UC San Diego Expanding Energy Storage with 2.5 MW of Batteries


One of the largest battery-based energy storage systems (ESS) in the United States will be installed at the University of California, San Diego. The 2.5 MW, 5 MWh system — enough to power 2500 homes — will be integrated into the university’s microgrid, which generates 92% of the electricity used on campus annually. UC San Diego’s microgrid is considered one of the most advanced in the world, with the university planning additional energy storage systems in the future.

“UC San Diego is committed to practices that promote sustainability and innovation, not just on our campus, but in our community and our world,” said Gary C. Matthews, Vice Chancellor for Resource Management and Planning. “Energy storage has the potential to transform the global energy landscape. It can help make renewable energy sources more reliable and is critical to a resilient, efficient, clean, and cost-effective grid. We are proud to help advance this technology.”

Energy storage is seen as key to enhancing grid reliability as solar and other intermittent renewable resources become more widely adopted. It has become a much talked about industry as new advances in battery technology come to light.

Energy storage is considered so important that the California Public Utilities Commission (CPUC) decided last year to establish an unprecedented energy storage target for the state: 1.3 GW. This is to be procured and installed by three of the state’s investor-owned utilities by 2024. The CPUC’s mandate broke new ground by trying to establish a regulatory system in which utilities, third-party storage providers, and potentially customer-owned storage assets can play an integrated role.

The 2.5 MW, 5 MWh ESS at UC San Diego was purchased from BYD. The ESS uses high-performance lithium-ion iron-phosphate batteries that are known for being highly reliable and environmentally friendly. The company’s rechargeable batteries contain no heavy metals or toxic electrolytes, and during the manufacturing process, all caustic or harmful materials are avoided. The batteries are also considered non-explosive and fire-safe, even in direct flames. The company has supplied more than 100 MWh of fixed energy storage stations around the world.

“UC San Diego is renowned for their efforts in green energy production technologies and we are thrilled to partner with them,” said Stella Li, BYD Corporate Senior Vice President. “Together, we seek to ensure that renewable power can be utilized as a reliable generation source enabled by environmentally-friendly battery storage.”

This system is the latest addition to UC San Diego’s portfolio of energy storage devices. Other devices currently in place include the following:

  • 30 kW ultra-capacitor-based energy storage system from Maxwell Technologies, Inc. The system will be combined with Soitec’s Concentrated Photovoltaic Technology, which is already installed on campus.
  • Second-life battery demonstration site. Although electric vehicle batteries usually only have a vehicle lifetime of 8-10 years, they still have significant capacity left for alternative uses, such as stationary energy storage.
  • 3.8 million gallon thermal energy storage. Waste heat from the plant is also used as a power source for a water chiller that fills a 4 million gallon storage tank at night with cold water. The water is used during the warmest time of day to cool campus buildings.

Once the new ESS is installed in spring 2015, UC San Diego will be eligible for up to $3.25 million in financial incentives through the Self-Generation Incentive Program (SGIP). SGIP is a California ratepayer-funded rebate program, overseen by the CPUC, that provides incentives for the installation of clean and efficient distributed generation technologies. It is available to retail electric and gas customers of the four California investor-owned utilities: Pacific Gas & Electric, Southern California Edison, South California Gas, and San Diego Gas & Electric.