But they'll pollute more because they'll run more often to compensate for the loss of electricity that California normally would have imported from out of state. A drop in hydroelectric power from the Pacific Northwest and the faltering credit of investor-owned utilities have been blamed for the shortfall. The increases might not add noticeably to hazy skylines because power plants have been responsible for only about 3 percent of the oxides of nitrogen in the state's air. Vehicles account for more than half. But the emissions are a setback for state and regional agencies that have prided themselves on blazing a pollution-fighting trail for the nation.
Oxides of nitrogen are a key component of smog, which causes and aggravates breathing problems.
Diesel engines, a major producer of that pollutant and toxic soot, are increasingly being enlisted as stopgap power-providers amid forecasts of a summer filled with temporary outages. But there likely are hundreds more generators popping up. Applications are required only when a generator would be near a school or power plant. The plants will run during times of peak energy use. Those natural gas plants ultimately will have to use the least-polluting technology but don't have to do so in the short term.