Sun, wind and drain
As the years go by, bumper sticker (“spin, baby, spin”) enthusiasts of wind power must be scratching their heads about a Vinalhaven turbine project that hasn’t lowered electricity costs. One would hope that reasonable people would consider reasonable evidence like comparing electricity bills. But beyond the bills, even if you don’t mind paying more for wind power, shouldn’t you care whether wind power is reducing carbon emissions or whether supporting wind power is ever going to amount to a solution to the energy crisis?
From the point of view of the neighbors of the wind turbines — who have been objecting for years to the noise exceeding state limits — it is upsetting (putting it mildly) that benefits of wind power as promised don’t exist. Real property, natural quiet and health have been sacrificed for other people’s enthusiasms. Those enthusiasms might be self-satisfying but they don’t have much to do with reality as the Economist points out in the following excellent report:
Wind and solar power are even more expensive than is commonly thought
The Economist, Jul 26th 2014 | From the print edition
SUBSIDIES for renewable energy are one of the most contested areas of public policy. Billions are spent nursing the infant solar- and wind-power industries in the hope that they will one day undercut fossil fuels and drastically reduce the amount of carbon dioxide being put into the atmosphere. The idea seems to be working. Photovoltaic panels have halved in price since 2008 and the capital cost of a solar-power plant—of which panels account for slightly under half—fell by 22% in 2010-13. In a few sunny places, solar power is providing electricity to the grid as cheaply as conventional coal- or gas-fired power plants.
But whereas the cost of a solar panel is easy to calculate, the cost of electricity is harder to assess. It depends not only on the fuel used, but also on the cost of capital (power plants take years to build and last for decades), how much of the time a plant operates, and whether it generates power at times of peak demand. To take account of all this, economists use “levelised costs”—the net present value of all costs (capital and operating) of a generating unit over its life cycle, divided by the number of megawatt-hours of electricity it is expected to supply.
The trouble, as Paul Joskow of the Massachusetts Institute of Technology has pointed out, is that levelised costs do not take account of the costs of intermittency.* Wind power is not generated on a calm day, nor solar power at night, so conventional power plants must be kept on standby—but are not included in the levelised cost of renewables. Electricity demand also varies during the day in ways that the supply from wind and solar generation may not match, so even if renewable forms of energy have the same levelised cost as conventional ones, the value of the power they produce may be lower. In short, levelised costs are poor at comparing different forms of power generation. Read the rest of this entry »