Energy from Sewage

| Sewage heat-fed heat pumps provide district heating to Újpest, a northeastern district of Budapest with over 100,000 habitants

Below the principal square of Újpest is a large sewage main collector with an average hourly flow of over 800 cubic meters. Part of this flow is redirected to an engine house built under the square below a parking lot. It is filtered by a specifically designed screening unit and led to purpose-built, self-cleaning heat exchangers to recover its thermal energy. The used sewage is directed back to the main collector while the recovered thermal energy is passed onto two large industrial heat pumps. These heat pumps heat and cool the area’s brand-new market hall, a municipal office building and the over 100-year old city hall of the district.

The combined served floor space is 12500 m2 and the system has been in operations since 2017.

The system supplies 100% of the heating and cooling needs of the buildings. The heat pumps provide a forward temperature of 60°C during the winter season and 7°C during the summer months. COP/EER figures reach up to 3,9/5,8, respectively due to the relatively constant 17°C temperature of the sewage all year round. The currently installed heat pump capacity is 1.7 MW and the system is designed to be able to provide heating and cooling energy simultaneously depending on needs. Operation is remotely controlled by a unique software designed for this purpose. The configuration of the system allows for the capacity scale-up. Additional heat pumps along with a newly designed self-cleaning screening unit and fine-tuned heat exchangers are planned to be installed to serve new buildings now under development in the area. Most pipe works have been already laid for the planned expansion. The 500 cubic meters per hour minimum sewage flow in the main collector allows for the doubling of the current heating and cooling capacity.


EHPA invites everyone to submerge themselves in the possibilities that heat pumps are capable to offer in several industrial sectors. To read more stories the updated booklet is currently available on EHPA’s website.