Large pit heat storage on the way to the sizeable district heating areas

Date: 09/10/2020

Giant pond heat stores must store green electricity as district heating

Storage of heat both seasonally or more short term is getting really hot in Denmark. The unpredictability of electricity, the vast amount of surplus heat from other sources increases the need to separate time of production and time of consumption.

There is large pit heat storage on the way to the large district heating areas. In Høje Taastrup, a 70,000 cubic meter storage is being built, while Fjernvarme Fyn is planning a basin of 500,000 cubic meters, which will thus be the world's largest.

In Aalborg, there is also a new giant pit storage on the way. It may be ready by the end of 2022.

The project is dimensioned as two storages of 500,000 cubic meters each and will store 45,000 MWh and charge and discharge with 300 MW thermal power.

- Each of the two upcoming storages in Aalborg will be 2,5 times larger than the largest pit heat storage in Denmark to date, and since there are no similar storages abroad, the Aalborg project will thus be the world's largest of its kind, says project manager Christian Teil Fyhn from Rambøll Energi.

He estimates that the reason why there are so many new large storages is due to the fact that an increasing amount of varying renewable energy production on the electricity side must be accommodated. How large sea water heat pumps are obvious to transfer heat to a large pit heat storage, so you can store it for later in the year.

Aalborg Forsyning would like to receive ready-made offers before the end of the year. And if the utility company decides to proceed with the project, it can start as early as next year, which means that the plant can be ready in December 2022.


Read more about the use of heat storages in a more strategic and short-term way in these articles: - The Høje Taastrup project - about heat storage in general
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