Eternal Sun Group

Eternal Sun makes solar simulators for IV testing of photovoltaic modules and cells. The range includes XENON-based flash simulators, LED-based steady-state simulators and light soakers, and temperature-controlled lab flashers. The company also offers PV import testing and factory inspection services, including in the port of Rotterdam and in China.

The website names research labs, solar module producers and solar power producers as customers. It also describes support for customers who set up IEC 61215, IEC 61730 and IEC 61853 certification labs. Revenue comes from equipment sales and from testing and inspection services.

Eternal Sun was founded in 2011 as a spin-off from Delft University of Technology and acquired the solar simulator division of Spire Solar in 2016. Its OdinSpire joint venture started PV testing services in Rotterdam Harbor in 2018, and a sales and service office was set up in Shanghai the same year. In 2025 Bolster Investment Partners became majority shareholder, and the company acquired WAVELABS, now WAVELABS Eternal Sun GmbH in Leipzig. Open positions listed include technical specialists, a PLC engineer, an electrical support engineer, a financial controller and an HR officer, all based in 's-Gravenhage.

Product: Flash (XENON) and LED steady-state solar simulators, light soakers and temperature-controlled lab flashers for PV module IV testing, plus PV import testing and factory inspection services.