WesTech partnered with Cleanergy to bring the Cleanergy GasBox biogas generator to the United States. The GasBox generates electricity and heat from biogas using a Stirling engine. The GasBox requires minimal to no gas cleaning, which allows for small and midsize wastewater treatment plants to achieve the power-generating benefits of biogas utilization. The GasBox can also run on biogas with a methane concentration as low as 18 percent, which eliminates the need at larger plants to burn off this biogas with a natural gas supplement.