SCH Number 2024090567

Project Info

Title

Securing Bulk Grid Reliability with a Zero-Emission High-Density Distributed Asset

Description

The Regents of the University of California, University of California San Diego (UCSD) owns and operates an existing microgrid electrical distribution system with onsite generation and storage. The microgrid is powered by the UCSD’s existing energy infrastructure and consists of a 30-megawatt (MW) cogeneration plant, 3 MW of existing solar photovoltaic (PV), a 2.5 MW/5.0 megawatt hour (MWh) battery energy storage system (BESS) and all electrical assets including 12 kV distribution lines, high voltage switchgear, transformers, and associated metering equipment downstream of a 69 kilovolt (kV) substation which is owned and operated by San Diego Gas and Electric (SDG&E). SDG&E provides transmission and distribution services only. The project will upgrade the microgrid’s existing 2.5 MW/5.0 MWh lithium-ion BESS component with a more efficient BESS with a nameplate capacity of 9.8 MW/ 39.2 MWh. The nameplate capacity of the existing BESS, installed in 2015 and operational since 2016, is a 2.5 MW/ 5.0 MWh system. Due to cycle aging degradation of the lithium iron phosphate battery chemistry, string imbalances and software maintenance issues, the existing system’s output can no longer maintain the 2.5 MW/5.0 MWh output. The more efficient BESS would not result in higher energy consumption or expansion of the utilities plant. The minor alteration of the microgrid’s BESS component will secure the UCSD’s microgrid’s reliability and will connect to the existing 12 kV system, mitigate peak load at the SDG&E substation. The upgraded BESS will occupy the same physical footprint as the existing BESS, utilize existing electrical infrastructure, and connect to the bulk electricity system at the same interconnection point. The proposed project meets and exceeds the solicitation goals of prioritizing and accelerating the implementation of feasible and cost-effective zero-emission resources to achieve bulk grid reliability. The project is consistent with the California Energy Commission’s mission of leading the state to a 100 percent clean energy future and will contribute to meeting California’s clean energy goals and support grid reliability.

2 documents in project