New demonstration plant: Aalborg Forsyning invests in thermal salt storage

Nordjyllandsværket A / S has just entered into an agreement with the Norwegian Kyoto Group on establishing a thermal battery that can convert electricity from wind turbines and store it as heat until there is a need for it in the district heating network.

- Renewable energy sources are unpredictable. They only produce energy when the sun is shining, and the wind is blowing, which creates large fluctuations in prices. But with the new demonstration plant at Nordjyllandsværket, when it is very windy, and wind energy is cheap, we can store it and store it as heat. Therefore, the plant will be another essential step in the green transition and the phasing out of fossil energy sources such as coal, says Lasse Olsen, chairman of Nordjyllandsværket A / S.

In short, the demonstration plant uses wind energy to heat salt to 525 degrees and molten salt to form steam, which exchanges heat with the district heating system, whereby the heat enters into the district heating network. The technology is used in Southern Europe to store solar energy. Still, it is the first time that molten salt technology has been used in Denmark to store surplus electricity from wind turbines as heat for later use in a district heating network.

First demonstration facility of new test center

Today, the area, which houses Nordjyllandsværket, is being transformed into a green test center. With its location very close to the production at Nordjyllandsværket, it can help develop and test new supply solutions and improve the solutions already used today.
- In Aalborg Forsyning, we want to play an active role in developing and testing the green solutions of the future. The thermal battery from Kyoto Group will be the first demonstration facility in the Green Test Center, so for both us and Kyoto Group, this is an important milestone. We see excellent prospects in the solution, but in the first instance, we would like to test and verify that it works in connection with district heating, says Søren Gais Kjeldsen, CEO of Aalborg Forsyning.

HeatCube in practice

Kyoto Group is pleased with the agreement with Nordjyllandsværket A / S, and CEO Christopher Kjølner is looking forward to testing the thermal battery, which the company has chosen to call HeatCube, in practice:

- This is our first commercial agreement with HeatCube, and we look forward to supplying heat to the district heating network in Aalborg and thus helping to phase out the use of coal. HeatCube is a scalable storage system, and we see great potential to expand the installation over time.
The demonstration plant at Nordjyllandsværket will have an annual energy volume of 5000 MWh, corresponding to the annual heat consumption in approximately 250 single-family houses.

The plant is to go into operation in the second quarter of 2022.

Translated from the Danish article "Aalborg Forsyning afprøver lagring af grøn energi som varme" published at Aalborg Forsyning, November 22th, 2021