The Hague – Leading solar testing and metrology company Eternal Sun Group today announced the appointment of Fokko van der Zee as Chief Executive Officer. He takes over from long-serving CEO Florian van Rijn van Alkemade, who led the company for ten years through a period of sustained growth and aspires to explore opportunities outside of the Eternal Sun Group.

With an extensive executive background at GE, Rheem, Nedap, and Thales, Van der Zee brings a wealth of leadership expertise to the fast-growing Eternal Sun Group. Having held senior roles in both multinational corporations and rapid-scaling technology companies, his appointment marks a new phase of expansion and evolution for the company. Inspired by the accelerated development of the solar industry, Van der Zee said he is looking forward to making a significant contribution to the energy transition together with the global team.

“Florian hands over a great company. The Eternal Sun Group has a strong market position that we will further expand,” said Van der Zee.

Departing CEO Van Rijn van Alkemade has led Eternal Sun Group since 2016. During his tenure, the company grew from scale-up, with 18 full-time employees (FTE) to an established mid-size company of 145 FTE. It also expanded its international footprint with office locations in six countries across three continents and further developed its technology platforms.

Under Van Rijn van Alkemade’s leadership, Eternal Sun acquired the metrology division of U.S. solar equipment pioneer Spire Solar, China-based SunChine, which offers factory-inspection services, and most recently, German LED cell metrology pioneer WAVELABS. The combined technology portfolio now provides a full range of testing and characterization equipment, from cell to module level.

This latest acquisition was completed with support of Eternal Sun’s new investor shareholder Bolster Investment Partners, which acquired an 80% stake in the company from start-up investor Vermec (2014) and scaling investor the ABN AMRO Sustainable Impact Fund (2019).

Bolster has a sweet spot in enabling the growth of mid-sized companies that have a leadership position in niche markets. One of Bolster’s strengths is to support companies with a buy-and-build investment strategy, which they put in practice immediately after investing in Eternal Sun in May 2025, closing the acquisition of WAVELABS only one month later, in June 2025. This was recognized by the Dutch investment community with the award of the prestigious Sijthoff M&A Community “Best Small-Cap Deal 2025” to Bolster and Eternal Sun.

Erik Bentschap Knook, who serves as Eternal Sun’s Chief Commercial Officer since 2016, said Van Rijn van Alkemade had demonstrated outstanding leadership, and that the incoming CEO appointment represents the next step in the company’s evolution. “We have achieved impressive results over the past decade and have demonstrated our ability to supply our customers with innovative equipment and services in a highly dynamic and competitive market,” said Bentschap Knook.

Chief Technology Officer Stefan Roest, who founded Eternal Sun as a Delft University of Technology spin-off in 2011, continues to lead the company’s technological development. “I am very grateful to Florian for his excellent leadership of the company over the past decade. We are now strongly positioned to meet the needs of manufacturers and researchers globally.”

“Whether it is established crystalline silicon, thin-film, or emerging tandem and perovskite technologies, the integrated Eternal Sun | WAVELABS’ offering is truly unparalleled in the solar market,” said Roest. “The future is tandem, and here we have just the technology to lead. I’m excited to welcome Van der Zee as CEO, helping expand the global impact of our solar simulation, testing, and in-line characterization solutions for cells and modules.”

About Eternal Sun Group
Eternal Sun Group is a global leader in solar module and cell testing technology. With its advanced simulators and inspection services, the company supports manufacturers, laboratories, and developers in over 60 countries. Operating globally, Eternal Sun Group continues to set the standard in the solar metrology through innovation and expertise.