Heating and cooling from sewage sludge
28th November 2025
ITALY: The city of Peschiera Borromeo, near Milan, is home to Italy’s first district heating and cooling plant powered by biogas produced from sewage sludge.
The plant, operated by wastewater treatment company CAP Evolution, will reduce approximately 2,800 tons of CO₂ annually and guarantee energy savings of up to 20% for the users served.
The plant uses two cogeneration units that convert biogas into electricity and heat. Electricity is used to power the purifier, while heat stabilises the digesters and feeds the district heating network. During the summer months, when heat demand drops, the system converts thermal energy into chilled water at 7°C through an absorption chiller, also enabling district cooling of the plant’s offices and a nearby commercial space.
The energy produced covers the purifier’s needs and serves various local users, including three company sites, municipal offices, a retail outlet, and an apartment building. Overall, annual production is expected to be approximately 1GWh of thermal energy and 585MWh of cooling energy, reducing air conditioning costs for users by 15% to 20%.
