Utrecht Wastewater Heat Pump (Eneco and De Stichtse Rijnlanden)
Goal: Eneco aims to make all the energy it supplies climate-neutral by 2035, and the Netherlands plans to phase out natural gas in buildings by 2050. The project makes the district heating of Utrecht and Nieuwegein more sustainable.
Problem: The network, the oldest in the Netherlands, still relies partly on gas-fired heat. At the same time, the Utrecht sewage plant in Overvecht treats about 65 million litres of wastewater per day. The treated water stays at about 12 °C in winter and 24 °C in summer, and its heat was simply discharged into the river Vecht.
Solution: Eneco built the largest heat pump in the Netherlands on the plant’s grounds, in cooperation with the water authority. A heat exchanger draws heat from the treated water, taking about 2,000 cubic metres per hour. The heat pump then raises the temperature to 75 °C or more and feeds it into the district heating grid. A large buffer vessel helps cover demand peaks. The system was officially opened on 6 September 2024.
Impact: It delivers about 27 MW of heat, supplies roughly 20,000 households and covers about 15% of the network’s heat demand. It saves around 30,000 tonnes of CO₂ per year.
The figures are the operators’ own statements.
