With the decision to invest DKK 673 million in green forms of energy, Aalborg Forsyning is one step closer to sustainable and safe heat production - also for future generations. A heat pump, electric boilers and a heat storage facility will contribute to the green conversion of district heating in Aalborg Municipality.
Today, Wastewater Treatment Plant East discharges treated wastewater into the Limfjord. The temperature of the water varies between 8 degrees in winter and 25 degrees in summer. Aalborg Forsyning is now investing in a 6 MW heat pump at the wastewater treatment plant. The pump must harness the energy in the wastewater and convert it into district heating.
Heat pump at Wastewater Treatment Plant East
"Heat pumps are a key element in transforming fossil heat production into the future mix of green technologies," says Per Clausen, Chairman of the Board of Aalborg Supply's Energy Division. He elaborates: "In practice, this means that citizens' wastewater comes back as green district heating in the radiators. In other words, the project is a good example of cross-cutting cooperation across the types of water and energy supply. The so-called "sector link" in Aalborg Forsyning means that we can do even more for the climate."
For Lasse Frimand Jensen, Chairman of the Board of Directors of Aalborg Supply's water division, the project also makes perfect sense. He says: "Normally, a wastewater treatment plant handles the waste water environmentally properly. We still do, but by thinking circularly, we can at the same time use it for energy when what the citizens flush down the toilet is turned into heat. In short, waste water is a valuable resource and a good example of how something that used to be perceived as waste is now part of the circular economy with a significant social value."
Specifically, a new pumping station will be established, which pumps the treated wastewater to the Limfjord. Next door, a building is established for the new electric-powered 6 MW heat pump. The investment does not affect the heating price for Aalborg Utility's heating customers. Together with the ambitious national climate goals, the UN Sustainable Development Goals provide the line of sight for Aalborg Supply's work. "The investment in heat pumps contributes to a sustainable society. Because when we use the heat in the wastewater, we help to produce sustainable energy, reduce CO2emissions and become climate neutral," explains Lasse Frimand Jensen.
Overall, the water division with energy utilization via the heat pump on the discharge from Wastewater Treatment Plant East is not just climate neutral - but climate positive. The plant is a joint project between Aalborg Utility's water and energy division and is expected to be put into operation by the end of 2023.
150 MW electricity boiler capacity and 200,000 m3 heat storage at Nordjyllands power station
In addition to the heat pump at Wastewater Treatment Plant East, Aalborg Forsyning invests in 150 MW of electric boilers and a heat storage of 200,000 m3 in steel tanks. Both will be located at The North Jutland Power Station. Overall, the heat pump and boilers can produce 15% of the expected heat production in Aalborg Forsyning annually.
By establishing additional production capacity and a heat storage, Aalborg Forsyning gets flexible heat production and also ensures the tip and reserve load capacity of the future. At the same time, it is a step towards being able to phase out natural gas and strengthen Aalborg Utility's green profile. For example, the investment helps to future-proof the area at Nordjyllandsværket as a green test centre for new forms of energy. "Both technologies are proven, have long lifespans and the possibility of expansion as needed. Furthermore, the investment does not affect the heating price for Aalborg Utility's heating customers. At the same time, with the warehouse, we improve security of supply for the citizens, so that there is always warm tap water and a comfortable temperature in the living room," concludes Per Clausen.
The boilers are expected to be put into operation on 1 January 2024, while the tanks will be ready in 2022-2023.