will shut down and not collect the sun anymore. As for 
>>>a
>>>solar tracker that is relative easy with very simple electronics. The
>>>setup
>>>to hold everything would be a simple build for most people who can make
>>>their own biodiesel processor. And If I base it off a 7 meter dish I can
>>>get
>>>those free. I just have to use the labor to remove it.
>>>
>>>Logan Vilas
>>>- Original Message - 
>>>From: "Zeke Yewdall" <[EMAIL PROTECTED]>
>>>To: 
>>>Sent: Friday, May 12, 2006 3:59 PM
>>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>>
>>>
>>>
>>>>I am speaking mostly from experience, from what I have seen work and
>>>>fail in the field, and what I can buy to install for my clients. The
>>>>reason I talk about trackers on large poles is because that is what is
>>>>commercially sold right now (at least in the US, europe is ahead of us
>>>>in many areas).  And the biggest reason I see for failed systems is
>>>>lack of maintenance (mostly batteries, but also anything that moves).
>>>>Also, the number of new innovative PV systems that I have seen come on
>>>>the market over the years, only to dissapear within another year...
>>>>We're still basically doing the same thing as PV was in the 70's, with
>>>>incremental improvements in efficiency and incremental cost decreases.
>>>>I called the concrentrating PV exotic merely because I can't call up
>>>>one of 200 some suppliers and buy one that meets all current
>>>>electrical code, whereas I can with silicon PV modules.  Maybe another
>>>>breakthrough is coming, but in the mean time, alot of people will keep
>>>>using coal generated power because they are 

Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

Google Richard Komp.  His book is called something like "practical
photovoltaics".  In the back of it, he's got a design for a
concentrating PV/thermal collectors.  I haven't looked at it for a
while, but if I recall, he soldered a copper plate to a copper pipe,
then glued the PV cells to the copper plate with silicon glue, maybe
with a piece of plastic in between to make sure it didn't short out???
 Can't vouch that I remember the details right, but that's what I
recall.  Then a semi-parabolic trough reflector to concentrate about 3
or 4 suns on it.

On 5/15/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
> aha, this is where i find a new idea.
>
> the dielectric heat grease used between processors and heat sinks /should/
> work to electrically insulate the cell from the water pack (not jackets, a
> flat sleeve covering the back with circulated coolant completely filling it)
> while conducting heat into the cooling vanes in the water pack, eliminating
> the risk of breakage, just as you say. the goop isnt exactly cheap, but it
> works rather effectively on high temp applications.
>
> - Original Message -
> From: "Joe Street" <[EMAIL PROTECTED]>
> To: 
> Sent: Monday, May 15, 2006 9:26 AM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
> > Silicon is quite fragile especially the thin polysilicon material used
> > in cells.  You are right but any water pressure would break the cells.
> > You need to bond them onto a heat conducting back plate like copper or
> > aluminum with a heat conducting cement.  Aso the back is an electrical
> > contact so you need isolation there.
> >
> > Joe
> >
> > Jason & Katie wrote:
> >
> >> in theory, if one could find a way to waterproof the back of a PV cell it
> >> could be used as the heat-side plate in this concentrator/boiler found at
> >> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
> >> safely increase the power range of a smaller PV cell without too horrible
> >> of
> >> a heat loss. the problem is finding a sealing substance that wont melt or
> >> burn under these 1200*F temperatures.
> >>
> >>
> >> - Original Message -
> >> From: "logan vilas" <[EMAIL PROTECTED]>
> >> To: 
> >> Sent: Friday, May 12, 2006 4:54 PM
> >> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> >>
> >>
> >>
> >>>I am working with the idea of building my own Concentrator with about 50
> >>>times the mirror space then collector space. That Is why the question was
> >>>asked in the first place I was wondering if placeing a 50watt solar panel
> >>>at
> >>>the focal point would increase the power output. I've read that it is
> >>>more
> >>>then 100% liner increase in power output when increasing the amount of
> >>>light
> >>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
> >>>it
> >>>would need to be kept cool. due to the fact that they are only 20-30%
> >>>efficent, but I could use the coolant to heat my biodiesel processor,
> >>>then
> >>>the hot water going into my home before a tankless heater. If I were to
> >>>get
> >>>a grid tied inverter It would suppliment my normal power useage and maby
> >>>with netmetering it might come close to canceling out my power
> >>>requirements
> >>>alltogther. a simple temp sensor could be used so if the temp is over
> >>>150f
> >>>in the coolant it will shut down and not collect the sun anymore. As for
> >>>a
> >>>solar tracker that is relative easy with very simple electronics. The
> >>>setup
> >>>to hold everything would be a simple build for most people who can make
> >>>their own biodiesel processor. And If I base it off a 7 meter dish I can
> >>>get
> >>>those free. I just have to use the labor to remove it.
> >>>
> >>>Logan Vilas
> >>>- Original Message -
> >>>From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> >>>To: 
> >>>Sent: Friday, May 12, 2006 3:59 PM
> >>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> >>>
> >>>
> >>>
> >>>>I am speaking mostly from experience, from what I have seen work and
> >>>>fail in the field, and what I can buy to install for my clients. The
> >>>>reason I talk about tr

Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

   As we all know, there are a lot of ways to harvest waste heat but the one that stands out in my mind is from a message posted about six months ago. I don't know if this is a solution, but I'm definitely curious to know one way or the other.http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html  1) Oils are generally non-conductive so, the PV cells can be immersed in it without shorting.2.) Some oils can come with fairly good optical qualities - important for passing light to PV and transforming light to electricity.Joe: I remember reading your post about experimenting with black bodies and it looks like you have a background that may be useful here. Maybe you can chime in (if your reading this thread)?Mike  Zeke Yewdall <[EMAIL PROTECTED]>
 wrote:  This is basically what I did. kludging would be the word for it, asabout once a week it would have a catestrophic leak and I'd have torebuild it. Worked okay to get research data, but obviuosly not longterm I found that preheating water for domestic hot water (whichcould have final heating done either by real solar thermal collectors,or gas/electric/etc) seemed to be the best. Try to get it too hot andthe efficiency dropped way off (I had water tubes touching the back ofthe PV module, but no front glazing), plus it didn't cool the PV cellsenough to help with electrical efficiency much either. The trick isto size the storage tank and PV area with the daily draw to still getthe cooling effect and not stagnate the tank. I suppose with adifferent collector design you could obtain higher temperatures, andstill
 probably not damage the PV module (unless the circulation loopstagnated, then I'm not sure), but I was going more for cooling thePV, and seeing the collected thermal energy could be useful, ratherthan having high quality thermal energy as the primary goal. Giventhat typical solar thermal DHW system here in the US don't achieve100% solar fraction anyway, I figured that preheat was a decent way togo. If you wanted to go for 100% solar fraction (which is what weshould be doing long term) cascading it with a higher temp solarthermal collector might be alot better.On 5/15/06, Chip Mefford <[EMAIL PROTECTED]>wrote:> Zeke Yewdall wrote:> > This is exactly what I did my master's thesis on. The concept works> > pretty well from a theoretical perspective. I was just investigating> > using water cooling for non-concrentrating PV, but it would work even> > better for concentrating PV. You shouldn't
 really have to deal with> > 1200F, at least if you are talking about water, because the maximum> > working temp for a water based fluid is probably about 400F or so??> > (assuming antifreeze additives and increased pressure). Depends on> > how much pressure you are talking about I guess.> >>> l was thinking of kludging up water jackets for PV panels, to feed> the INFLOW for a small evacuated tube solar heater, preheating the> inflow by 'cooling' the PVs.>> Do you think this makes sense?___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Jason & Katie]

that's just a touchbit extreme...

- Original Message - 
From: Michael Redler
To: Biofuel@sustainablelists.org
Sent: Monday, May 15, 2006 7:25 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules



As we all know, there are a lot of ways to harvest waste heat but the one 
that stands out in my mind is from a message posted about six months ago. I 
don't know if this is a solution, but I'm definitely curious to know one way 
or the other.

http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html

1) Oils are generally non-conductive so, the PV cells can be immersed in it 
without shorting.

2.) Some oils can come with fairly good optical qualities - important for 
passing light to PV and transforming light to electricity.

Joe: I remember reading your post about experimenting with black bodies and 
it looks like you have a background that may be useful here. Maybe you can 
chime in (if your reading this thread)?


Mike


Zeke Yewdall <[EMAIL PROTECTED]> wrote:
This is basically what I did. kludging would be the word for it, as
about once a week it would have a catestrophic leak and I'd have to
rebuild it. Worked okay to get research data, but obviuosly not long
term I found that preheating water for domestic hot water (which
could have final heating done either by real solar thermal collectors,
or gas/electric/etc) seemed to be the best. Try to get it too hot and
the efficiency dropped way off (I had water tubes touching the back of
the PV module, but no front glazing), plus it didn't cool the PV cells
enough to help with electrical efficiency much either. The trick is
to size the storage tank and PV area with the daily draw to still get
the cooling effect and not stagnate the tank. I suppose with a
different collector design you could obtain higher temperatures, and
still probably not damage the PV module (unless the circulation loop
stagnated, then I'm not sure), but I was going more for cooling the
PV, and seeing the collected thermal energy could be useful, rather
than having high quality thermal energy as the primary goal. Given
that typical solar thermal DHW system here in the US don't achieve
100% solar fraction anyway, I figured that preheat was a decent way to
go. If you wanted to go for 100% solar fraction (which is what we
should be doing long term) cascading it with a higher temp solar
thermal collector might be alot better.

On 5/15/06, Chip Mefford wrote:
> Zeke Yewdall wrote:
> > This is exactly what I did my master's thesis on. The concept works
> > pretty well from a theoretical perspective. I was just investigating
> > using water cooling for non-concrentrating PV, but it would work even
> > better for concentrating PV. You shouldn't really have to deal with
> > 1200F, at least if you are talking about water, because the maximum
> > working temp for a water based fluid is probably about 400F or so??
> > (assuming antifreeze additives and increased pressure). Depends on
> > how much pressure you are talking about I guess.
> >
>
> l was thinking of kludging up water jackets for PV panels, to feed
> the INFLOW for a small evacuated tube solar heater, preheating the
> inflow by 'cooling' the PVs.
>
> Do you think this makes sense?




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Re: [Biofuel] Solar Concentrator & PV Modules

[Jason & Katie]

Mr. Yewdall and listers,

i have some images floating around in my head that i havent put to media 
yet, but they involve fluid cooled PV and heat sinks, and all sorts of odd 
junk that may or may not work. care to toss a few ideas in the pot and see 
if we can boil down something useful? i will try to make some decent 
drawings and scan them in, as soon as i get my computer re-arranged (new 
apartment) ask for a copy, and ill 'mail it to you

- Original Message - 
From: "Zeke Yewdall" <[EMAIL PROTECTED]>
To: 
Sent: Monday, May 15, 2006 7:11 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


> Google Richard Komp.  His book is called something like "practical
> photovoltaics".  In the back of it, he's got a design for a
> concentrating PV/thermal collectors.  I haven't looked at it for a
> while, but if I recall, he soldered a copper plate to a copper pipe,
> then glued the PV cells to the copper plate with silicon glue, maybe
> with a piece of plastic in between to make sure it didn't short out???
> Can't vouch that I remember the details right, but that's what I
> recall.  Then a semi-parabolic trough reflector to concentrate about 3
> or 4 suns on it.
>
> On 5/15/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
>> aha, this is where i find a new idea.
>>
>> the dielectric heat grease used between processors and heat sinks 
>> /should/
>> work to electrically insulate the cell from the water pack (not jackets, 
>> a
>> flat sleeve covering the back with circulated coolant completely filling 
>> it)
>> while conducting heat into the cooling vanes in the water pack, 
>> eliminating
>> the risk of breakage, just as you say. the goop isnt exactly cheap, but 
>> it
>> works rather effectively on high temp applications.
>>
>> - Original Message -
>> From: "Joe Street" <[EMAIL PROTECTED]>
>> To: 
>> Sent: Monday, May 15, 2006 9:26 AM
>> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>
>>
>> > Silicon is quite fragile especially the thin polysilicon material used
>> > in cells.  You are right but any water pressure would break the cells.
>> > You need to bond them onto a heat conducting back plate like copper or
>> > aluminum with a heat conducting cement.  Aso the back is an electrical
>> > contact so you need isolation there.
>> >
>> > Joe
>> >
>> > Jason & Katie wrote:
>> >
>> >> in theory, if one could find a way to waterproof the back of a PV cell 
>> >> it
>> >> could be used as the heat-side plate in this concentrator/boiler found 
>> >> at
>> >> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you 
>> >> could
>> >> safely increase the power range of a smaller PV cell without too 
>> >> horrible
>> >> of
>> >> a heat loss. the problem is finding a sealing substance that wont melt 
>> >> or
>> >> burn under these 1200*F temperatures.
>> >>
>> >>
>> >> - Original Message -
>> >> From: "logan vilas" <[EMAIL PROTECTED]>
>> >> To: 
>> >> Sent: Friday, May 12, 2006 4:54 PM
>> >> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>> >>
>> >>
>> >>
>> >>>I am working with the idea of building my own Concentrator with about 
>> >>>50
>> >>>times the mirror space then collector space. That Is why the question 
>> >>>was
>> >>>asked in the first place I was wondering if placeing a 50watt solar 
>> >>>panel
>> >>>at
>> >>>the focal point would increase the power output. I've read that it is
>> >>>more
>> >>>then 100% liner increase in power output when increasing the amount of
>> >>>light
>> >>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I 
>> >>>know
>> >>>it
>> >>>would need to be kept cool. due to the fact that they are only 20-30%
>> >>>efficent, but I could use the coolant to heat my biodiesel processor,
>> >>>then
>> >>>the hot water going into my home before a tankless heater. If I were 
>> >>>to
>> >>>get
>> >>>a grid tied inverter It would suppliment my normal power useage and 
>> >>>maby
>> >>>with netmetering it might come close to canceling out my power
>> >&g

Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

What about the liquid PVs??  I think that Konarka is developing one of
those.  And a company in Austrailia.  They supposedly had some
pre-production prototypes about a year ago, but I haven't seen
commercial ones yet.  They use some sort of nano-crystal, and liquid
inside, which can be replaced in 10 years when it degrades

http://www.konarka.com/   Hmm.  Looking at the website, it looks like
it's not the Konarka stuff.  I'll try to find the website of the
australian one.

Zeke

On 5/15/06, Jason & Katie <[EMAIL PROTECTED]> wrote:
> that's just a touchbit extreme...
>
> - Original Message -
> From: Michael Redler
> To: Biofuel@sustainablelists.org
> Sent: Monday, May 15, 2006 7:25 PM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>
> As we all know, there are a lot of ways to harvest waste heat but the one
> that stands out in my mind is from a message posted about six months ago. I
> don't know if this is a solution, but I'm definitely curious to know one way
> or the other.
>
> http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html
>
> 1) Oils are generally non-conductive so, the PV cells can be immersed in it
> without shorting.
>
> 2.) Some oils can come with fairly good optical qualities - important for
> passing light to PV and transforming light to electricity.
>
> Joe: I remember reading your post about experimenting with black bodies and
> it looks like you have a background that may be useful here. Maybe you can
> chime in (if your reading this thread)?
>
>
> Mike
>
>
> Zeke Yewdall <[EMAIL PROTECTED]> wrote:
> This is basically what I did. kludging would be the word for it, as
> about once a week it would have a catestrophic leak and I'd have to
> rebuild it. Worked okay to get research data, but obviuosly not long
> term I found that preheating water for domestic hot water (which
> could have final heating done either by real solar thermal collectors,
> or gas/electric/etc) seemed to be the best. Try to get it too hot and
> the efficiency dropped way off (I had water tubes touching the back of
> the PV module, but no front glazing), plus it didn't cool the PV cells
> enough to help with electrical efficiency much either. The trick is
> to size the storage tank and PV area with the daily draw to still get
> the cooling effect and not stagnate the tank. I suppose with a
> different collector design you could obtain higher temperatures, and
> still probably not damage the PV module (unless the circulation loop
> stagnated, then I'm not sure), but I was going more for cooling the
> PV, and seeing the collected thermal energy could be useful, rather
> than having high quality thermal energy as the primary goal. Given
> that typical solar thermal DHW system here in the US don't achieve
> 100% solar fraction anyway, I figured that preheat was a decent way to
> go. If you wanted to go for 100% solar fraction (which is what we
> should be doing long term) cascading it with a higher temp solar
> thermal collector might be alot better.
>
> On 5/15/06, Chip Mefford wrote:
> > Zeke Yewdall wrote:
> > > This is exactly what I did my master's thesis on. The concept works
> > > pretty well from a theoretical perspective. I was just investigating
> > > using water cooling for non-concrentrating PV, but it would work even
> > > better for concentrating PV. You shouldn't really have to deal with
> > > 1200F, at least if you are talking about water, because the maximum
> > > working temp for a water based fluid is probably about 400F or so??
> > > (assuming antifreeze additives and increased pressure). Depends on
> > > how much pressure you are talking about I guess.
> > >
> >
> > l was thinking of kludging up water jackets for PV panels, to feed
> > the INFLOW for a small evacuated tube solar heater, preheating the
> > inflow by 'cooling' the PVs.
> >
> > Do you think this makes sense?
>
>
>
>
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>
> Search the combined Biofuel and Biofuels-biz list archives (50,000
> messages):
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>
>
>
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> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.5.6/338 - Release Date: 5/12/2006
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&

Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

What does extreme mean?The way I see it, there is probably less materials (no special methods for interfacing PV panel and cooling). I visualize the PV panels in a clear, oil tight enclosure with an inlet, outlet, a length of tubing, heat exchanger (radiator) and circulating pump. As far as hardware is concerned, I don't see this as a huge departure from what we've already been talking about.Now, this thread contains lot of "it won't work" type statements which are not supported with a hell of a lot of information. Simply put, it's a bit of a turn-off.     So, if you have a position that questions the validity of an idea, please back it up with something more than "that's just a touchbit extreme...".Thank you in advance.Mike  Jason & Katie <[EMAIL PROTECTED]> wrote:  that's just a touchbit extreme...- Original Message - From: Michael RedlerTo: Biofuel@sustainablelists.orgSent: Monday, May 15, 2006 7:25 PMSubject: Re: [Biofuel] Solar Concentrator & PV ModulesAs we all know, there are a lot of ways to harvest waste heat but the one that stands out in my mind is from a message posted about six months ago. I don't know if this is a solution, but I'm definitely curious to know one way or the other.http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html1) Oils are generally non-conductive so, the PV cells can be immersed in it without shorting.2.) Some oils can come with fairly good optical qualities - important for passing light to PV and transforming light to electricity.Joe: I remember reading your post about experimenting with black bodies and it looks like you have a background that may be useful
 here. Maybe you can chime in (if your reading this thread)?Mike[snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

Zeke,     Why are you concentrating on emerging technology for purchase when the purpose of this forum encourages the opposite? This is especially true when the discussion is about technology which is accessible to most people (at least most people on this list).Fill a glass box with PV and clear oil. If there is a problem with this application, please let me know. I'm not too proud to concede that I may have missed something.What would Schumacher do?MikeZeke Yewdall <[EMAIL PROTECTED]> wrote:  What about the liquid PVs?? I think that Konarka is developing one ofthose. And a company in Austrailia. They supposedly had somepre-production prototypes about a year ago, but I haven't seencommercial ones yet. They use some sort of nano-crystal, and liquidinside,
 which can be replaced in 10 years when it degradeshttp://www.konarka.com/ Hmm. Looking at the website, it looks likeit's not the Konarka stuff. I'll try to find the website of theaustralian one.Zeke[snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Jason & Katie]

i wasnt talking about your idea, i was speaking of the computer.

anyway if you were to go about it this way, you would need a "white oil" 
which is totally clear, and colorless because any color or particulates 
would lower the applied sunlight. this would produce more heat, yes, but the 
electrical power would be reduced. from an application standpoint the 
question is "is the tradeoff worth it?" it all depends on what results you 
are after.

- Original Message - 
From: Michael Redler
To: Biofuel@sustainablelists.org
Sent: Monday, May 15, 2006 8:17 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


What does extreme mean?

The way I see it, there is probably less materials (no special methods for 
interfacing PV panel and cooling). I visualize the PV panels in a clear, oil 
tight enclosure with an inlet, outlet, a length of tubing, heat exchanger 
(radiator) and circulating pump. As far as hardware is concerned, I don't 
see this as a huge departure from what we've already been talking about.

Now, this thread contains lot of "it won't work" type statements which are 
not supported with a hell of a lot of information. Simply put, it's a bit of 
a turn-off.

So, if you have a position that questions the validity of an idea, please 
back it up with something more than "that's just a touchbit extreme...".

Thank you in advance.

Mike


Jason & Katie <[EMAIL PROTECTED]> wrote:
that's just a touchbit extreme...

- Original Message - 
From: Michael Redler
To: Biofuel@sustainablelists.org
Sent: Monday, May 15, 2006 7:25 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules



As we all know, there are a lot of ways to harvest waste heat but the one
that stands out in my mind is from a message posted about six months ago. I
don't know if this is a solution, but I'm definitely curious to know one way
or the other.

http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html

1) Oils are generally non-conductive so, the PV cells can be immersed in it
without shorting.

2.) Some oils can come with fairly good optical qualities - important for
passing light to PV and transforming light to electricity.

Joe: I remember reading your post about experimenting with black bodies and
it looks like you have a background that may be useful here. Maybe you can
chime in (if your reading this thread)?


Mike

[snip]



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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

Ah, the computer. Understood.   How about food grade, Citation™ and Avatech™ White Mineral Oil (for example)?     http://www.avatarcorp.com/products_list.php/inid/3/catid/89/org/indus/catn/White%20Mineral%20Oil/?source=google     ...although mineral oils might actually conduct electricity. I haven't done enough research yet. In any event, I think it's quite possible to have a clear, non-conductive oil with relatively good heat transfer qualities.     There are optical fluids (oils) used in the manufacture of some high power microscopes (for example).     I snipped a portion from a site about oil cooled computers. I think it's applicable here.     "The gunk factor and the
 place smelling like vegetable oil makes me think that a petrochemical or mineral oil would be the best bet.. I suppose any reasonably non-conductive fluid medium would work. Heh.. Thinned-down petroleum jelly for a porn server? I wonder how conductive gasoline is.."     http://www.museumofhoaxes.com/hoax/weblog/comments/3153/      I like their spunk!        Mike Jason & Katie <[EMAIL PROTECTED]> wrote:  i wasnt talking about your idea, i was speaking of the computer.anyway if you were to go about it this way, you would need a "white oil" which is totally clear, and colorless because any color or particulates would lower the applied sunlight.
 this would produce more heat, yes, but the electrical power would be reduced. from an application standpoint the question is "is the tradeoff worth it?" it all depends on what results you are after.- Original Message - From: Michael RedlerTo: Biofuel@sustainablelists.orgSent: Monday, May 15, 2006 8:17 PMSubject: Re: [Biofuel] Solar Concentrator & PV ModulesWhat does extreme mean?The way I see it, there is probably less materials (no special methods for interfacing PV panel and cooling). I visualize the PV panels in a clear, oil tight enclosure with an inlet, outlet, a length of tubing, heat exchanger (radiator) and circulating pump. As far as hardware is concerned, I don't see this as a huge departure from what we've already been talking about.Now, this thread contains lot of "it won't work" type statements which are not supported with a hell of a lot of information. Simply put,
 it's a bit of a turn-off.So, if you have a position that questions the validity of an idea, please back it up with something more than "that's just a touchbit extreme...".Thank you in advance.MikeJason & Katie <[EMAIL PROTECTED]>wrote:that's just a touchbit extreme...- Original Message - From: Michael RedlerTo: Biofuel@sustainablelists.orgSent: Monday, May 15, 2006 7:25 PMSubject: Re: [Biofuel] Solar Concentrator & PV ModulesAs we all know, there are a lot of ways to harvest waste heat but the onethat stands out in my mind is from a message posted about six months ago. Idon't know if this is a solution, but I'm definitely curious to know one wayor the other.http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html1) Oils are generally non-conductive so, the PV cells can be immersed in itwithout shorting.2.) Some oils
 can come with fairly good optical qualities - important forpassing light to PV and transforming light to electricity.Joe: I remember reading your post about experimenting with black bodies andit looks like you have a background that may be useful here. Maybe you canchime in (if your reading this thread)?Mike[snip]___
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Re: [Biofuel] Solar Concentrator & PV Modules

[Joe Street]

Well it might work to have the cell immersed behind a glass or fused 
silica window yes!  I notice with veggie oil and even moreso with BD 
that heating with an immersion heater is much more prone to boiling on 
the heater surface with BD and oil which leads me to believe that the 
specific heat capacity is worse (less) than water. Pure water is a good 
insulator and is ideal with a specific heat capacity of unity but it is 
hard to keep it pure enough to be insulating especially if it is in 
contact with metals. Freon would be ideal if not for the environmental 
issues. :(

Joe


Michael Redler wrote:

>  
> As we all know, there are a lot of ways to harvest waste heat but the 
> one that stands out in my mind is from a message posted about six months 
> ago. I don't know if this is a solution, but I'm definitely curious to 
> know one way or the other.
> 
> http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html
> 
> 1) Oils are generally non-conductive so, the PV cells can be immersed in 
> it without shorting.
> 
> 2.) Some oils can come with fairly good optical qualities - important 
> for passing light to PV and transforming light to electricity.
> 
> Joe: I remember reading your post about experimenting with black bodies 
> and it looks like you have a background that may be useful here. Maybe 
> you can chime in (if your reading this thread)?
> 
> 
> Mike
> 
> 
> */Zeke Yewdall <[EMAIL PROTECTED]>/* wrote:
> 
> This is basically what I did. kludging would be the word for it, as
> about once a week it would have a catestrophic leak and I'd have to
> rebuild it. Worked okay to get research data, but obviuosly not long
> term I found that preheating water for domestic hot water (which
> could have final heating done either by real solar thermal collectors,
> or gas/electric/etc) seemed to be the best. Try to get it too hot and
> the efficiency dropped way off (I had water tubes touching the back of
> the PV module, but no front glazing), plus it didn't cool the PV cells
> enough to help with electrical efficiency much either. The trick is
> to size the storage tank and PV area with the daily draw to still get
> the cooling effect and not stagnate the tank. I suppose with a
> different collector design you could obtain higher temperatures, and
> still probably not damage the PV module (unless the circulation loop
> stagnated, then I'm not sure), but I was going more for cooling the
> PV, and seeing the collected thermal energy could be useful, rather
> than having high quality thermal energy as the primary goal. Given
> that typical solar thermal DHW system here in the US don't achieve
> 100% solar fraction anyway, I figured that preheat was a decent way to
> go. If you wanted to go for 100% solar fraction (which is what we
> should be doing long term) cascading it with a higher temp solar
> thermal collector might be alot better.
> 
> On 5/15/06, Chip Mefford wrote:
>  > Zeke Yewdall wrote:
>  > > This is exactly what I did my master's thesis on. The concept works
>  > > pretty well from a theoretical perspective. I was just
> investigating
>  > > using water cooling for non-concrentrating PV, but it would
> work even
>  > > better for concentrating PV. You shouldn't really have to deal with
>  > > 1200F, at least if you are talking about water, because the maximum
>  > > working temp for a water based fluid is probably about 400F or so??
>  > > (assuming antifreeze additives and increased pressure). Depends on
>  > > how much pressure you are talking about I guess.
>  > >
>  >
>  > l was thinking of kludging up water jackets for PV panels, to feed
>  > the INFLOW for a small evacuated tube solar heater, preheating the
>  > inflow by 'cooling' the PVs.
>  >
>  > Do you think this makes sense?
> 
> 
> 
> 
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Re: [Biofuel] Solar Concentrator & PV Modules

[Joe Street]

Hi Jason;

Careful.  The thermal grease is not sufficient as an insulator. It also 
doesn't bond the cell to the backing plate.  It would have to be clamped 
somehow which is not useful. Often there is a mica sheet or a 
thermopolymer in there when that grease is used on a transistor or 
thyristor device. You should take a look at the epoxies available for 
this job.  I believe Epotek or Ablestik will have something suitable. 
BTW I have no interest in these companies but have used their products 
with great success in the past for attaching semiconductor chips to 
ceramic and metal packages.  You can get both thermal/electrical 
conductive or thermal conductive electrical isolating which is what you 
want.

Joe

Jason & Katie wrote:

> aha, this is where i find a new idea.
> 
> the dielectric heat grease used between processors and heat sinks /should/ 
> work to electrically insulate the cell from the water pack (not jackets, a 
> flat sleeve covering the back with circulated coolant completely filling it) 
> while conducting heat into the cooling vanes in the water pack, eliminating 
> the risk of breakage, just as you say. the goop isnt exactly cheap, but it 
> works rather effectively on high temp applications.
> 
> - Original Message - 
> From: "Joe Street" <[EMAIL PROTECTED]>
> To: 
> Sent: Monday, May 15, 2006 9:26 AM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
> 
> 
> 
>>Silicon is quite fragile especially the thin polysilicon material used
>>in cells.  You are right but any water pressure would break the cells.
>>You need to bond them onto a heat conducting back plate like copper or
>>aluminum with a heat conducting cement.  Aso the back is an electrical
>>contact so you need isolation there.
>>
>>Joe
>>
>>Jason & Katie wrote:
>>
>>
>>>in theory, if one could find a way to waterproof the back of a PV cell it
>>>could be used as the heat-side plate in this concentrator/boiler found at
>>>(or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
>>>safely increase the power range of a smaller PV cell without too horrible 
>>>of
>>>a heat loss. the problem is finding a sealing substance that wont melt or
>>>burn under these 1200*F temperatures.
>>>
>>>
>>>- Original Message - 
>>>From: "logan vilas" <[EMAIL PROTECTED]>
>>>To: 
>>>Sent: Friday, May 12, 2006 4:54 PM
>>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>>
>>>
>>>
>>>
>>>>I am working with the idea of building my own Concentrator with about 50
>>>>times the mirror space then collector space. That Is why the question was
>>>>asked in the first place I was wondering if placeing a 50watt solar panel
>>>>at
>>>>the focal point would increase the power output. I've read that it is 
>>>>more
>>>>then 100% liner increase in power output when increasing the amount of
>>>>light
>>>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
>>>>it
>>>>would need to be kept cool. due to the fact that they are only 20-30%
>>>>efficent, but I could use the coolant to heat my biodiesel processor, 
>>>>then
>>>>the hot water going into my home before a tankless heater. If I were to
>>>>get
>>>>a grid tied inverter It would suppliment my normal power useage and maby
>>>>with netmetering it might come close to canceling out my power
>>>>requirements
>>>>alltogther. a simple temp sensor could be used so if the temp is over 
>>>>150f
>>>>in the coolant it will shut down and not collect the sun anymore. As for 
>>>>a
>>>>solar tracker that is relative easy with very simple electronics. The
>>>>setup
>>>>to hold everything would be a simple build for most people who can make
>>>>their own biodiesel processor. And If I base it off a 7 meter dish I can
>>>>get
>>>>those free. I just have to use the labor to remove it.
>>>>
>>>>Logan Vilas
>>>>- Original Message - 
>>>>From: "Zeke Yewdall" <[EMAIL PROTECTED]>
>>>>To: 
>>>>Sent: Friday, May 12, 2006 3:59 PM
>>>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>>>
>>>>
>>>>
>>>>
>>>>>I am speaking mostly from experience, from what I have seen work and
>>>>>fail in the field, and what I 

Re: [Biofuel] Solar Concentrator & PV Modules

[Hakan Falk]

Mike,

Many of the high voltage transformers in 
electricity distribution are filled with oil for 
insulation and cooling purposes. In this case I 
belive it is mineral oils, but it is many years 
(40) since I worked with this and do not completely trust my memory.

Hakan

At 14:54 16/05/2006, you wrote:
>Ah, the computer. Understood.
>
>How about food grade, Citation™ and Avatech™ White Mineral Oil (for example)?
>
><http://www.avatarcorp.com/products_list.php/inid/3/catid/89/org/indus/catn/White%20Mineral%20Oil/?source=google>http://www.avatarcorp.com/products_list.php/inid/3/catid/89/org/indus/catn/White%20Mineral%20Oil/?source=google
>
>...although mineral oils might actually conduct 
>electricity. I haven't done enough research yet. 
>In any event, I think it's quite possible to 
>have a clear, non-conductive oil with relatively good heat transfer qualities.
>
>There are optical fluids (oils) used in the 
>manufacture of some high power microscopes (for example).
>
>I snipped a portion from a site about oil cooled 
>computers. I think it's applicable here.
>
>"The gunk factor and the place smelling like 
>vegetable oil makes me think that a 
>petrochemical or mineral oil would be the best 
>bet.. I suppose any reasonably non-conductive 
>fluid medium would work. Heh.. Thinned-down 
>petroleum jelly for a porn server? I wonder how conductive gasoline is.."
>
><http://www.museumofhoaxes.com/hoax/weblog/comments/3153/>http://www.museumofhoaxes.com/hoax/weblog/comments/3153/
> 
>
>
>I like their spunk!
>
>
>Mike
>
>Jason & Katie <[EMAIL PROTECTED]> wrote:
>i wasnt talking about your idea, i was speaking of the computer.
>
>anyway if you were to go about it this way, you would need a "white oil"
>which is totally clear, and colorless because any color or particulates
>would lower the applied sunlight. this would produce more heat, yes, but the
>electrical power would be reduced. from an application standpoint the
>question is "is the tradeoff worth it?" it all depends on what results you
>are after.
>
>- Original Message -
>From: Michael Redler
>To: Biofuel@sustainablelists.org
>Sent: Monday, May 15, 2006 8:17 PM
>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>What does extreme mean?
>
>The way I see it, there is probably less materials (no special methods for
>interfacing PV panel and cooling). I visualize the PV panels in a clear, oil
>tight enclosure with an inlet, outlet, a length of tubing, heat exchanger
>(radiator) and circulating pump. As far as hardware is concerned, I don't
>see this as a huge departure from what we've already been talking about.
>
>Now, this thread contains lot of "it won't work" type statements which are
>not supported with a hell of a lot of information. Simply put, it's a bit of
>a turn-off.
>
>So, if you have a position that questions the validity of an idea, please
>back it up with something more than "that's just a touchbit extreme...".
>
>Thank you in advance.
>
>Mike
>
>
>Jason & Katie wrote:
>that's just a touchbit extreme...
>
>- Original Message -
>From: Michael Redler
>To: Biofuel@sustainablelists.org
>Sent: Monday, May 15, 2006 7:25 PM
>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>
>As we all know, there are a lot of ways to harvest waste heat but the one
>that stands out in my mind is from a message posted about six months ago. I
>don't know if this is a solution, but I'm definitely curious to know one way
>or the other.
>
>http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html
>
>1) Oils are generally non-conductive so, the PV cells can be immersed in it
>without shorting.
>
>2.) Some oils can come with fairly good optical qualities - important for
>passing light to PV and transforming light to electricity.
>
>Joe: I remember reading your post about experimenting with black bodies and
>it looks like you have a background that may be useful here. Maybe you can
>chime in (if your reading this thread)?
>
>
>Mike
>
>[snip]
>
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Re: [Biofuel] Solar Concentrator & PV Modules

[Chip Mefford]

Hakan Falk wrote:
> Mike,
> 
> Many of the high voltage transformers in 
> electricity distribution are filled with oil for 
> insulation and cooling purposes. 
> In this case I 
> belive it is mineral oils, but it is many years 
> (40) since I worked with this and do not completely trust my memory.

They were,

and 40 years ago, they were filled with that marvelous compound
that did everything exactly right. Polychlorinatedbiphenol.

Great stuff all in all, just had one drawback

>SNIP

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Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

Who says that the PV cells have to be immersed in the oil?     If the modules were in the glass box and standing (more or less) upright, the oil coolant could simply be cascaded over the modules. Even if the oil had relatively high photoabsorption compared to water (for example), there would only be a thin film to penetrate.     Any thoughts?     Mike Chip Mefford <[EMAIL PROTECTED]> wrote:  Hakan Falk wrote:> Mike,> > Many of the high voltage transformers in > electricity distribution are filled with oil for > insulation and cooling purposes. > In this case I > belive it is mineral oils, but it is many years > (40) since I worked with this and do not completely trust my
 memory.They were,and 40 years ago, they were filled with that marvelous compoundthat did everything exactly right. Polychlorinatedbiphenol.Great stuff all in all, just had one drawback>SNIP___
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Re: [Biofuel] Solar Concentrator & PV Modules

[logan vilas]

The best heat transfer pastes for processors has silver in it and I belive 
silver is conductive.

Logan Vilas
- Original Message - 
From: "Jason & Katie" <[EMAIL PROTECTED]>
To: 
Sent: Monday, May 15, 2006 7:02 PM
Subject: Re: [Biofuel] Solar Concentrator & PV Modules


> aha, this is where i find a new idea.
>
> the dielectric heat grease used between processors and heat sinks /should/
> work to electrically insulate the cell from the water pack (not jackets, a
> flat sleeve covering the back with circulated coolant completely filling 
> it)
> while conducting heat into the cooling vanes in the water pack, 
> eliminating
> the risk of breakage, just as you say. the goop isnt exactly cheap, but it
> works rather effectively on high temp applications.
>
> - Original Message - 
> From: "Joe Street" <[EMAIL PROTECTED]>
> To: 
> Sent: Monday, May 15, 2006 9:26 AM
> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>
>
>> Silicon is quite fragile especially the thin polysilicon material used
>> in cells.  You are right but any water pressure would break the cells.
>> You need to bond them onto a heat conducting back plate like copper or
>> aluminum with a heat conducting cement.  Aso the back is an electrical
>> contact so you need isolation there.
>>
>> Joe
>>
>> Jason & Katie wrote:
>>
>>> in theory, if one could find a way to waterproof the back of a PV cell 
>>> it
>>> could be used as the heat-side plate in this concentrator/boiler found 
>>> at
>>> (or after) http://www.ida.net/users/tetonsl/solar/page_46.htm you could
>>> safely increase the power range of a smaller PV cell without too 
>>> horrible
>>> of
>>> a heat loss. the problem is finding a sealing substance that wont melt 
>>> or
>>> burn under these 1200*F temperatures.
>>>
>>>
>>> - Original Message - 
>>> From: "logan vilas" <[EMAIL PROTECTED]>
>>> To: 
>>> Sent: Friday, May 12, 2006 4:54 PM
>>> Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>>
>>>
>>>
>>>>I am working with the idea of building my own Concentrator with about 50
>>>>times the mirror space then collector space. That Is why the question 
>>>>was
>>>>asked in the first place I was wondering if placeing a 50watt solar 
>>>>panel
>>>>at
>>>>the focal point would increase the power output. I've read that it is
>>>>more
>>>>then 100% liner increase in power output when increasing the amount of
>>>>light
>>>>on it. a normal panel at 50 watts would be 2500 watts at 50 suns. I know
>>>>it
>>>>would need to be kept cool. due to the fact that they are only 20-30%
>>>>efficent, but I could use the coolant to heat my biodiesel processor,
>>>>then
>>>>the hot water going into my home before a tankless heater. If I were to
>>>>get
>>>>a grid tied inverter It would suppliment my normal power useage and maby
>>>>with netmetering it might come close to canceling out my power
>>>>requirements
>>>>alltogther. a simple temp sensor could be used so if the temp is over
>>>>150f
>>>>in the coolant it will shut down and not collect the sun anymore. As for
>>>>a
>>>>solar tracker that is relative easy with very simple electronics. The
>>>>setup
>>>>to hold everything would be a simple build for most people who can make
>>>>their own biodiesel processor. And If I base it off a 7 meter dish I can
>>>>get
>>>>those free. I just have to use the labor to remove it.
>>>>
>>>>Logan Vilas
>>>>- Original Message - 
>>>>From: "Zeke Yewdall" <[EMAIL PROTECTED]>
>>>>To: 
>>>>Sent: Friday, May 12, 2006 3:59 PM
>>>>Subject: Re: [Biofuel] Solar Concentrator & PV Modules
>>>>
>>>>
>>>>
>>>>>I am speaking mostly from experience, from what I have seen work and
>>>>>fail in the field, and what I can buy to install for my clients. The
>>>>>reason I talk about trackers on large poles is because that is what is
>>>>>commercially sold right now (at least in the US, europe is ahead of us
>>>>>in many areas).  And the biggest reason I see for failed systems is
>>>>>lack of maintenance (mostly batteries, but also anything that moves)

Re: [Biofuel] Solar Concentrator & PV Modules

[John Estill]

It's been about 4 years for me, and yes, bio-based
oils were/are being tested/used by the larger
utilities. A quick google on "bio-based transformer
oil" will bring a bunch of hits.

>Hakan Falk wrote:
>> Mike,
>> 
>> Many of the high voltage transformers in 
>> electricity distribution are filled with oil for 
>> insulation and cooling purposes. 
>> In this case I 
>> belive it is mineral oils, but it is many years 
>> (40) since I worked with this and do not completely
>trust my memory.
>
>They were, and 40 years ago, they were filled with
>that marvelous compound that did everything exactly
>right. Polychlorinatedbiphenol.
>
>Great stuff all in all, just had one drawback
>
>>SNIP





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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

This sounds better.  For one, you don't have a pressurized flat plate,
which would be hard to engineer compared to a tube -- imagine the
pressure on a 3 x 5 foot piece of glass with pressurized fluid behind
it.  Not that a large flat box with pressurized fluid in it would have
to be at very high pressure if it was a drainback type system.  But I
like the cascading fluid better.  You could do it as cascading without
a front cover at all, but then you'd collect loads of dust (and other
debris, animals, etc), so that would over time block more light than
the extra piece of glass.

With the high heat transfer of a liquid though, a system with fluid
touching only the back of the PV cells might be sufficient though.
But then you are back to requiring a filled fluid resevoir instead of
a trickle, since the back of the PV module would be downward facing.
Hmm.

On 5/16/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>
> Who says that the PV cells have to be immersed in the oil?
>
> If the modules were in the glass box and standing (more or less) upright,
> the oil coolant could simply be cascaded over the modules. Even if the oil
> had relatively high photoabsorption compared to water (for example), there
> would only be a thin film to penetrate.
>
> Any thoughts?
>
> Mike
>
>
> Chip Mefford <[EMAIL PROTECTED]> wrote:
>
> Hakan Falk wrote:
> > Mike,
> >
> > Many of the high voltage transformers in
> > electricity distribution are filled with oil for
> > insulation and cooling purposes.
> > In this case I
> > belive it is mineral oils, but it is many years
> > (40) since I worked with this and do not completely trust my memory.
>
> They were,
>
> and 40 years ago, they were filled with that marvelous compound
> that did everything exactly right. Polychlorinatedbiphenol.
>
> Great stuff all in all, just had one drawback
>
> >SNIP
>
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>
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> messages):
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>
>
>
>

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Re: [Biofuel] Solar Concentrator & PV Modules

[Mike Redler]

Yes!!

That's a great observation Zeke! Quite literally, it would be a 
self-cleaning solar collector. Filtration at the pump is something that 
would be an appropriate piece of hardware anyway.

We should all keep this on the back burner until one or some of us have 
the resources to conspire on a prototype..

In my opinion it would be the pinnacle of this forum to develop 
technology together which would be freely accessible to anyone in the 
public domain.

Is there a Patent attorney in the house? I want to know if this thread 
is legally binding, making members of this forum co-inventors under the 
current first-to-invent system in the US.


Mike

Zeke Yewdall wrote:
> This sounds better.  For one, you don't have a pressurized flat plate,
> which would be hard to engineer compared to a tube -- imagine the
> pressure on a 3 x 5 foot piece of glass with pressurized fluid behind
> it.  Not that a large flat box with pressurized fluid in it would have
> to be at very high pressure if it was a drainback type system.  But I
> like the cascading fluid better.  You could do it as cascading without
> a front cover at all, but then you'd collect loads of dust (and other
> debris, animals, etc), so that would over time block more light than
> the extra piece of glass.
>
> With the high heat transfer of a liquid though, a system with fluid
> touching only the back of the PV cells might be sufficient though.
> But then you are back to requiring a filled fluid resevoir instead of
> a trickle, since the back of the PV module would be downward facing.
> Hmm.
>
> On 5/16/06, Michael Redler <[EMAIL PROTECTED]> wrote:
>   
>> Who says that the PV cells have to be immersed in the oil?
>>
>> If the modules were in the glass box and standing (more or less) upright,
>> the oil coolant could simply be cascaded over the modules. Even if the oil
>> had relatively high photoabsorption compared to water (for example), there
>> would only be a thin film to penetrate.
>>
>> Any thoughts?
>>
>> Mike
>>
>>
>> Chip Mefford <[EMAIL PROTECTED]> wrote:
>>
>> Hakan Falk wrote:
>> 
>>> Mike,
>>>
>>> Many of the high voltage transformers in
>>> electricity distribution are filled with oil for
>>> insulation and cooling purposes.
>>> In this case I
>>> belive it is mineral oils, but it is many years
>>> (40) since I worked with this and do not completely trust my memory.
>>>   
>> They were,
>>
>> and 40 years ago, they were filled with that marvelous compound
>> that did everything exactly right. Polychlorinatedbiphenol.
>>
>> Great stuff all in all, just had one drawback
>>
>> 
>>> SNIP


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Re: [Biofuel] Solar Concentrator & PV Modules

[Zeke Yewdall]

Great idea.  I'm a fan of more public domain stuff.

If it were a cascade of liquid going over the surface, how about using
water instead of veggie oil?  You'd get a little evaporation (at least
in dry climates) which would cool it off, but better heat transfer,
and less energy to pump it?  It would essentially be a drainback
system, so the freezing problem would be taken care of.

And in desert climates, you could also circulate the fluid in the
nighttime and cool it (from night sky radiation, and maybe from
evaporationg too, if you used water, not so much with oil), and use it
for air conditioning  I've seen ice on my solar panels in the
morning, when it's not quite below freezing for the air temperature.

On 5/16/06, Mike Redler <[EMAIL PROTECTED]> wrote:
> Yes!!
>
> That's a great observation Zeke! Quite literally, it would be a
> self-cleaning solar collector. Filtration at the pump is something that
> would be an appropriate piece of hardware anyway.
>
> We should all keep this on the back burner until one or some of us have
> the resources to conspire on a prototype..
>
> In my opinion it would be the pinnacle of this forum to develop
> technology together which would be freely accessible to anyone in the
> public domain.
>
> Is there a Patent attorney in the house? I want to know if this thread
> is legally binding, making members of this forum co-inventors under the
> current first-to-invent system in the US.
>
>
> Mike
>
> Zeke Yewdall wrote:
> > This sounds better.  For one, you don't have a pressurized flat plate,
> > which would be hard to engineer compared to a tube -- imagine the
> > pressure on a 3 x 5 foot piece of glass with pressurized fluid behind
> > it.  Not that a large flat box with pressurized fluid in it would have
> > to be at very high pressure if it was a drainback type system.  But I
> > like the cascading fluid better.  You could do it as cascading without
> > a front cover at all, but then you'd collect loads of dust (and other
> > debris, animals, etc), so that would over time block more light than
> > the extra piece of glass.
> >
> > With the high heat transfer of a liquid though, a system with fluid
> > touching only the back of the PV cells might be sufficient though.
> > But then you are back to requiring a filled fluid resevoir instead of
> > a trickle, since the back of the PV module would be downward facing.
> > Hmm.
> >
> > On 5/16/06, Michael Redler <[EMAIL PROTECTED]> wrote:
> >
> >> Who says that the PV cells have to be immersed in the oil?
> >>
> >> If the modules were in the glass box and standing (more or less) upright,
> >> the oil coolant could simply be cascaded over the modules. Even if the oil
> >> had relatively high photoabsorption compared to water (for example), there
> >> would only be a thin film to penetrate.
> >>
> >> Any thoughts?
> >>
> >> Mike
> >>
> >>
> >> Chip Mefford <[EMAIL PROTECTED]> wrote:
> >>
> >> Hakan Falk wrote:
> >>
> >>> Mike,
> >>>
> >>> Many of the high voltage transformers in
> >>> electricity distribution are filled with oil for
> >>> insulation and cooling purposes.
> >>> In this case I
> >>> belive it is mineral oils, but it is many years
> >>> (40) since I worked with this and do not completely trust my memory.
> >>>
> >> They were,
> >>
> >> and 40 years ago, they were filled with that marvelous compound
> >> that did everything exactly right. Polychlorinatedbiphenol.
> >>
> >> Great stuff all in all, just had one drawback
> >>
> >>
> >>> SNIP
>
>
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Re: [Biofuel] Solar Concentrator & PV Modules

[E. C.]

Mikes, Zeke, Chip, Hakan et al;
Greetings -- & thanx for the hope!
   I'm trying to dope out a system to incorporate in a
geodesic-dome structure [utilizing thin-film PV in top
panels to capture sun-source as
heat-transfer/electrical-generation] & also to
accelerate algae-production in a holding tank to
provide biomass to process to BD for transport fuel. 
Trouble is, i'm no chemist or engineer, just a reader
-- this forum is the greatest for idea-generation!!

   i'm not concerned about patents & ownership rights:
 with what i figure is a 10-15-year window of
opportunity to effect change to sustainable living
patterns, we need all the idea-sharing (some call it
theft of intellectual property) we can get, for
survival as a species!

   Specific to this thread:  the cooling fluid across
the PV film doesn't need to be deep if the heat is
transferred & redirected (a radiator?) at a separate
site, right?  Or am i off in left field?

   Sooo much i don't know 

A friend works in an aluminum-extrusion factory, &
says can make the PV-film-holding panels easy -- but i
read that aluminum is a drawback; why not, say,
slotted 2"X6" lumber w/wood keys ??  With the geodesic
design using 1/7 the structure-support needed for
comparable box-type enclosure space, seems this is
still practicable -- 2 X 6 would allow space for
sun-blocking liquid-foam insulation (interior of the
PV, & the circulating algae medium [water], of
course).  I live in Florida, & summer heat is an
issue.  Geodesics are also more wind-resistant (as in
hurricanes, which are becoming more prevalent, bigger,
& more damaging as the global climate degenerates --
at least i'm not right on the coast).

   Enuf of my ramblings -- ideas & corrections are
most  gratefully accepted & acknowledged.  :-)~

Peace to All, & a bettering world
E. Allen C.



  

--- Mike Redler <[EMAIL PROTECTED]> wrote:

> Yes!!
> 
> That's a great observation Zeke! Quite literally, it
> would be a 
> self-cleaning solar collector. Filtration at the
> pump is something that 
> would be an appropriate piece of hardware anyway.
> 
> We should all keep this on the back burner until one
> or some of us have 
> the resources to conspire on a prototype..
> 
> In my opinion it would be the pinnacle of this forum
> to develop 
> technology together which would be freely accessible
> to anyone in the 
> public domain.
> 
> Is there a Patent attorney in the house? I want to
> know if this thread 
> is legally binding, making members of this forum
> co-inventors under the 
> current first-to-invent system in the US.
> 
> 
> Mike
> 
> Zeke Yewdall wrote:
> > This sounds better.  For one, you don't have a
> pressurized flat plate,
> > which would be hard to engineer compared to a tube
> -- imagine the
> > pressure on a 3 x 5 foot piece of glass with
> pressurized fluid behind
> > it.  Not that a large flat box with pressurized
> fluid in it would have
> > to be at very high pressure if it was a drainback
> type system.  But I
> > like the cascading fluid better.  You could do it
> as cascading without
> > a front cover at all, but then you'd collect loads
> of dust (and other
> > debris, animals, etc), so that would over time
> block more light than
> > the extra piece of glass.
> >
> > With the high heat transfer of a liquid though, a
> system with fluid
> > touching only the back of the PV cells might be
> sufficient though.
> > But then you are back to requiring a filled fluid
> resevoir instead of
> > a trickle, since the back of the PV module would
> be downward facing.
> > Hmm.
> >
> > On 5/16/06, Michael Redler <[EMAIL PROTECTED]>
> wrote:
> >   
> >> Who says that the PV cells have to be immersed in
> the oil?
> >>
> >> If the modules were in the glass box and standing
> (more or less) upright,
> >> the oil coolant could simply be cascaded over the
> modules. Even if the oil
> >> had relatively high photoabsorption compared to
> water (for example), there
> >> would only be a thin film to penetrate.
> >>
> >> Any thoughts?
> >>
> >> Mike
> >>
> >>
> >> Chip Mefford <[EMAIL PROTECTED]> wrote:
> >>
> >> Hakan Falk wrote:
> >> 
> >>> Mike,
> >>>
> >>> Many of the high voltage transformers in
> >>> electricity distribution are filled with oil for
> >>> insulation and cooling purposes.
> >>> In this case I
> >>> belive it is mineral oils, but it is many years
> >>> (40) since I worked with this and do not
> completely trust my memory.
> >>>   
> >> They were,
> >>
> >> and 40 years ago, they were filled with that
> marvelous compound
> >> that did everything exactly right.
> Polychlorinatedbiphenol.
> >>
> >> Great stuff all in all, just had one drawback
> >>
> >> 
> >>> SNIP
> 
> 
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> 
> Search the combined Biofuel and 

Re: [Biofuel] Solar Concentrator & PV Modules

[Michael Redler]

E. Allen C.  You wrote: "Specific to this thread:  the cooling fluid acrossthe PV film doesn't need to be deep if the heat istransferred & redirected (a radiator?) at a separatesite, right?  Or am i off in left field?"     Your right-on, E.     You wrote: "A friend works in an aluminum-extrusion factory..."     Whoa! ...the holy grail of DIY of heat transfer. Go for it!     JTF is huge and might have some info on this. It's also been discussed in this forum. I recommend you search the archives.     Finally, the search engine is your friend! Have you tried www.dogpile.com? Important search words include:     Peltier or "Peltier effect"  "waste heat"  "absorption"  cogeneration   
     Good luck!     Mike        "E. C." <[EMAIL PROTECTED]> wrote:  Mikes, Zeke, Chip, Hakan et al;Greetings -- & thanx for the hope!I'm trying to dope out a system to incorporate in ageodesic-dome structure [utilizing thin-film PV in toppanels to capture sun-source asheat-transfer/electrical-generation] & also toaccelerate algae-production in a holding tank toprovide biomass to process to BD for transport fuel. Trouble is, i'm no chemist or engineer, just a reader-- this forum is the greatest for idea-generation!!i'm not concerned about patents & ownership rights:with what i figure is a 10-15-year window ofopportunity to effect change to sustainable livingpatterns, we need all the
 idea-sharing (some call ittheft of intellectual property) we can get, forsurvival as a species!Specific to this thread: the cooling fluid acrossthe PV film doesn't need to be deep if the heat istransferred & redirected (a radiator?) at a separatesite, right? Or am i off in left field?Sooo much i don't know A friend works in an aluminum-extrusion factory, &says can make the PV-film-holding panels easy -- but iread that aluminum is a drawback; why not, say,slotted 2"X6" lumber w/wood keys ?? With the geodesicdesign using 1/7 the structure-support needed forcomparable box-type enclosure space, seems this isstill practicable -- 2 X 6 would allow space forsun-blocking liquid-foam insulation (interior of thePV, & the circulating algae medium [water], ofcourse). I live in Florida, & summer heat is anissue. Geodesics are also more wind-resistant (as inhurricanes, which are
 becoming more prevalent, bigger,& more damaging as the global climate degenerates --at least i'm not right on the coast).Enuf of my ramblings -- ideas & corrections aremost gratefully accepted & acknowledged. :-)~Peace to All, & a bettering worldE. Allen C.___
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