Stanford University is building a new energy system that incorporates solar power with heat recovery. The new system, called the Stanford Energy System Innovations (SESI), will save the university $420 million in energy costs over 35 years, making Stanford one of the most energy-efficient research universities in the world.
The university has also committed to providing the majority of its campus electricity from renewable sources within California. The university will get half of its electricity from a 68 MW solar generating station designed and built by SunPower. The Stanford Solar station will include more than 150,000 SunPower solar panels installed on about 300 acres in California. It is expected to come online in late 2016.
Stanford has also selected SunPower to install about 5 MW of rooftop solar systems on campus. Together with the Stanford Solar plant, the solar systems will provide about 53 percent of Stanford’s total electricity use. The remaining 47 percent of Stanford’s electricity will come from the California grid, resulting in another 12 percent of renewable power.
The renewable energy is joined by a first-of-its-kind campus heat recovery system, which began operating in March to heat and cool campus buildings. The new, on-campus Central Energy Facility (CEF) relies on a heat-recovery process that is 70 percent more efficient than the cogeneration process Stanford had used since 1987. The CEF will meet more than 90 percent of campus heating demands by capturing almost two-thirds of the waste heat generated by the campus cooling system to produce hot water for the heating system. To make the exchange possible, Stanford replaced 22 miles of underground pipes and retrofitted 155 buildings to convert the campus from a steam- to hot-water-based system.
The CEF is run by a patented “model-predictive-control” software system developed at Stanford that optimizes cost and energy efficiency. The software continuously monitors plant equipment, predicts campus energy loads and grid electricity prices, and steers the system to optimal efficiency. It also continuously reviews its own performance.
Key partners in building the SESI plant include Whiting-Turner, Affiliated Engineers, ZGF Architects, Johnson Controls and Siemens.
Photo of Stanford University via Shutterstock.