The CPUC recently approved one of the largest utility-scale battery storage installations in the country, in an effort to improve grid resiliency. The approval came in the wake of rolling blackouts resulting from a historic heatwave, as traditional power plants were unable to keep up with demand. The newly approved battery capacity, totaling 1.2 gigawatts, will be able to charge during the day using excess energy produced by solar farms, and discharge during the evening as demand increases and solar production falls. This additional capacity aims to avoid future rolling blackouts like the ones experienced in early August.
While utility-scale battery installations aim to avoid blackouts due to insufficient energy supply, a building-scale battery-solar installation can help reduce your utility bills even further than either system alone. While the scale is smaller, the principle is similar: rooftop solar panels charge a battery system, which can then discharge to reduce demand spikes from large equipment starting up, or shift consumption from the grid to times when rates are lower. The combination of battery storage and solar allows solar-generated energy to be used even when the sun is not shining. A sufficiently sized battery even keeps your essential systems powered during a grid outage. ERI can provide a solar-battery feasibility assessment, including monthly generation with Time of Use assessment, economics, utility rate analysis, and utility cost savings.
An example of a smaller-scale behind the meter storage solutions is at Pleasanton Unified School District (PUSD). The district recently installed solar carport canopies and battery storage at Amador Valley High School. The system can generate over 1 MW of energy, with a battery energy storage system of 660 kWh. This system offsets 97% of the school’s electricity use and the battery storage system provides protection against future time-of-use rate increases. Overall, the project is projected to save PUSD more than $2.2 million over the 25-year expected useful life of the project.