The Willey Battery Energy Storage System is a 6,000kW energy storage project located in Hamilton, Ohio, US.

The electro-chemical battery energy storage project uses lithium-ion as its storage technology. The project was announced in 2015 and was commissioned in 2016.


The Willey Battery Energy Storage System was developed by Renewable Energy Systems . The project is owned by Sumitomo (100%).

The key application of the project is frequency regulation.

Contractors involved

Renewable Energy Systems, Sumitomo and Toshiba have delivered the battery energy storage project.

Additional information

The Energy Storage System is funded by Sumitomo Corporation Group. The monitoring, dispatch and control of the system will be handled by the Resolve Energy LLC storage platform, a proprietary technology developed by RES Americas. Resolve Energy LLC will manage the system for maximizing revenue while minimizing battery degradation.

About Renewable Energy Systems

Renewable Energy Systems Ltd (RES), a subsidiary of Renewable Energy Systems Holdings Ltd, is a renewable energy company that designs, develops, constructs, finances and operates energy development projects. The company offers project development, design and engineering, construction, commissioning, operation and maintenance, procurement, resource assessment, project engineering, asset management, project management, technical support and advisory services. It undertakes offshore wind projects, solar projects, transmission projects and energy storage projects. The company has operations in the UK and Ireland, the US, Australia, Canada, France, Germany, Turkey and Scandinavia. RES is headquartered in Kings Langley, the UK.


All publicly-announced energy storage projects included in this analysis are drawn from GlobalData’s Power IC. The information regarding the projects are sourced through secondary information sources such as country specific power players, company news and reports, statistical organisations, regulatory body, government planning reports and their publications and is further validated through primary from various stakeholders such as power utility companies, consultants, energy associations of respective countries, government bodies and professionals from leading players in the power sector.