The best wind-energy facilities can generate electricity at costs comparable to those of large coal- and nuclear-powered plants. However, compared with these old workhorse plants, wind-powered generators are less reliable because they depend on, well, the wind.
According to a team of energy analysts led by Paul Denholm of the National Renewable Energy Laboratory in Golden, Colo., wind systems' reliability could be boosted if they saved up excess energy during strong breezes. Such energy-storage systems could deliver full electric power about 80 percent of the time, which is comparable to the performance of conventional power plants, the researchers say. The challenge is how to store the energy economically.