Spire Solar is a leading global solar company providing turnkey solar simulation solutions for module factories as well as calibration and certification laboratories. Spire Solar is part of the Dutch Eternal Sun Group, a solar testing company which also owns Eternal Sun BV, a Dutch steady state solar simulation equipment provider.

Since 2002 the Spi-Sun Simulator has become the industry standard in module performance testing. It is now used by more than 30 standards testing laboratories worldwide and is a staple in mass production lines around the globe and allowed new and experienced customers to rapidly enter and ramp to full production without concern for start up difficulties.