Green energy update

The New York Times:

“We’d love to tell you that solar power is as economic as fossil fuels, but the reality is that it is not,” Lewis Hay III, FPL’s chairman and chief executive, said on a recent tour of the plant.

...Part of the challenge in increasing the share of renewable energy sources is to make up for their variable nature — at night, for example, or when the wind does not blow. Because electricity cannot be stored easily, utilities must always produce enough power to meet electric demand at any given time. In practice, this means they need keep a lot of idle plants that can be fired up rapidly when demand spikes.

About 20 percent of the generation capacity overseen by PJM Interconnection, a regional transmission operator covering 13 northeastern and mid-Atlantic states, is used less than 100 hours a year, according to Lester B. Lave, a professor of economics at Carnegie Mellon’s school of business.

“As long as the contribution of wind and solar is very small, utilities can handle it very well,” Mr. Lave said. But what happens once the share of renewable power rises to 10 percent? Or 20 percent? “No one knows what the magic number is.”

Spain, which generates more than 12 percent of its electricity from wind, has struggled with wind variability, Mr. Lave said. Similar problems are also cropping up in the United States, especially in states where solar and wind power are on the rise. In 2008, for example, Texas narrowly avoided a blackout when wind power, which supplied 5 percent of demand at the time, experienced an unexpected lull, driving wind electricity generation down to 350 megawatts, from 2,000 megawatts, in less than four hours, according to Mr. Lave.

The scale of problems encountered by this industry is only matched by the certainty on the part of certain politicians that it represents a future significant source of economic growth.