No kidding.

Via the Economist

…Charles Frank of the Brookings Institution, a think-tank, uses a cost-benefit analysis to rank various forms of energy.

…To determine the overall cost or benefit, though, the cost of the fossil-fuel plants that have to be kept hanging around for the times when solar and wind plants stand idle must also be factored in. Mr Frank calls these “avoided capacity costs”—costs that would not have been incurred had the green-energy plants not been built. Thus a 1MW wind farm running at about 25% of capacity can replace only about 0.23MW of a coal plant running at 90% of capacity. Solar farms run at only about 15% of capacity, so they can replace even less. Seven solar plants or four wind farms would thus be needed to produce the same amount of electricity over time as a similar-sized coal-fired plant. And all that extra solar and wind capacity is expensive.

If all the costs and benefits are totted up using Mr Frank’s calculation, solar power is by far the most expensive way of reducing carbon emissions. It costs $189,000to replace 1MW per year of power from coal. Wind is the next most expensive. Hydropower provides a modest net benefit. But the most cost-effective zero-emission technology is nuclear power. The pattern is similar if 1MW of gas-fired capacity is displaced instead of coal. And all this assumes a carbon price of $50 a tonne. Using actual carbon prices (below $10 in Europe) makes solar and wind look even worse. The carbon price would have to rise to $185 a tonne before solar power shows a net benefit.

There are, of course, all sorts of reasons to choose one form of energy over another, including emissions of pollutants other than CO₂ and fear of nuclear accidents. Mr Frank does not look at these. Still, his findings have profound policy implications. At the moment, most rich countries and China subsidise solar and wind power to help stem climate change. Yet this is the most expensive way of reducing greenhouse-gas emissions. Meanwhile Germany and Japan, among others, are mothballing nuclear plants, which (in terms of carbon abatement) are cheaper. The implication of Mr Frank’s research is clear: governments should target emissions reductions from any source rather than focus on boosting certain kinds of renewable energy.