Luck needed to avoid summer blackouts

California's on-again, off-again predictions of a summer power crisis are on-again:

Keepers of the state's power grid say supplies are stretched so thinly that a widespread heat wave or wildfire could mean homeowners and businesses may once again wait their turn for the lights to go out.

Rolling blackouts -- planned power outages that are "rolled" from area to area to protect the power grid when electricity supplies are critically low -- became part of Californians' life during the state's power crisis four years ago.

Explosive growth in areas far from cooling ocean breezes means such outages will be increasingly likely unless the state boosts supplies with more power plants and transmission lines and better efforts to use power wisely.

Financial and political uncertainties following California's 2001 energy crisis slowed efforts to build new power plants as antiquated power plants go off-line.

Since then, the state's population and economy have continued to expand.