(Lugano, Switzerland / Westlake Village, USA) – The Swiss provider of sustainable energy storage solutions Energy Vault Holdings, Inc. and the Californian energy supplier Pacific Gas and Electric Company (PG&E) are working together on a battery plus green hydrogen energy storage system (BH-ESS). A fuel cell using hydrogen from renewable sources will generate electricity for the storage system. The minimum capacity of the hybrid generation/storage system is 293 megawatt hours (MWh) and can be expanded to 700 MWh.
Safety reserve in the event of a power shutdown
The BH-ESS is designed to provide power to the downtown and surrounding areas of the Northern California community of Calistoga, home to more than 2.000 electric customers, for at least 48 hours during grid outages. The storage also serves as a reserve if, for safety reasons, power lines have to be switched off due to a high risk of forest fires or after storm damage (“Public Safety Power Shutoffs”).
The system replaces the commonly used mobile diesel generators, which are used to supply Calistoga with energy in the event of major grid failures. The entire system will be developed on less than one hectare of land and will serve as a model for Energy Vault's future utility-scale hybrid storage systems. The city will lease the necessary land to the company.
The storage remains the property of Energy Vault and is operated and maintained by the company. PG&E enters into a long-term purchase agreement for the purchase of electricity.
Blueprint for further microgrids
The system is capable of black start, meaning it can be started up independently of the power grid when it is switched off. The design makes it possible to create “a cost-effective and completely carbon-free microgrid that can store and distribute renewable energy on demand,” said Ron Richardson, regional vice president, North Bay and North Coast at PG&E.
Under the 10,5-year agreement, Energy Vault will also offer "Distributed Generation-Enabled Microgrid Services" - a type of energy service that uses grid-forming generation and storage resources in combination with demand-side resources to maintain voltage and frequency within the specified to regulate parameters of the utility company.
The collaboration with Energy Vault provides “a template for future community-scale microgrids that successfully integrate distributed third-party energy resources,” PG&E said. Costs to customers are expected to be below the benchmark set by state regulators, which is based on the use of mobile diesel generators.
Commissioning is scheduled for mid-2024
PG&E submitted the project contract to the responsible authority, the California Public Utilities Commission, for review on December 30, 2022. Approval is expected by May 15, 2023.
Construction is scheduled to begin in the fourth quarter of 2023, with commercial operations scheduled to begin at the end of the second quarter of 2024. Once completed, this project is expected to be the first of its kind and the largest green hydrogen energy storage facility in the United States.
Photos
Whether it's a forest fire or a hurricane: PG&E - like many US utilities - often switches off power grids or parts of them for safety reasons. To bridge the grid failures, the company is now installing battery storage units for a microgrid that are filled with electricity from green hydrogen. The photo shows the Walnut Grove region of Sacramento County, California, where severe storms this winter have dismantled numerous power poles. © PG&E
