FlexGen
FlexGen is a US-based company that specializes in designing, integrating, and operating battery energy storage systems (BESS) and advanced energy management software. Founded in 2009, FlexGen has transitioned from a global microgrid specialist to a leading system integrator focused on grid-connected energy storage solutions in the US market. The company offers hardware-agnostic, turnkey energy storage solutions that combine innovative software with flexible hardware integration. Their proprietary HybridOS™ energy management system enhances operational excellence and reliability, achieving high availability rates. FlexGen has completed over 100 projects across 10 US markets, with a total installed and contracted capacity of 11 GWh, sufficient to power over 225,000 average US homes. Their services include specialized solutions for data centers, analytical site assessments, EMS retrofits, and comprehensive lifecycle support, catering to independent power producers, data centers, and grid operators.
Work at FlexGen in HR or recruiting? Claim this page
Headcount trend
FlexGen went from 197 employees in Jul 2023 to 238 in Jun 2025. Jan to Jun 2025: 39 people joined, 8 left.
Headcount data through Jun 2025
Org structure
Headcount by department
Hiring now
See all jobsSalaries at FlexGen
All salaries2 salary profiles in the US
H-1B sponsorship
The department split adds up all the years listed above. FY2025 alone: 7 filings.
Funding
- Jan 2025 · Debt Financing · $75M · JPMorgan
- Jul 2022 · Series C · $100M · Altira Group LLC
- Aug 2021 · $150M · Apollo Global Management, Inc, Altira Group
- Sep 2018 · Debt Financing · $7M · Altira Group, LLC
- May 2018 · $993K · Altira Group, LLC
- Aug 2015 · Series A · $25.5M · Altira Group, LLC, GE Ventures
Peer reviews
Worked with someone at FlexGen?
Anonymous peer reviews on OffTheRecord
Similar companies
FlexGen FAQ
How many employees does FlexGen have?
FlexGen has about 238 employees, up 9.7% over the 3 months to Jun 2025.
Does FlexGen sponsor H1B visas?
Yes. FlexGen filed 7 H1B (LCA) applications in FY2025, according to the latest U.S. Department of Labor disclosures. Most of them were for Engineering roles.
What is FlexGen's revenue per employee?
FlexGen makes about $351K in revenue per employee, based on $83.5M annual revenue and 238 employees.
How much does FlexGen pay?
6figr has 2 salary profiles for FlexGen in the US, with pay broken down by role, level, gender and ethnicity on the FlexGen salaries page. See FlexGen salaries
How much funding has FlexGen raised?
FlexGen has raised $358.49M in total funding; its latest round was Debt Financing in Jan 2025.
Data from Company Prospectus, DOL LCA disclosures, WARN notices and 6figr salary profiles.
