# Joe Kastner

> Joe Kastner is the co-founder and CEO of Radian Generation, a renewable energy services and software company founded in 2013. His career spans solar project implementation, construction and operations at businesses including NUON Renewable Ventures, MMA Renewable Ventures and Fotowatio Renewable Ventures. In 2008, he testified before a U.S. House subcommittee about utility-scale solar and the Nellis Air Force Base project. He subsequently helped grow Radian’s combination of asset management, software, compliance and cybersecurity services.

- **Role:** Co-founder and CEO at Radian Generation
- **Organizations:** Radian Generation, Renewable Ventures, MMA Renewable Ventures, Fotowatio Renewable Ventures, NUON Renewable Ventures USA
- **Education:** B.S. in Mechanical Engineering, University of Minnesota, M.S. in Energy Engineering, Stanford University, M.S. in Environmental Science and Management, University of California, Santa Barbara
- **Known for:** Co-founded Radian Generation in 2013 and became CEO in 2018., Testified before a U.S. House subcommittee on utility-scale solar on March 17, 2008., Led Radian during its acquisition of Green IT Energy Applications in 2022.

## Career timeline

- **Before 2008** — Consulted on energy efficiency and solar systems; subsequently managed the renewable energy division at NUON Renewable Ventures USA.
- **2008** — Testified at the March 17 U.S. House field hearing in Tucson as MMA Renewable Ventures vice president of implementation and operations.
- **Before 2013** — Held senior management roles at Renewable Ventures, which he co-founded, MMA Renewable Ventures and Fotowatio Renewable Ventures.
- **2013** — Co-founded Radian Generation.
- **2014** — Discussed solar operations as Radian Generation vice president of operations.
- **2015** — Spoke at Solar Power International as Radian Generation chief operating officer.
- **2018** — Became CEO in July, according to Crunchbase.
- **2021** — Joined Richard Matsui on the Currents podcast to discuss solar risk.
- **2022** — Radian acquired Green IT Energy Applications, adding software, operational technology and cybersecurity capabilities.
- **2025** — Discussed operational readiness and portfolio growth in a June interview.
- **2026** — Continues as CEO and co-founder; Radian reported 95 completed client Category 2 registrations in July.

## Achievements

- Co-founded Radian Generation in 2013 and became CEO in 2018.
- Testified before a U.S. House subcommittee on utility-scale solar on March 17, 2008.
- Led Radian during its acquisition of Green IT Energy Applications in 2022.

## Latest updates

- **2026-10** — Radian’s RE+ 2026 event page lists Kastner as CEO and co-founder among the team available for meetings in Las Vegas.
- **2026-07** — Radian announced 95 completed client NERC Category 2 registrations, with 18 additional projects in pre-registration; these are company milestones.
- **2026-03** — Radian shared a video of Kastner and Kellie Macpherson at Infocast 2026, with Kastner expressing confidence in the fundamentals of solar, wind and storage.

## Links

- LinkedIn: https://www.linkedin.com/in/joe-kastner-sfbay/

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Profile page: https://yespress.io/joe-kastner
Published by YesPress — https://yespress.io
Last updated: 2026-10-27