Re: [RE-wrenches] Bifacial Modules
Drake This is an interesting topic, Q, do bi-facials really work? A, it depends, Solution, low profile on a roof may not so much its all about reflectivity so higher off the ground(roof) the better. A parking lot canopy might see a measurable improvement if the parking lot is a light reflective color, dark not so much, single rows vs large arrays also better, further north from the equator can help, snow on the ground will help, bottom line is, it is a real hard number to qualify until you can compare your actual location, I sell them and state very clearly what ever you get is a bonus that's all. I know some many differ from this but telling someone they will get X% back is going to spell disaster, it will be a hard sell to tell the property owner that he must keep his panels and roof clean to gain any additional results. Fun Times On Mon, Aug 8, 2022 at 1:27 PM Drake Chamberlin via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Are bifacial modules good products? Do they really perform as > advertised? > > We have a potential project where they would be used on a white roof. > Would that be an ideal situation? > > Thanks, > > Drake > > Drake Chamberlin > Athens Electric LLC > Ohio Electrical Contractor’s License 44810 > CO Master Electrician’s License 4526 > NABCEP Certified PV Installation Professional > > > -- > ___ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > > ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules on pole mounts
I have used the old Sanyo bifacials on a Pergola in snow country with very good results. They had frames though and have held up really well. I have some single axis trackers at my place that I would really love to update the modules with the new Panasonic bi's. The frames have always been the thing that stopped me. I will follow your post here and appreciate any updates. --Dave > Hi Wrenches, > > We have started thinking about experimenting with bifacial modules on pole > mounts in remote locations where snow is a big issue; the idea being we > could still be collecting some energy when the front of the module is > covered in snow. I don't have any experience with bifacial modules, I am > curious if anyone has tried this? Also, since most bifacial modules are > frameless, how is the racking configured? > > Thanks in advance > > > > -- > > > > Mac Lewis > > *"Yo solo sé que no sé nada." -Sócrates* > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail offgridso...@sti.net text 209 813 0060 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules
Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith From: Phil Undercuffler solarp...@gmail.com To: Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Bill Brooks billbroo...@yahoo.com Sent: Wednesday, November 2, 2011 9:18 AM Subject: Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses. In either case, the illumination on objects behind the array is a dappled, dynamic light. As Bill says, it's pretty cool from an aesthetic point of view. My personal .02 is that there is no finer place to put an array than a shade structure using clear modules. It keeps everything off the roof, gives shade and makes for a premium installation option. Phil --- When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans. You see, we should utilize natural forces and thus get all of our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy. Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property. There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. -- Thomas Edison -- On Tue, Nov 1, 2011 at 7:48 PM, Keith Cronin electrich...@yahoo.com wrote: Bill Appreciate the feedback. One of the questions that I'm seeking to determine- how much light will filter through the spaces between the cells to the surface below? Lets say for someone that wants to grow orchids- they need low light, as an example. Wondering how much light is diffused through the panels to be able to do things like grow orchids and or have filtered light to work? As an example: Do any of you have irradiance measurements on any carports that have done bifacials and determined how many watts sq m are below? Keith From: Bill Brooks billbroo...@yahoo.com To: 'Keith Cronin' electrich...@yahoo.com; 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Tuesday, November 1, 2011 11:44 AM Subject: RE: [RE-wrenches] Bifacial modules Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. From:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ List sponsored
Re: [RE-wrenches] Bifacial modules
See-thru solar cells have been around for decades. Arco Solar made 4% efficient amorphous silicon modules and car sunroofs in 1984 that were tinted brown like sunglasses. I got a 12-inch square see-thru laminate that still works. I also have a 6.75-inch square sample of MSK Corp's amorphous silicon PV-TV solar panels. They were developed in conjunction with Kaneka and Japanese architects Taiyo Industries. The full-size glass panels, measure 1-meter square. In addition to producing electricity, they provide thermal insulation, solar heat gain protection and protection from ultra violet rays. During the manufacturing process, a laser inscribes a series of ultra fine lines onto the panel to allow 10 percent of visible light to be transmitted through the glass, enough for sufficient light to enter a building even during cloudy conditions while protecting against excessive solar gain. Amorphous silicon solar cells with 10 percent, 5 percent or 1 percent transparency are placed between two sheets of glass to generate power. This solar panel is called PV-TV because it is also used as a display screen on the outside of buildings. See http://www.metropolismag.com/story/20040727/pv-tv-a-multifunctional-eco-friendly-building-material The Tiger Woods Learning Center in Anaheim and other buildings have see-thru Schott solar modules with different amounts of transparency. See http://www.solardesign.com/library/pdf/tiger-woods-solar-curtain-wall.pdf Also, opaque cell solar modules are manufactured with various cell spacings for BIPV applications. I have a Mastech Light Meter LX1010B in my tool kit for measuring lux. This handy tool costs around $20. Joel Davidson - Original Message - From: Keith Cronin To: Phil Undercuffler ; RE-wrenches Sent: Wednesday, November 02, 2011 9:50 PM Subject: Re: [RE-wrenches] Bifacial modules Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith -- From: Phil Undercuffler solarp...@gmail.com To: Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Bill Brooks billbroo...@yahoo.com Sent: Wednesday, November 2, 2011 9:18 AM Subject: Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses. In either case, the illumination on objects behind the array is a dappled, dynamic light. As Bill says, it's pretty cool from an aesthetic point of view. My personal .02 is that there is no finer place to put an array than a shade structure using clear modules. It keeps everything off the roof, gives shade and makes for a premium installation option. Phil --- When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans. You see, we should utilize natural forces and thus get all of our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy. Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property. There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. -- Thomas Edison -- On Tue, Nov 1, 2011 at 7:48 PM, Keith Cronin
Re: [RE-wrenches] Bifacial modules
Geez Joel, we need to start a solar museum for all the cool old stuff you have. I just did a bit of research, and it seems lux is a weighted measure based on visible light present, while irradiation is more a total power measurement. I guess we really need to have two different meters to measure how much light passes through a module. If we were to go a step further and characterize the quality of light present, we might need a spectral analyzer to determine whether its cool white or daylight, etc. As always, the more you think about something, the more complicated it becomes. Ray Walters On 11/3/2011 11:39 AM, Joel Davidson wrote: See-thru solar cells have been around for decades. Arco Solar made 4% efficient amorphous silicon modules and car sunroofs in 1984 that were tinted brown like sunglasses. I got a 12-inch square see-thru laminate that still works. I also have a 6.75-inch square sample of MSK Corp's amorphous silicon PV-TV solar panels. They were developed in conjunction with Kaneka and Japanese architects Taiyo Industries. The full-size glass panels, measure 1-meter square. In addition to producing electricity, they provide thermal insulation, solar heat gain protection and protection from ultra violet rays. During the manufacturing process, a laser inscribes a series of ultra fine lines onto the panel to allow 10 percent of visible light to be transmitted through the glass, enough for sufficient light to enter a building even during cloudy conditions while protecting against excessive solar gain. Amorphous silicon solar cells with 10 percent, 5 percent or 1 percent transparency are placed between two sheets of glass to generate power. This solar panel is called PV-TV because it is also used as a display screen on the outside of buildings. See http://www.metropolismag.com/story/20040727/pv-tv-a-multifunctional-eco-friendly-building-material The Tiger Woods Learning Center in Anaheim and other buildings have see-thru Schott solar modules with different amounts of transparency. See http://www.solardesign.com/library/pdf/tiger-woods-solar-curtain-wall.pdf Also, opaque cell solar modules are manufactured with various cell spacings for BIPV applications. I have a Mastech Light Meter LX1010B in my tool kit for measuring lux. This handy tool costs around $20. Joel Davidson - Original Message - *From:* Keith Cronin mailto:electrich...@yahoo.com *To:* Phil Undercuffler mailto:solarp...@gmail.com ; RE-wrenches mailto:re-wrenches@lists.re-wrenches.org *Sent:* Wednesday, November 02, 2011 9:50 PM *Subject:* Re: [RE-wrenches] Bifacial modules Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith *From:* Phil Undercuffler solarp...@gmail.com *To:* Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org *Cc:* Bill Brooks billbroo...@yahoo.com *Sent:* Wednesday, November 2, 2011 9:18 AM *Subject:* Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses. In either case, the illumination on objects behind the array is a dappled, dynamic light. As Bill says, it's pretty cool from an aesthetic point of view. My personal .02
Re: [RE-wrenches] Bifacial modules
I also like Bill Brooks' test. I use a Daystar irradiance meter to determine light levels through glazing or PV modules by measuring the light throughout the day and at the distance from the glazing and height of whatever is being illuminated. - Original Message - From: Ray Walters To: RE-wrenches Sent: Thursday, November 03, 2011 11:54 AM Subject: Re: [RE-wrenches] Bifacial modules Geez Joel, we need to start a solar museum for all the cool old stuff you have. I just did a bit of research, and it seems lux is a weighted measure based on visible light present, while irradiation is more a total power measurement. I guess we really need to have two different meters to measure how much light passes through a module. If we were to go a step further and characterize the quality of light present, we might need a spectral analyzer to determine whether its cool white or daylight, etc. As always, the more you think about something, the more complicated it becomes. Ray Walters On 11/3/2011 11:39 AM, Joel Davidson wrote: See-thru solar cells have been around for decades. Arco Solar made 4% efficient amorphous silicon modules and car sunroofs in 1984 that were tinted brown like sunglasses. I got a 12-inch square see-thru laminate that still works. I also have a 6.75-inch square sample of MSK Corp's amorphous silicon PV-TV solar panels. They were developed in conjunction with Kaneka and Japanese architects Taiyo Industries. The full-size glass panels, measure 1-meter square. In addition to producing electricity, they provide thermal insulation, solar heat gain protection and protection from ultra violet rays. During the manufacturing process, a laser inscribes a series of ultra fine lines onto the panel to allow 10 percent of visible light to be transmitted through the glass, enough for sufficient light to enter a building even during cloudy conditions while protecting against excessive solar gain. Amorphous silicon solar cells with 10 percent, 5 percent or 1 percent transparency are placed between two sheets of glass to generate power. This solar panel is called PV-TV because it is also used as a display screen on the outside of buildings. See http://www.metropolismag.com/story/20040727/pv-tv-a-multifunctional-eco-friendly-building-material The Tiger Woods Learning Center in Anaheim and other buildings have see-thru Schott solar modules with different amounts of transparency. See http://www.solardesign.com/library/pdf/tiger-woods-solar-curtain-wall.pdf Also, opaque cell solar modules are manufactured with various cell spacings for BIPV applications. I have a Mastech Light Meter LX1010B in my tool kit for measuring lux. This handy tool costs around $20. Joel Davidson - Original Message - From: Keith Cronin To: Phil Undercuffler ; RE-wrenches Sent: Wednesday, November 02, 2011 9:50 PM Subject: Re: [RE-wrenches] Bifacial modules Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith -- From: Phil Undercuffler solarp...@gmail.com To: Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Bill Brooks billbroo...@yahoo.com Sent: Wednesday, November 2, 2011 9:18 AM Subject: Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so
Re: [RE-wrenches] Bifacial modules
Bill Appreciate the feedback. One of the questions that I'm seeking to determine- how much light will filter through the spaces between the cells to the surface below? Lets say for someone that wants to grow orchids- they need low light, as an example. Wondering how much light is diffused through the panels to be able to do things like grow orchids and or have filtered light to work? As an example: Do any of you have irradiance measurements on any carports that have done bifacials and determined how many watts sq m are below? Keith From: Bill Brooks billbroo...@yahoo.com To: 'Keith Cronin' electrich...@yahoo.com; 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Tuesday, November 1, 2011 11:44 AM Subject: RE: [RE-wrenches] Bifacial modules Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. From:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules
Hi Keith, You may be able to accomplish what you are seeking with the Lumos' LSX series frameless modules with the clear backing: http://www.lumossolar.com/products/LSX They let through quite a bit of light. Best, Jeff Keith Cronin wrote: Bill Appreciate the feedback. One of the questions that I'm seeking to determine- how much light will filter through the spaces between the cells to the surface below? Lets say for someone that wants to grow orchids- they need low light, as an example. Wondering how much light is diffused through the panels to be able to do things like grow orchids and or have filtered light to work? As an example: Do any of you have irradiance measurements on any carports that have done bifacials and determined how many watts sq m are below? Keith *From:* Bill Brooks billbroo...@yahoo.com *To:* 'Keith Cronin' electrich...@yahoo.com; 'RE-wrenches' re-wrenches@lists.re-wrenches.org *Sent:* Tuesday, November 1, 2011 11:44 AM *Subject:* RE: [RE-wrenches] Bifacial modules Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. *From:*re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Keith Cronin *Sent:* Tuesday, November 01, 2011 1:04 PM *To:* RE-Wrenches *Subject:* [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules
We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses. In either case, the illumination on objects behind the array is a dappled, dynamic light. As Bill says, it's pretty cool from an aesthetic point of view. My personal .02 is that there is no finer place to put an array than a shade structure using clear modules. It keeps everything off the roof, gives shade and makes for a premium installation option. Phil --- When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans. You see, we should utilize natural forces and thus get all of our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy. Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property. There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. -- Thomas Edison -- On Tue, Nov 1, 2011 at 7:48 PM, Keith Cronin electrich...@yahoo.com wrote: Bill Appreciate the feedback. One of the questions that I'm seeking to determine- how much light will filter through the spaces between the cells to the surface below? Lets say for someone that wants to grow orchids- they need low light, as an example. Wondering how much light is diffused through the panels to be able to do things like grow orchids and or have filtered light to work? As an example: Do any of you have irradiance measurements on any carports that have done bifacials and determined how many watts sq m are below? Keith -- *From:* Bill Brooks billbroo...@yahoo.com *To:* 'Keith Cronin' electrich...@yahoo.com; 'RE-wrenches' re-wrenches@lists.re-wrenches.org *Sent:* Tuesday, November 1, 2011 11:44 AM *Subject:* RE: [RE-wrenches] Bifacial modules Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. *From:* re-wrenches-boun...@lists.re-wrenches.org [mailto: re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Keith Cronin *Sent:* Tuesday, November 01, 2011 1:04 PM *To:* RE-Wrenches *Subject:* [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out
Re: [RE-wrenches] Bifacial modules
For the Sanyo and Silicon Energy modules I've worked with, it is a very small amount of light that actually passes through in the gaps between the cells. You could do a simple ratio calculation by measuring the area of the gaps and the area of the cells. Just guessing, I would say about 3-4%, if that. I wouldn't count on getting much daylight under the array except for what bounces in from underneath. Depending on the height of the array and reflectivity of nearby surfaces, the reflected light under the array can be significant. Hope this helps. -Hans From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules
Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
