Perhaps it is a commentary on the standards of contemporary journalism that it was difficult to distinguish between Keller's article (How useful are wind-energy plants? 8/4/06) and a wind developer's marketing brochure. The short answer is not very. Comparing wind power to conventional hydro power is specious. Hydro power is available when it isn't raining. That's what dams are for. Wind energy isn't controllable. More to the point: wind energy's achilles' heel-its intermittency- limits its capacity value and its impact on emissions.