ESS Energy Warehouse™ will deliver resilient energy infrastructure

ESS Inc. (NYSE: GWH), a leading manufacturer of long-duration iron flow batteries for commercial and utility-scale energy storage applications, has been selected by Consumers Energy, Michigan’s largest energy provider, to provide a battery system for a solar and storage microgrid. Consumers Energy will deploy ESS’s Energy Warehouse platform as part of a microgrid powering a gas compression facility in Michigan.

The project, which includes the first iron flow battery to be used for a gas compression plant, underscores the capabilities of ESS’s Energy Warehouse to deliver low-cost, long-duration energy storage over a 20+ year operational lifespan. When paired with solar photovoltaics, the Energy Warehouse provides a sustainable, resilient energy storage solution for critical infrastructure.

Consumers Energy provides natural gas and/or electricity to two thirds of Michigan's 10 million residents and is the principal subsidiary of CMS Energy. This project will help to achieve the goals laid out in the Energy Storage Roadmap for Michigan, released in April by the Michigan Department of Environment, Great Lakes and Energy, which calls for 1,000 megawatts (MW) of storage by 2025 and 4,000 MW by 2040.

“ESS is proud to provide our safe and non-toxic battery storage system to a leading utility provider in the Midwest serving millions of customers,” said Hugh McDermott, SVP of business development and sales at ESS Inc. “We are especially pleased to have our first project for Consumers Energy be a solar-plus-storage microgrid – a hugely beneficial solution for utilities and commercial/industrial customers who need sustainable and cost-effective energy resilience solutions.”

“Consumers Energy’s partnership with ESS on this first-of-its-kind project is another positive step toward a cleaner energy future for Michigan,” said Dennis Dobbs, VP of gas engineering and supply at Consumers Energy. “This project delivers on our goal of producing and storing clean, renewable electricity to help the environment, reduce electric bills and increase operational efficiency at the compressor station. And by integrating ESS’s Energy Warehouse we are able to ensure the safe, dependable operation of our critical infrastructure.”

Utilizing earth-abundant iron, salt and water for its electrolyte, and simple materials for battery components, the ESS Energy Warehouse is a durable, environmentally safe, long-duration storage solution that is ideally suited for time-shifting renewable energy, managing a facility’s demand charges, and smoothing the intermittency of renewables on a constrained grid. It aligns well with the life span of solar and wind projects, supporting those applications’ low levelized cost of energy requirements.

About ESS Inc.

At ESS (NYSE: GWH), our mission is to accelerate global decarbonization by providing safe, sustainable, long-duration energy storage that powers people, communities and businesses with clean, renewable energy anytime and anywhere it’s needed. As more renewable energy is added to the grid, long-duration energy storage is essential to providing the reliability and resiliency we need when the sun is not shining and the wind is not blowing.

Our technology uses earth-abundant iron, salt and water to deliver environmentally safe solutions capable of providing up to 12 hours of flexible energy capacity for commercial and utility-scale energy storage applications. Established in 2011, ESS Inc. enables project developers, independent power producers, utilities and other large energy users to deploy reliable, sustainable long-duration energy storage solutions. For more information visit www.essinc.com.

About Consumers Energy

Consumers Energy, Michigan’s largest energy provider, is the principal subsidiary of CMS Energy (NYSE: CMS), providing natural gas and/or electricity to 6.8 million of the state’s 10 million residents in all 68 Lower Peninsula counties.

Forward-Looking Statements

This communication contains certain forward-looking statements, including statements regarding ESS’s and its management team’s expectations, hopes, beliefs, intentions or strategies regarding the future. The words “anticipate”, “believe”, “continue”, “could”, “estimate”, “expect”, “intends”, “may”, “might”, “plan”, “possible”, “potential”, “predict”, “project”, “should”, “would,” “will” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements are based on ESS’s current expectations and beliefs concerning future developments and their potential effects on ESS. Many factors could cause actual future events to differ materially from the forward-looking statements in this announcement. There can be no assurance that the future developments affecting ESS will be those that we have anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond ESS’s control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. Except as required by law, ESS is not undertaking any obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise.