I covered before how I strongly recommend against building your own homemade solar cells. If you’re not building the cells yourself, you’ll either have to find them (unlikely, unless you have a friend at Evergreen Solar), or buy them (much easier). There are a couple places you could look to buy cheap solar cells – you could go to your local hardware store, or you could check with highway patrol to see if they’ve picked up any solar panels destroyed in car accidents lately.
Those are both possibilities, but the best way to buy cheap solar cells is through eBay – and here’s how you do it:
1. Search eBay for “broken solar cells” or “chipped solar cells” – this should give lots of auction results.
2. Try to find cells that have not been damaged too badly and that are relatively the same size – this will make it far easier to assemble everything onto one panel and figure out how many you need to buy.
3. If you want to go for a higher-priced option, you could look for transparent cells on eBay, or find newly produced cells by large companies like Evergreen Solar. This is a more expensive option, but it will make it easier to calculate your expected power output and get the right number of cells.
How much should you expect to pay?
That depends on what condition the cheap solar cells are in when you get them off eBay, but if you do it the way we recommended above, you should pay no more than a few cents for each individual cell. 100% functional or professionally-produced cells like those from Evergreen Solar will be more expensive, of course – but you should still not pay more than ten cents or so per cell.
In all likelihood, the shipping costs for the cells will be your highest expense – you might pay upwards of $20 for that, depending on where the seller is located relative to you and the shipping method. Just doing some quick math here, you might expect to spend around $30-$50 for 500 chipped solar cells on eBay – probably not enough to completely eliminate your electric bill, but enough to substantially reduce it and save you thousands of dollars each year.