Pacific Gas & Electric Company (PG&E) has launched Seasonal Aggregation of Versatile Energy (SAVE), an Electric Program Investment Charge (EPIC) demonstration and virtual power plant (VPP), harnessing residential distributed energy resources to reduce local grid constraints.
The demonstration program, looked upon by multiple aggregators and the Demand Side Analytics research team, will include up to 1,500 electric residential customers with battery energy storage systems and up to 400 customers with smart electric panels. From June through October 2025, the VPP will be dispatched for up to 100 hours to provide localized support by supplying battery power and load flexibility to selected neighborhoods during local peak demand periods when electric substations and feeder lines approach capacity limits.
SAVE is a demonstration VPP in which PG&E provides participating aggregators, including Sunrun and SPAN, with week-ahead hourly signals informed by grid needs. The hourly signals indicate PG&E's energy capacity needs at a specific day, time, and duration, to allow aggregators to shift participating customers' usage to meet those needs. The VPP will employ newly developed software from Tesla and SPAN to meet the requirements.
SAVE will be activated across PG&E's service area, with a concentration of assets in the South Bay Area and the Central Valley. Factors influencing the deployment of SAVE include areas where there is potential for overloading during peak summer hours, where the participating aggregators have a concentration of customers, and where PG&E will test capabilities across diversified grid needs (varying load shapes). Additionally, more than half (60%) of SAVE customers are in disadvantaged or low-income communities.
SAVE is conducted through PG&E's EPIC program, which helps California investor-owned utilities to demonstrate new technologies and evaluate their support to safety, reliability, and affordability objectives for the benefit of all California electric customers. Funding for the SAVE program is provided through EPIC 4.09B Aggregated Customers on Distribution Circuits (ACDC).
Sunrun solar-plus-storage systems at customers' homes in Northern and Central California will deliver targeted load relief to neighborhoods identified with highly constrained electric grids. Sunrun will be responsible for managing battery dispatches, and all enrolled batteries will retain at least 20% backup reserve to ensure power availability at customers' homes in the event of a power outage.
Sunrun will use an advanced application of Tesla's grid services platform to optimize Powerwall batteries to provide an exact amount of power at specific times to different locations. It will also leverage Lunar Energy's artificial intelligence-enabled forecasting through its Gridshare software platform to dispatch various non-Tesla battery types to meet local grid needs.
SPAN will enroll customers with smart electric panels at homes in Northern and Central California to receive dispatch signals and deliver targeted load relief. SPAN will use its Dynamic Service Rating (DSR) capability to shape home energy demand during peak events to aggregate energy usage remains within operational limits of PG&E's distribution infrastructure.
SPAN customers will be allowed to use their SPAN Home App to adjust their preferences to reflect how the SPAN Panel will manage appliances. SPAN customers will have maximum flexibility to continue using the appliances they require during peak hours, while helping reduce grid congestion.
