Eos Energy Enterprises Transitions Leadership: Honoring Russ Stidolph and Welcoming Joseph Nigro

Russ Stidolph, who has been a non-executive Chair since April 2018, is stepping down from the Board to concentrate on his full-time role at AltEnergy Acquisition Corp. Stidolph's tenure has been marked by pivotal contributions, particularly in guiding Eos from its early research and development stages to a prominent manufacturer in the energy storage industry. Under his leadership, the company has successfully deployed over 5 GWh of operations and established a robust manufacturing strategy within the United States.

Reflecting on his journey with Eos, Stidolph remarked, “I am proud to have played an integral role in guiding Eos from an early-stage research and development company into a scaled leader of stationary energy storage.” His legacy includes not only securing essential funding but also recognizing the long-term potential of the company, which has been a cornerstone of its success.

Joseph Nigro joins Eos as the new non-executive Chair, bringing with him over three decades of experience in the energy, utility, and infrastructure sectors. His previous roles include Chief Financial Officer of Exelon Corporation and CEO of Constellation. Since joining the Eos Board earlier in 2025, Nigro has been instrumental in shaping the company's strategic direction during a time of rapid growth and expansion in U.S. manufacturing.

Eos CEO Joe Mastrangelo expressed deep appreciation for Stidolph's leadership while highlighting Nigro's capabilities. “Joe’s deep expertise across energy markets, finance, and large-scale operational execution makes him the right leader to guide our Board at this pivotal stage,” Mastrangelo stated. This leadership transition is expected to bolster Eos' efforts to scale production and meet the increasing demand for American-made energy storage solutions.

As Eos Energy gears up for its next chapter, Nigro emphasized the critical role of long-duration storage in the evolving energy landscape. “Eos is building one of the most important energy-infrastructure platforms and is positioned to play a critical role in the future energy mix,” he stated. With the rising demand for energy driven by advancements like AI and electrification, the need for reliable and flexible energy storage solutions is paramount.

Under Nigro's guidance, the Board aims to enhance Eos' operational execution and market expansion, ensuring the company remains at the forefront of innovation in energy storage technology.

The leadership change at Eos Energy Enterprises marks both an end and a beginning. Stidolph's departure is bittersweet, as he leaves behind a strong foundation built on innovation and growth. Meanwhile, Nigro's appointment signals a commitment to continued progress and adaptation in a rapidly changing energy sector. As Eos looks toward the future, its focus on American energy independence and cutting-edge storage technology positions it well to navigate the challenges and opportunities ahead.