When it comes to solar power, the standard definition of efficiency isn’t necessarily the most useful:
As the world’s lowest-cost maker of solar panels, First Solar, which is based in Arizona, is well-placed to cash in. Spurning crystalline silicon, the main ingredient in most solar panels, it uses another sort of semiconductor, cadmium telluride, a product of mining waste which it deposits onto glass at high temperature.
The “thin film” photovoltaic cells this produces are relatively inefficient at converting solar radiation into electricity. First Solar’s panels have an average efficiency rate of 11-12% as opposed to 14-15% for the silicon ones.
Yet they are cheap, costing around 74 cents per watt of generating capacity, compared to well over a dollar for the cheapest silicon panel. And they are getting better, with over 17% efficiency achieved in lab conditions. They also perform well at high temperatures and through dust — making them suitable for deployment out West.
It never ceases to amaze me how long it takes these firms to think of challenging their assumptions. I really, really hope some solar engineer just facepalmed so hard they fell unconscious, for not thinking of testing that mining waste.