“Real” prices? That’s hard to evaluate, because if there are any example calculations on the site, they’re very hard to find.

Assuming the “2000-watt” $17,000 only produces 1000 watts for only 8 hours a day for 20 years,

$17 000 / (8 * 365 * 20) = $0.29 per KWh

… even that conservative estimate prices out less than their “sunny climate” figure of 35 cents. Also: a $400 price drop for the $17,000 system in one suggests that before long you could have twice the capacity for half the price.

So what does the word “real” mean?

By real, I just mean that if I went out and tried to buy a solar system from one of a variety of suppliers, what’s the average price that I’d pay?

Your point is well-taken that changing some of the assumptions changes the long-term price of the system. This site, though, seems most interesting for its tracking of upfront costs.

And as for price drops suggesting that “before long you could have twice the capacity for half the price,” coming down the cost curve, as people say, is a lot more complicated than that. I agree that it’s basically impossible to calculate the “real” cost of a system in 10 years (or what have you). But that’s precisely why I’m interested in the cost, right this month, of a system for someone trying to buy one. It’s the closest we’ve got to a real price and much better than taking First Solar’s numbers and projecting decreases from there.