A friend at work mentioned a few days ago that he was interested in getting some solar panels. He's already taken a few steps to make his family more self-sufficient and less reliant on public utilities, and this is the next step.
I began to wonder what kind of money solar panels were going for. So I hit up my trusty source: eBay.
I did a search for “solar panels” and checked the completed listings for items that sold. I sorted from highest total price (final bid price plus shipping) to lowest. Here's what sold on the first 400 listings last night:
This is a very rough calculation, of course. I took new and used, monocrystalline and polycrystalline, with and without extra stuff, with cracks and without, all different brands, and just took the total cost and divided it by the total wattage to get the cost per watt. The average of the 84 auctions: $3.59 per watt.
How fast do solar panels pay for themselves? To figure this out we need to know how much electricity would cost elsewhere. For us, it's 9 cents per kilowatt-hour. Let's say that my power needs are 1 kw, 12 hours per day. One kilowatt of solar panels will cost me $3,590, plus installation, which I have no clue, but let's say that it brings up the cost to $5,000. So, there I go, I've paid for my power needs.
If I pay 9 cents per kilowatt-hour, that's $1.08 per 12 hours (day). Diving this into $5,000 gives me a payback time between 12 and 13 years. It's a pretty expensive alternative at those prices. Plus, I'm not even looking at power losses, cloudy days, tree shade, aging of the panels, etc. It's likely a better deal for people in sunnier states (and higher metered energy prices).
But on the other side of the equation, will power prices go up? Will it be rationed? Will it even be available? This gets back to my friend's original motivation: self-sufficiency. In any case, this is something to keep on the radar.
My analysis might use a little fine-tuning. Any other things that are important to consider?