By Steve Gorman LOS ANGELES (Reuters) – California regulators on Wednesday adopted the nation's first mandatory energy efficiency rules for computers and monitors – devices that account for 3 percent of home electric bills and 7 percent of commercial power costs in the state. The state Energy Commission said that when fully implemented the industry-backed plan will save consumers $373 million a year and conserve at least as much electricity annually as it takes to power all of San Francisco's households. Final approval at a meeting of the five-member commission in Sacramento capped several years spent developing the rules in collaboration with computer makers, consumer activists, the Natural Resources Defense Council (NRDC) and other environmental groups.