Development of short time and seasonal energy storage

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Høje Taastrup District Heating and COWI A/S have examined the potential of a short time and seasonal energy storage in the municipality of Høje-Taastrup. The storage will be established as an ATES plant. Uffe Shleiss from Høje Taastrup District Heating summarizes the findings.

What is the main purpose of the deliverable?

The deliverable has the purpose to examine the possibilities to develop a short time and seasonal energy storage, in the shape of an Aquifer Thermal Energy Storage (ATES) plant that can be integrated in the LTDH system in the municipality of Høje Taastrup, Denmark.

In addition, the deliverable describes two options for heat storage ponds

What are the main findings in your studies?

We base the findings on the first exploratory drillings and simulations made by the contractor GEO. GEO performed simulations on one pair of boreholes and three pair of boreholes. The simulations showed that one pair of boreholes would ensure a satisfying operation: the cold well and the warm well would not influence each other with respect to temperature. Moreover, the groundwater level would revert to normal after ending of operation. The simulation with three pair of boreholes showed that the two wells would influence each other with respect to temperature and is not recommended.

GEO recommended establishing and maintaining an ATES plant with a flow in wintertime of 68 – 130 m³/h and in summertime of 94 – 180 m³/h. In practice, this we can do this by establishing two pair of boreholes and pumps with an average flow of 2 x 54 m³/h in winter and 2×75 m³/h in summer. GEO furthermore assessed that an ATES plant with the recommend flow will not influence any protected nature areas or nearby properties. Finally, the ATES plant will not have any negative impact on the water quality in any areas where tap water is extracted.

When it comes to the two different options for heat storage ponds, we looked at:

  1. A heat storage pond of at least 70,000 m³ intended for optimizing the use of lost cost operating heat production plants. The plant is able to store at least 3,300 MWh of heat.
  2. A test pond – either built separately or combined with the pond above – which will exchange approximately 115,000 MWh of heat annually.
The heat storage pond is constructed by digging a pit and pile up the excavated soil at the side.

The heat storage pond is constructed by digging a pit and pile up the excavated soil at the side. Source: Beskrivelse af damvarmelager ved Klevehøjvej ved Høje Taastrup, PlanEnergi, 2017.

What happens now?

We are establishing the first set of boreholes and making it operational. We are also combining the ATES with a 1 MW heat pump. This will make it possible to have more operation hours on the heat pump.

In two weeks we will make a final investment decision about establishing a 70.000 m3 pit pond storage linked to the transmission system.

Read the report

Since this is a confidential report, you will not find it for download. However, if you are interested in learning more, please contact Uffe Schleiss on Høje-Taastrup District Heating: