One problem is that the wind usually refuses to blow hardest at times of peak demand for electricity, generating only about 7.5 megawatts per 50 MW of nameplate capacity at peak. The 1,731 installed megawatts have killed some 10,000 birds. On a percentage basis, windmills at Altamont Pass kill eight times as many bald eagles as the Valdez oil spill every year. Another favorite, solar power, while coming down in price from around 25 per kWh to a claimed 8 cents due to improved photovoltaic cells, still costs three times as much as new gas-generated capacity. The often-ignored externalities are also substantial.
Solar plants are also bird killers.
Bird deaths per megawatt at Solar One operated by Southern California Edison, primarily due to collisions with mirror-like surfaces, were 10 times as high as at Altamont Pass. The installation of the Kramer Junction Luz site killed numerous desert tortoises and ground squirrels as they were displaced from their natural habitat. Hydropower, long a favorite of renewable energy buffs, has fallen from favor. Geothermal is not a renewable resource. But the most important externality of negawatts is the effect on human life.