FlexGen

FlexGen is a leading provider of battery energy storage solutions and the advanced software platform, HybridOS, that is instrumental in enabling today's energy transition. The firm specializes in designing, integrating, and optimizing utility-scale battery storage projects, offering comprehensive services from initial engineering and design to ongoing operations and lifecycle management. Their solutions are critical for meeting the evolving power demands of various sectors, including data centers, and for enhancing grid stability and reliability globally.

Founded in 2009, FlexGen initially developed energy storage products for the United States Military, providing hybrid power systems that significantly reduced fuel consumption and generator runtime for branches like the US Marine Corps and US Army. This foundational experience in demanding environments has shaped their robust and reliable approach to energy storage. The company has since expanded its focus to the commercial sector, leveraging its expertise to address the growing need for efficient and sustainable energy solutions.

While FlexGen is not a traditional investment firm, it has successfully attracted significant capital from notable investors such as Apollo Global Management, Altira Group, General Electric Ventures, and Caterpillar Ventures, underscoring confidence in its technology and market position. The company has also strategically expanded its capabilities through acquisitions, including Powin in 2025 and Clean Energy Services (CES) in 2026, to strengthen its battery leadership and broaden its service offerings. FlexGen's HybridOS software manages over 25 GWh of energy storage systems across more than 200 projects globally, demonstrating its substantial impact on the energy landscape.

The FlexGen team is led by CEO Kelcy Pegler and comprises experienced professionals in software engineering, application engineering, and supply chain management. Their collective expertise is focused on delivering high-performing, reliable, and future-ready storage systems. The firm's proprietary AI-powered platform and US-based Battery Management System (BMS) highlight their commitment to innovation, enhanced cybersecurity, supply chain resilience, and superior performance in large-scale energy storage systems.