Largest wastewater pump in Netherlands to supply heat, save 30,000 tonnes of CO2

Energy supplier Eneco and water authority HDSR in the Netherlands have opened the country’s largest heat pump.

Eneco will use the pump to take heat from HDSR’s treated waste-water and turn it into a new source of energy for the heating grid.

Approximately 20,000 households in the municipalities of Utrecht and Nieuwegein will now have sustainable heating, according to Eneco.

The heat pump has been installed on the site of the Utrecht waste water treatment plant, and was opened a week back by Nanda van Zoelen of HDSR and Eneco’s Chief Operating Officer Assets Karen de Lathouder.

Heat in that treated waste water will now be given a useful purpose

“Our waste water treatment installations treat the wastewater produced by our residents and businesses, which is a process that continues day and night,” said Nanda van Zoelen of HDSR.

“We’re excited that the heat in that treated waste water will now be given a useful purpose and heat around 20,000 households. This new application means a significant drop in the volume of fossil fuels that are needed. We are very proud of this and our efforts to help create a sustainable and circular society.”

Aquathermal energy is a viable way of making the sources for supplying heat more sustainable, in particular using hot water from a waste water treatment plant situated right in the middle of an urbanised area. That is the reason for this partnership between Eneco and HDSR.

Heat pump will draw residual heat from around 65 million litres of treated waste water

Every day, the heat pump will draw residual heat from around 65 million litres of treated waste water. That water, from showers, kitchen taps, dishwashers and washing machines, has temperatures ranging from 12 degrees in winter to more than 22 degrees in summer, according to Eneco.

Thanks to the new heat pump, that heat will no longer simply dissipate, but instead the temperature of the treated water will be reused for the heating grid. A heat exchanger draws the heat from the waste water, after which the large heat pump increases the temperature to 75 degrees and the water is fed into the heating grid, according to the company .

The overall installation includes a heat buffer of around 18 metres high and 18 metres across to make sure that enough heat is available at all times. Every year, it will supply up to 20,000 homes with sustainable heating.

Eneco and HDSR both have ambitions to become climate-neutral. Their combined exploration of possibilities to improve their sustainability has led to this major improvement for the heating grid in the municipalities of Utrecht and Nieuwegein, which share the ambition to become climate-neutral. The new heat pump will save 30,000 tonnes of CO2 per year.

“Thanks to our partnership with HDSR, we can use heat in a circular process,” said Karen de Lathouder, Eneco’s Chief Operating Officer Assets.

“People use heat in their homes, and we then reuse it to supply households with new heat and hot water. This is an excellent way of making our heat more sustainable and accelerating the pace of the energy transition.”