Eschew Obfuscation: Solar vs Coal: Who Wins?

Solar vs Coal: Who Wins?

Max Dunn — Tue, 01 Jan 2008 16:09:00 -0800

A new solar power plant just opened up at Nellis Air Force Base in southern Nevada [1]. Currently it is the largest solar photovoltaic system in North America with a capability of 14 megawatts (mW) of peak power, and producing about 25 million kilowatt-hours (kWh) of electricity per year [2].

However, it cost $100 million to build, which is about $7,000 per kilowatt (kW). This is a lot more than a coal-powered plants which costs about $3,000 per kW to build [3]. But since the sun is free and coal-powered plants have to pay for the coal, shouldn’t this make up for the additional cost of solar systems?

It turns out, that it doesn’t. To see why, let’s look at the numbers.

"Solar vs Coal: Who Wins?" by Max Dunn

Tue, 22 Apr 2008 18:07:51 -0700

Another way of looking at this is that solar only needs to come down to $2,500 per kW in order to be competitive with coal. Since some thin-film solar cells are approaching $1,000kW, it shouldn’t be long before complete solar plants will be cheaper than coal.

"Solar vs Coal: Who Wins?" by Max Dunn

Tue, 01 Jan 2008 17:36:33 -0800

If coal had to cleanup its emissions, it would likely double the cost of its power. Then solar would have a much better chance of being able to compete. However, telling almost everyone in the world (including everyone in the Third World) that they are going to pay double for electricity probably wouldn’t go over very well.

"Solar vs Coal: Who Wins?" by Max Dunn

Tue, 01 Jan 2008 17:29:34 -0800

I was using 25M kWh/yr (as from reference #2) and rounded up, which accounts for part of the difference in our costs for solar power. However, the biggest difference is that I used a 30-year lifetime while you used a 40-year lifetime. Do you have any references to support a 40-year lifetime for solar panels?

"Solar vs Coal: Who Wins?" by J.R.

Tue, 01 Jan 2008 17:14:24 -0800

Very interesting analysis. Here’s a slightly different calculation, however. If the solar plant generates 30M kWh/yr (from your footnote 1) and lasts for 40 years (my #), then it will produce 1200M kWh over it’s lifetime. Since it cost $100M to build, isn’t that 12kWhr per dollar, or $0.083/kWh? That’s pretty damn close to the cost of coal! Now consider the cost of exhaust scrubbers and labor costs to run a coal plant. Solar’s a pretty clear winner now don’t you think?