San Diego Gas & Electric officials said Thursday that they expect to be able to meet power demands this summer despite losing supply from the nuclear plant in San Onofre, which is offline due to wear in tubes that carry radioactive water.

Utility spokeswoman Allison Zaragoza said the situation will be helped by a new transmission line called Sunrise Powerlink, which is expected to bring power from the Imperial Valley and go online any day.

San Onofre has been shut down for four months. It typically produces enough electricity for about 1.4 million homes.

SDG&E President Michael R. Niggli said San Onofre, which is the region's largest power plant, will remain offline for most of the summer.

Zaragoza warned that conservation will still be key to ensuring the lights stay on, particularly in the event that there is an extended heat wave.

"If the situation is tight and we don't get enough conservation from customers, that is always difficult," said Zaragoza.

The agency that manages much of the state's power grid, the California Independent System Operator Corporation, said in its summer assessment that there were adequate supplies for most of California. In the second half of 2011, more than 283 megawatts of new power were added to the grid and an estimated 926 megawatts are coming on line by July 1, 2012, according to the agency.

Much of the power is from renewable generation, such as solar and wind.