Let’s say that you really, really don’t like coal. How much would it cost to install a number of windmills sufficient to produce the energy that the U.S. currently generates from coal?
Cost per MW
According to some random guy on the Internet, “[m]ost of the commercial-scale turbines installed today are 2 MW in size and cost roughly $3.5 Million installed”.
The amount of energy produced by a wind generator depends on, well, the wind. A “capacity factor” must therefore be applied to the generator’s nameplate capacity before actual energy output can be estimated. A figure of 33% seems reasonable, and will be used for the purposes of this discussion.
The U.S. generated 153,388 GWh of energy from coal in February 2010. To generate 153,388 GWh over the 672 hours of February 2010 would require 692 GW (692,000 MW) of new nameplate capacity, at a cost of 1.2 Trillion dollars. (Since wind turbines last about 20 years, this should not be mistaken for a one-time cost.)
I actually think the $1.2 Trillion figure is unrealistically low, because it (a.) ignores the cost of building new transmission, (b.) assumes that good (cheap!) sites could be found for 346,000 new windmills in the U.S., and (c.) assumes that marginal costs will remain constant. But let’s run with it for now.
People sometimes speak of a “Manhattan project” for “green” energy. The actual Manhattan project cost about $1.8 Billion though October 1945. U.S. GDP in 1945 was $223 Billion, so the Manhattan project cost 0.8% of U.S. GDP (spread, naturally, over several years). By comparison, a $1.2 Trillion expenditure would represent 8.2% of U.S. 2010 GDP, estimated at $14.6 Trillion. That’s a full order of magnitude greater.