ENGIE’s commercial battery project drive $100k annual wedge into California’s water-energy nexus

LinkedIn
Twitter
Reddit
Facebook
Email
Three of SDWA’s facilities are equipped with sizeable rooftop PV generation. Image: San Diego Water Authority.

California’s recent droughts and ongoing need to economise water use have inspired more commercial energy storage at a local water board, with ENGIE Storage delivering a project for the San Diego Water Authority.

The new battery energy storage project is expected to save the Authority (SDWA) US$100,000 per year on its energy costs. The batteries will be used to store low-cost solar energy for use during peak times and times of low solar generation. SDWA and ENGIE Storage, which was formerly known as Green Charge prior to its acquisition by the European utility, struck up a deal for the project in May 2017.

The batteries are being delivered under one of ENGIE Storage’s storage ‘as-a-service’ business models – they are being installed at no front cost to SDWA. Sited at Twin Oaks Valley Water Treatment Plant, they are coupled with 4,800 PV panels, already in place, that generate around 1.75 million kWh of power annually.

Andrea Altmann, senior management analyst at SDWA’s Energy Program, told Energy-Storage.News that the battery energy storage is a 1,000kW system which can store 2,000kWh per day. Altmann confirmed that the Water Authority “will be evaluating opportunities for more battery storage in the future,” in addition to exploring the construction of a possible 500MW pumped hydro facility and a handful of other initiatives.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The system is worth around US$2 million, with ENGIE Storage and SDWA striking up an agreement that the storage provider will own and operate it for 10 years. After this first decade, SDWA can consider purchasing the system, extending the existing agreement, or remove the project altogether from the site if desired. US$1 million in funding was available to the project through California’s SGIP (Self-Generation Incentive Program) which incentivises solar, and energy storage installed with solar.

It’s the latest project in California from the water sector. A project from fellow C&I energy storage market leader Advanced Microgrid Solutions (AMS) for Long Beach Water Department to build a 500kW / 3,000kWh energy storage system was expected to save the Department around US$150,000 a year when it was announced in late December 2017. Meanwhile, Los Angeles Department of Water and Power (LADWP) contracted Doosan GridTech to build a 20MW lithium-ion battery energy storage system (BESS), aimed at reducing LADWP’s reliance on natural gas.

15 September 2026
San Diego, USA
You can expect to meet and network with all the key industry players again in 2025 from major US asset owners, operators, RTOs and ISOs, optimizers, software and analytics providers, technical consultancies, O&M technology providers and more.
3 November 2026
Málaga, Spain
Understanding technology and supplier selection for Europe’s utility-scale PV market in 2027. PV ModuleTech Europe 2026 is a two-day conference that tackles these challenges directly, with an agenda that addresses all aspects of PV module, inverter and battery supplier selection; product availability, technology offerings, supply chain traceability, quality assurance, factory auditing, system reliability, and supplier bankability.

Read Next

Premium
September 8, 2026
PJM has proposed a major overhaul of how it procures power capacity in response to surging data centre demand that has driven auction prices up more than 1,000% in two years and threatens to add US$70 per month to average household electricity bills by 2028.
September 8, 2026
EPC Renewables has signed an MoU with state-linked utility Energy Fiji Limited for the development of the Yaqara Solar & Battery Project.
September 8, 2026
Octopus Australia has referred the Blackstone battery energy storage system (BESS), a 500MW/2,000MWh standalone facility, to Australia’s federal government for assessment under the Environment Protection and Biodiversity Conservation (EPBC) Act.
September 7, 2026
Tech giant Google, Tesla, utility Pacific Gas and Electric (PG&E), and distributed energy resource (DER)-focused company Sunrun are launching a new virtual power plant (VPP) in California, US.
September 7, 2026
Pakistan’s National Electric Power Regulatory Authority (NEPRA) has approved plans to require bidders in a renewable energy auction to include energy storage.