Solar + storage powers Northern Calif. water treatment plant
A Northern California community has flipped the switch on a 5 MWdc solar + battery energy storage system that is powering a water treatment facility. The city of Vacaville held a “flip the switch” ceremony this week to celebrate the energization of the new facility at the Easterly Wastewater Treatment Plant (EWWTP).
Designed to offset the annual electricity demand at the EWWTP facility, the solar + storage system will generate nearly 8.1 million kWh of renewable electricity annually. The system increases overall energy efficiency while lowering utility bills, providing a projected savings to the city of more than $25 million in electricity costs over its 20-year lifespan.
“Vacaville’s sustainability goals are about better outcomes for people, healthier air, smarter use of resources, and reliable public services,” said Vacaville Mayor John Carli. “By pairing solar with smart battery storage at an industrial facility that treats an average of 7.5 million gallons of wastewater daily, this project will help power operations essential to minimizing public health risks and our environmental impact.”
Surging sustainability
Developed in partnership with ForeFront Power, the project advances Vacaville’s sustainability strategy to reduce greenhouse gas emissions, stabilize energy costs, and strengthen reliability at a critical 24/7/365 public facility. Powering essential wastewater treatment operations with solar further reduces carbon emissions and supports better air quality across Solano County.
During the day, the solar energy array will provide power to electrical loads — including large motors, equipment, HVAC, security systems, and IT — while the battery storage banks excess energy produced during extended sunshine. Stored energy can be dispatched at night, on cloudy days, or whenever facility demand exceeds solar production, ensuring consistent, cost-effective power for essential services. The EWWTP’s energy‑intensive operations can now draw on smart battery reserves to avoid paying utility peak rates, cutting local energy costs while easing strain on California’s grid.
“We applaud the city of Vacaville for its leadership in deploying clean, renewable energy at a mission-critical facility,” said Ruben R. Fontes, CEO of ForeFront Power. “The Easterly WWTP now benefits from solar energy generation paired with intelligent storage, producing power when it’s abundant and dispatching it when it matters most, supporting local public health and community resilience for decades to come.”
PPA aids cost savings
The EWWTP solar and storage system was developed through a 20-year Power Purchase Agreement (PPA) between the Vacaville and ForeFront Power. Under the terms of the PPA, ForeFront Power owns and maintains the system, while the city purchases the electricity at a fixed, lower rate than the utility, ensuring long-term budget predictability and protection from rate increases. ForeFront Power will continue to operate and maintain the system for the duration of the PPA at no cost to the city.
This project supports the city’s broader sustainability initiatives, including the Energy and Conservation Action Strategy (ECAS), a long‑range plan to reduce carbon emissions and conserve resources. ECAS calls for community‑wide measures that boost energy independence, curtail utility spending, and improve air quality through reduced emissions from municipal facilities. The EWWTP solar and storage system advances these goals and complements the city’s ongoing Sustainable Energy Project, which focuses on deploying solar across multiple facilities, enhancing backup power at critical sites, and delivering long‑term taxpayer savings.
