The U.S. Energy Department's Energy Information Administration states San Diego Gas and Electric activated a $1.9 billion transmission line. The Sunrise Powerlink Transmission project adds 800 megawatts of power capacity to the Southern California grid. It could be ramped up to 1,000 MW, the agency said.
The regional power grid was expected to suffer from a capacity shortage because of unplanned outages at a nuclear power station near San Diego.
The EIA states the region has significant renewable energy potential. The line connects to two solar power projects that are under construction in the area.
The three main utility companies in the state -- Pacific Gas & Electric Co., San Diego Gas & Electric Co. and Southern California Edison -- are required to secure at least 20 percent of their resources from renewable energy.
The EIA said transmission capability is critical for the state's grid as it imports "significant supplies" of electricity from other regions.