Stanford is partnering with SunPower to make the campus energy supply greener by installing new rooftop photovoltaic (PV) systems, or solar panels, and building an off-campus solar energy plant. The project is a part of the Stanford Energy Systems Innovations (SESI) project, an effort to reduce the university’s greenhouse gas emissions.

“There is an important context for this,” said Scott Gould, Senior Engineer for Building Energy Systems Commissioning. “[The project] fits in with this larger puzzle of how we use and produce energy on campus.”

Along with the new PV systems and the solar farm, called the Stanford Solar Generating Station, SESI installed the new Central Energy Facility (CEF) to meet most of the campus’s heating demands. The university now uses electricity to produce chilled water and relies on a new electric heat recovery system to create hot water. This shift in energy use created the opportunity to introduce more solar production as well.

SESI’s implementation meant shutting down the now-obsolete cogeneration plant across from Stanford Hospital, which previously supplied almost all of the university’s energy. Because the cogeneration plant ran on natural gas, the university previously relied entirely on fossil fuels for power. When SESI installation and construction is finished before the end of 2016, renewable energy will supply 65 percent of all campus electricity, and 53 percent will come from the solar plant and the new panel installations on campus.

Charlie Jiang ’16, co-president of Students for a Sustainable Stanford (SSS), is glad to see the university take on a project like SESI.

“I applaud Stanford for doing its part to fight climate change and make this campus more sustainable,” he wrote in an email to The Daily.

The project is not Stanford’s first venture into solar energy. The first solar panels on campus, installed in 2002, included a small system at Synergy House and a system at Jasper Ridge Biological Preserve. In 2004, Stanford installed a larger solar system at the Dish.

The current campus PV systems, including the recent installation at Knight Management Center, total 672 kilowatts (kW). The new rooftop PV system will add 5,500 kW of power, and the Stanford Solar Generating Station will contribute another 68,000 kW. For comparison, a typical home PV system is about 3 to 5 kW.

According to Gould, a steep decline in the price of solar modules has been a defining factor in choosing to implement this project now. He noted that energy officials on campus have been looking to enact a project such as SESI, but it has been too expensive in the past, especially since Stanford is a not-for-profit university.

“Modules have become more of a commodity,” Gould said. “The price has come down by half [since 2004]. That’s been one of the things that’s pushed us in this direction.”

In addition to the cost changes, Gould credits campus perception of solar energy with the feasibility of SESI today. Stanford recently installed more PV systems on campus, particularly in the Science and Engineering Quad on buildings including Y2E2 and the Huang Engineering Center. Gould says PV installation on these buildings has sparked greater interest at Stanford in expanding solar energy production.

“When you have these high-profile buildings on campus [using PV systems], it’s sort of hard for the rest of the campus to say, ‘We don’t want that,’” he said.

Stanford selected SunPower, a San Jose-based solar technology company, as a partner for the project from an initial group of about 20 companies. The company was founded by former Stanford professor and alum Richard Swanson, a major solar industry figure. Swanson developed the technology used in SunPower’s solar modules in Stanford labs and left the university to found the company.

While he is happy to be working with a company with Stanford roots, Gould says that links to the university were not a prerequisite for partnership.

“It was just lucky happenstance,” he said. “And I think that because they have Stanford origins, they’d like to see the project be successful.”

SunPower Vice President Billy Kelly expressed excitement to be working with Stanford on this project.

“Universities and large organizations are rethinking how they energize their operations, and [they] want to invest in renewable energy at scale,” he said. “We applaud Stanford’s leadership and the exciting steps they are taking to convert their energy to electricity, which allows for the potential to entirely energize operations with renewable energy.”

Before partnering with SunPower, project managers met with a campus architect, who helped choose which buildings on top of which to install PV systems. The team selected 18 buildings across campus, a decision involving many factors from historic to structural to aesthetic. Gould noted that a good candidate must have a good roof profile and relatively easy access to electrical infrastructure.

“We have a lot of historic buildings that might not be appropriate for PV, for many reasons. They may have aging electrical infrastructure, or the tile can be challenging to work with,” Gould said.

Among the buildings selected for PV are Parking Structure 5 (the largest of the 18), Automotive Innovation Facility, Maples Pavilion and Braun Music Center.

The campus’s grid-like layout makes it very suitable for solar energy, since Palm Drive faces magnetic north.

“We’re kind of lucky that we have this grid layout that has the back of the buildings essentially facing south, which is the preferred orientation,” Gould said.

Gould emphasized that although SESI is a step in the right direction, there is more to be done in the future. Reducing energy use, he says, should always come before improving the supply. For example, he mentioned that by installing better fume hoods in the labs, implementing better lighting systems in dorms and updating buildings to today’s standards, Stanford can reduce energy use by one-third.

Even so, making the transition from fossil fuel cogeneration to SESI is “the biggest single thing we could do,” he said.

On behalf of SSS, Jiang agrees. He noted that large projects like SESI, while beneficial, are not the only way to make Stanford more sustainable and encouraged students and administrators to work together toward smaller goals.

“I encourage Stanford administrators, faculty and fellow students to carefully examine how to achieve not just major steps forward such as SESI but also how to achieve a high standard of sustainability in every aspect of campus life,” he said.

Gould is optimistic about future opportunities to reduce overall energy use on campus. As technology continually advances, he and the SESI team would like to see action beyond this project to make Stanford more energy-efficient and to decrease the use of power from non-renewable sources.

“There’s always technology improving,” he said. “And that should be layered into Stanford’s efficiency programs as well.”

Contact Sarah Ortlip-Sommers at sortlip ‘at’ stanford.edu.