Renewable Energy

Stanford’s 100% renewable electricity aspiration is a reality

Accelerating a transition from fossil fuel-based energy sources to renewables is a key component of the university’s sustainability and climate action goals. Thanks to the efforts of the Stanford Energy Systems Innovation (SESI) program, Stanford achieved 100% renewable electricity in the spring of 2022 after its second solar generating station went online. This transformative energy system led to an 80% reduction in greenhouse gas emissions in 2023 compared to Stanford's 2011 emissions, three years in advance of the target set in the university's long-range planning process.

Living Lab Field Trip with Explore Energy House

On-Site Solar

The 11 sites of rooftop solar panel technology across Stanford generate 4.1 megawatt alternating current (MWac) of solar energy that feed directly into campus operations. These arrays were purposefully selected from over 60 possible campus locations based on factors such as impact on historic buildings, orientation, roof size, and construction impacts. 

Off-Site Solar

Stanford’s commitment to renewable energy is also supporting California’s solar energy market. The university has partnered with photovoltaic (PV) energy companies to create long-term power purchase agreements (*PPAs), which led to the construction of the Stanford Solar Generating Station #1 in 2016 and the Stanford Solar Generating Station #2 in 2022.  

*Under Stanford's solar PPAs, the solar facility owner sells the power generated back to Stanford at a fixed price without needing to actively manage facilities.

Located in Southern California, the 2016 solar generating station is a 54-MWac facility utilizing single-axis tracking technology, a system where panels tilt on one axis to follow the sun’s movement throughout the day for maximum energy production. The 2022 solar generating station, a 63-MWac facility located in Central California, features an innovative 50-MW lithium-ion battery. This battery can store an estimated 200 megawatt hours (MWh) of solar power, ensuring that consumers receive renewable electricity not only when the sun is shining, but 24 hours a day and seven days a week.  

The university's second solar generating station significantly boosted its renewable capacity, bringing it close to, and occasionally exceeding, its annual electricity consumption by generating an average of about 280,000 MWh each year. When the university produces more renewable energy than it needs to meet its goals, it can sell the surplus Renewable Energy Certificates (RECs) to other electricity users in California, helping them achieve their own renewable energy targets.

Renewable Energy Certificates (RECs)

One REC represents 1-MWh of electricity generation connected to the shared electricity grid, and serves as a way to distinguish who can exclusively claim to be using that renewable electricity production. Since physical electricity becomes impossible to trace once it is delivered to the grid, RECs allow individuals and organizations to track their generation and use of renewable electricity.

Trading RECs helps organizations ensure the financial stability of investment in renewable electricity. In Stanford’s case, the contracted solar PPAs exceed the equivalent of the institution’s annual electricity consumption. Stanford may opt to redistribute those RECs in the market so that others can acquire them to meet their own renewable electricity needs. Inversely, the institution could acquire more RECs to help meet its renewable electricity commitment in the future.