As part of its effort to promote renewable energy, UC San Diego will gradually reduce the amount of electricity it purchases from San Diego Gas & Electric Co. and replace it with “green” power produced from fuel cells and solar sources on campus.

The university currently buys about 15 percent of its energy from SDG&E for 13 cents per kilowatt hour. The rest of the power comes from the cogeneration plant that houses a pair of jet engines that run on natural gas.

Within the next year and a half, the university plans to generate 7.4 megawatts from renewable energy sources — 3 megawatts of off-peak electricity purchased from Southern California wind farms; 2.4 megawatts from a pair of large fuel cells that run on methane gas recaptured from the Point Loma Wastewater Treatment Plant; and 2 megawatts from photovoltaic solar arrays set atop 26 campus buildings — says Gary Matthews, UCSD vice chancellor for resource management and planning.

The primary reason for the change, which may result in cheaper electricity bills, is to reduce the school’s greenhouse gas emissions, university officials say.

The 1,200-acre campus’s laboratories, hospital and intensive research efforts create a large appetite for energy, which peaks at 38 to 40 megawatts, underscoring the need for active conservation.

The university, which has 27,500 students and 26,000 employees, is negotiating contracts to buy energy from third-party vendors that will build the photovoltaic arrays and fuel cells and place them on campus. The school says it will not pay for any of the equipment, but purchase energy from the vendors on par with SDG&E rates.

The 7.4 megawatts is enough energy to power 2,100 homes for a year and keep 10,000 tons of carbon dioxide, or CO2, from entering the atmosphere, university officials say.

“Our changing climate, and especially global warming, is a growing problem that needs to be addressed now,” said UCSD Chancellor Marye Anne Fox at a recent news conference touting energy conservation.

Living Laboratory

UCSD, which is the home of the Scripps Institution of Oceanography in La Jolla, is a living laboratory for climate solutions, administrators say.

It’s the site where the Keeling Curve was pioneered 50 years ago that identified man’s influence on global climate. University and Scripps researchers work on the science behind global climate change, so it makes sense that the physical operation of the campus be a model of fixing damage to the atmosphere, says Tony Haymet, vice chancellor of the Scripps Institution of Oceanography.

“The important point from my point of view is that while we’re out there campaigning to measure ocean acidity as CO2 dissolves in the ocean and monitoring every increasing emission of CO2, it’s important that someone has our back when someone asks, ‘What are you actually doing to lower emissions?’ ” he said.

“We’re lucky to have our physical plant guys walk the walk,” he said.