Stock Photo - 14 July 2022, Saxony-Anhalt, Halle: The secondary clarifiers at the Halle-Nord wastewater treatment plant operated by Hallesche Wasser und Stadtwirtschaft (HWS, photo taken by drone). The sewage treatment plant is to be able to supply itself entirely with self-generated electricity by 2026. To achieve this, firstly the power consumption of the plants is to be reduced, secondly more electricity is to be generated from sewage gas in a combined heat and power plant, and thirdly a folding solar roof is to be erected over the basins. The sewage treatment plant is the largest energy consumer within HWS. In 2021, 10.5 gigawatt hours of electricity were consumed to treat almost 18 million cubic meters of wastewater. Photo: Jan Woitas/dpa. - Halle/Saxony-Anhalt/Germany