Meanwhile, it also could save between 400 to 1,000 megawatts of electricity. Put in perspective, that is enough energy for 300,000 to 750,000 homes, or the equivalent of instantly creating one or two new power plants. Last Friday, Edison tested the idea by turning down the voltage 4 percent, to about 117 volts, at a substation in Riverside County, for 15 minutes. It received no consumer complaints and reduced power demand about 2 percent, he said. Edison can make the change by radio control.
Some experts are wary about potential pitfalls.
Home appliances, computers and other equipment are normally rated to run best at about 115 volts. If voltage is dropped too low, say below 110 volts, it can damage appliances by overheating motors. In 1978, during a previous energy crisis, Ajello helped write the rule that set the operating range for California's grid at between 114 and 120 volts. Back then, the state saved energy by reducing the top range, which was 126 volts. The change reduced energy consumption in California 3 to 5 percent, a savings of about 4 million barrels of oil a year, according to trade journals of the time.