On 31/05/2007, at 10:43 AM, gary dorn wrote:
Sorry to go off-topic here, although there is a computer-related
issue at the end of all this.
I'm hoping WAMUG members may have some information and/or
experience with installing and using individual residence
renewable grid-connected power systems. I'm looking at putting the
largest solar array I can afford on our roof (4 or 5 kW) to both
supply our own electricity needs and sell back excess to the SW
grid when the sun is shining, and purchase energy as needed when
the sun is not out/at night.
Fantastic amount of information Garry , Mike , Tony .
Can I add just a little :
If I may.
PV/Wind firstly power systems have been installed allover WA/
Australia for the last 20 odd years and has proven to be effective
means of obtain sun driven quality power.
There are 4 types of systems you can install
stand alone - a complete system of: pv+ wind. regulator,
batteries, inverter, controller & distribution board -
grid connected - a power system - Pv + wind, regulator, in/out
inverter, distribution board, meter
hybrid - PV + wind, regulator, batteries, inverter, controller,
distribution board, meter
grid switched - PV + wind, regulator, batteries, inverter,
controller, distribution board with switches, meter
they are generally similar but operating in a different ways
Standalone as it says is all power is consumed from the batteries
via the 12/24v- 240 v inverter - you need enough battery storage to
last 5- 10 days of use. All energy is generated by a PV + wind
system.
like here http://web.mac.com/dornworks/iWeb/
OrganicSolarArchitecture/Built/9274EFED-48D6-4FD9-
BA69-1186A284FB4D.html
grid connected as you have mentioned mains in/mains out with a
sizeable specialised inverter, the power you generate has to be the
same quality as the mains - check your mains is 240v - some peoples
are 440v -
The 440 volts mentioned here is actually 3 single 240v phases ...
without explaining why ,
if you measure between any 2 phases the sum of the voltages will be
440v .
In residential use the 3 phases are only used together very
occasionally , mostly only on
electric motors . eg: reticulation bore pump , and some electric hot
water heaters.
At other times the 3 phases are used individually and separately to
distribute the load.
Now as to the load and use of the Power :
In my case in a passive solar house :
Refrigerator & Electric oven drags the most power . Have no need
for an air conditioner .
For a cheap Inverter supply . Lights would be no problem.
BUT ,
the same cheap Inverter feed has POTENTIAL to introduce Noise and
hash into entertainment units ,
and create havoc with anything Computer .
If you wish to avoid that potential I would recommend
an Inverter unit that meets Mains Power quality standards.
Bob
this inverter can be quite expensive. In my opinion Synergy ought
to pay for this - but fat chance on that .
You are at the mercy of main power fluctuations. If you want
consistent quality power, an additional battery bank may need to be
considered to weather the mains fluctuations ( ie blackouts /
brownouts).
Hybrid, is where you have 2 separate un-connected systems,
A -is mains in for high energy items such as fridge, air con,
electric heaters, washers etc
B- is PV +wind powered small stand alone system, running tv ,
radio, computer, lights
this system can be a good way to start and can reduce the cost
significantly.
grid switched - the latest idea whereby you have a standalone PV
system with mains backup, and a switch changes over when the
batteries get low, this allows the system to start off small and be
enlarged over time if you wish. It also eliminates the grid
inverter which can be quite pricey.
With all systems it is worth considering wiring the building into
different circuits of priority, so that essential fixtures will not
be harmed as the cutting out of other non essential systems can
alarm you to lower power supply levels etc
Consider the Unisolar Amorphous triple junction cell panels, they
can be roof integrated and have a better power rating at high
summer temperatures, and are less prone to storm damage and not
charging in cloudy weather ( ie shade tolerant).
My solar engineer, has written a book about all this stuff -SOLAR
TECHNOLOGY DESIGNERS CATELOGUE 169 paged for $150, ( I have a
couple of books if you would like one) he also has developed a
series of off the shelf systems titled, planet suite and solar
"micro" systems which you may like to investigate.
he also developed the Grid switched systems
see http://www.unisun.com.au/planetsuite
hope this helps
--
Gary Dorn
Permaculture architect
<[EMAIL PROTECTED]>
Perth, Western Australia, Australia
integrating Permaculture , Organic Solar architecture,
Straw bale construction & Solar and wind power systems
http://web.mac.com/dornworks/iWeb/HOME/Dornworks.html
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