Shasta Power Output Down 1/3 w. Reservoir Down 1/2; Expect 20% Power @ Other Dams
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In the 1950s, hydropower supplied almost 60% of the state's electricity. Now, it provides 14% to 19% in a normal year, and even less during a drought — accounting for about 8% of the state's total power last year. Renewable energy, on the other hand, provided more than 20%, according to the California Energy Commission.
Making up the difference from less hydropower has not been cheap. The cost to California ratepayers could have been as high as $1.4 billion from 2012 through 2014, according to a report by the Pacific Institute. Renewable energy, especially solar, helped make up for about 55% of the reduction in hydroelectricity in 2013 and 2014, state officials said. Natural-gas-fired power made up the rest.
Burning more natural gas to compensate for the reduced hydropower led to an 8% increase in carbon dioxide emissions from California power plants during a three year period, said Gleick, author of the Pacific Institute study. Hydropower produces little to no air pollution. "If the drought continues," Gleick said, "if one of the impacts is a permanent reduction in hydropower, we need to ramp up other renewables even more than we are."
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Experts said California had little choice but to diversify its power generation beyond dams. Even in normal years, the dams have been producing basically the same amount of hydropower as they did decades ago. Huge population growth since the 1950s meant the need for more overall electricity. Instead of building more dams to supply the extra electricity, officials found other sources of energy. "We've built on all of the good dam sites in California. We're not going to expand hydrogeneration almost anywhere in the West," Gleick said. "So in an expanding energy demand situation, hydro just becomes a smaller and smaller fraction of the overall system."
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http://www.latimes.com/local/california/la-me-drought-hydro-20150517-story.html#page=1