Renewable gas strengthens local supply

Green Power Aarau AG is now processing part of the sewage gas from the AWAU wastewater treatment plant in Telli Aarau. The gas will be fed into Eniwa's natural gas network. Its volume is to be significantly increased with the planned construction of the new wastewater treatment plant.

Aarau, November 2025

Since October, some of the sewage gas from the wastewater treatment plant (WWTP) of the Aargau and Surroundings Wastewater Association(AVAU) in Telli in Aarau has also been used to supply heat locally. According to a press release, Green Power Aarau AG processes the gas, which is then fed into the natural gas network of Eniwa AG.

This replaces fossil natural gas with renewable gas. According to the press release, the quantities are currently still manageable. However, they should be significantly increased with the ARA expansion.

“With this project, we are demonstrating how the by-product sewage gas can be turned into a valuable energy source,” said Hans-Kaspar Scherrer, CEO of Eniwa and Chairman of the Board of Directors of Green Power Aarau AG, in the press release. “The collaboration between AVAU, Green Power Aarau and Eniwa is a strong example of how the circular economy works in practice in the region.” According to Scherrer, the three companies are jointly contributing to a sustainable energy supply and the reduction of CO2 emissions, as well as strengthening local value creation.

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