DIY Solar Panels

I've been reading around the 'net and found there is a bit of a buzz around building your own solar panels. I've always liked the idea of producing my own electricity and with the amount of solar radiation arriving on our roof everyday it should be quite practical. Only the financial cost has stopped me so far. For a reasonable sized, grid tied, system I’d be looking at well in excess of $NZ10,000.

One possible solution is to make my own photovoltaic panels. I’ve ordered 200 broken solar cells from a seller on e-bay. They cost me $NZ120, with over half that cost being shipping from Miami. I estimate each cell should give me, at worst, about 0.6W which should give me about (0.6 * 180) 108W. I’m using 180 to allow for some unusable cells and some mistakes. This works out at about $1/Watt. Add to that some building materials to bring the cost up to $1.50/Watt which is about 20% of the cost of buying the cheapest professionally made panels and 10% the cost of the more expensive ones. I’m expecting to get better than 108W, but I’ll keep my estimates low so I’m not disappointed.

Of course, my panels won’t come with a 25 year output guarantee, but I’ll take the risk.

After my paypal payment cleared the shipper sent the package, 5 days later it would have been at my door but we were away, camping at Okains Bay. I suppose I’ll have to wait until tomorrow, which is just as well as I’ve got unpacking to do.

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Shipment Activity Location Date & Time
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Attempted Delivery NEW ZEALAND 01/16/10 1:20pm
Out of Foreign Customs NEW ZEALAND 01/15/10 4:59pm
Arrived Abroad NEW ZEALAND 01/15/10 1:20pm
International Dispatch UNITED STATES 01/12/10 4:44pm
Arrival UNITED STATES 01/12/10 4:43pm
Electronic Shipping POMPANO BEACH FL 33077 01/11/10 1:09am

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We use about 8000KWh (kilowatt hours) a year. If we assume that 60% of that is for hot water (4800KWh) and that a solar + gas hot water system would supply all we need that leaves us with 3200KWh. If we put gas in for hot water we would probably cook on that as well, removing our electric stove, but I'm ignoring that for the moment).

3200KWh / 365 (days in a year) is just under 9KWh/day. Assuming 4 hours of usable sun a day that would mean I'd need a 2.25KW solar array to supply our needs.

There are a lot of assumptions in there and factors I'm ignoring (like storage, dark winter weeks, peak loads etc) but that gives a rough indication of the size of array I'd need.

At $1.50/Watt I'd need to spend $3375 on the panels, which is not a lot of money when compared with using professionally built panels. I'm not sure I'll ever get there but there's the target.