The Battery Energy Storage System (BESS) is the largest behind-the-meter (BTM) project in Arizona and ranks as the fourth largest BTM installation in the United States, setting a new benchmark for industrial energy innovation.

Ameresco, Inc., (NYSE: AMRC), a leading energy solutions provider dedicated to helping customers navigate the energy transition, today announced the development and commercial operation of a 50MW/200 MWh battery energy storage system (BESS), the largest behind-the-meter (BTM) project in Arizona. Achieving commercial operation in October 2025, this milestone marks a significant advancement in the state’s energy infrastructure. The BESS was developed in Kingman, Arizona for Nucor, the largest steel producer in North America. Nucor’s bar mill is undergoing a major expansion that includes the installation of a new electric arc furnace. This expansion will help boost the facility’s production capacity to 600,000 tons annually, strengthening Nucor’s operational capabilities at the site.

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Jonathan Mancini, Senior Vice President of Solar & BESS Project Development at Ameresco, delivered remarks at the recent Nucor event.

Construction began in December 2024, featuring 58 Tesla Megapack 2XL units under a 20-year Storage Services Agreement (SSA). The Ameresco-owned battery system was installed at a Nucor substation within Mohave Electric Cooperative’s territory and operated by Arizona Electric Power Cooperative (AEPCO), part of the Arizona G&T Cooperatives. Ameresco will deliver a 25 MW AC solar asset, scheduled to begin operation in 2026, further supporting Nucor’s energy transition and site expansion.

“We are thrilled to have been selected for this groundbreaking BESS project,” said Jonathan Mancini, Senior Vice President - Solar & BESS Project Development at Ameresco. “By placing a battery energy storage system onsite at Nucor’s Kingman plant, we are helping to support their expansion and create a more resilient, reliable and clean energy future.”

Ameresco’s onsite battery Asset will help stabilize the electric load from Nucor’s new arc furnace, reducing strain on the grid. By smoothing energy demand, it makes it easier for the utility to manage power fluctuations and boosts the use of renewable energy.

“The battery energy storage system at our Kingman mill is a site-specific solution developed in response to the unique grid that serves the plant operations and smooths out our energy demand,” said Matt Blitch, Vice President & General Manager at Nucor. “We’re grateful for the collaboration with Ameresco and our utility partners to deliver a system that supports our expansion and maintains operational reliability.”

GreenFront Energy Partners advised Nucor on the contracting and structuring of solar and storage solutions at Kingman.

To learn more about the battery energy storage solutions offered by Ameresco, visit https://www.ameresco.com/batteries-and-energy-storage/.

About Ameresco, Inc.

Founded in 2000, Ameresco, Inc. (NYSE: AMRC) is a leading energy solutions provider dedicated to helping customers reduce costs, enhance resilience, and decarbonize to net zero in the global energy transition. Our comprehensive portfolio includes implementing smart energy efficiency solutions, upgrading aging infrastructure, and developing, constructing, and operating distributed energy resources. As a trusted full-service partner, Ameresco shows the way by reducing energy use and delivering energy infrastructure solutions to Federal, state and local governments, utilities, educational and healthcare institutions, housing authorities, and commercial and industrial customers. Headquartered in Framingham, MA, Ameresco has more than 1,500 employees providing local expertise in North America and Europe. For more information, visit www.ameresco.com.

The announcement of the development of a renewable energy asset by Ameresco is not necessarily indicative of the timing or amount of revenue from such asset, of the company’s overall revenue for any particular period or of trends in the company’s overall total assets in development or operation. This project was included in our previously reported assets in development as of June 30, 2025.

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