Lappeenranta city: Thermal energy battery for the district heating network

In this action, a new type of energy battery will be purchased and installed to the district heating network of Mustola, Lappeenranta. The network, where the battery will be connected, is separate district heating network that is today operated by 10 MW natural gas and light fuel oil. The network is separate from city network and it is not included in emission trading district heating network.

The objective of this action is to reduce emissions in the heat production for buildings with a help of a novel energy storage technology. Additionally, the usage of this technology supports the expansion of low carbon energy sources, namely, solar, wind, nuclear and water power. Also, same technology could be further applied in steam production and cooling at later stage.

Energy battery technology is based on the phase conversion of a material. The battery is heated by low cost - low carbon electricity produced either wind, solar, CHP biomass or nuclear energy. The battery is then discharged to the district heating network when heating is needed. The new technology that is based on phase conversion decreases oil and natural gas usage and therefore GHG emissions as well in district heating.

Besides efficiency in the district heating network, the implemented technology provides frequency regulation and reactive power compensation services to power grids. Furthermore, increase of this service capacity creates a possibility for additional investments for renewable electricity production.

Cost and emissions reductions with heat storage

Expectation is that the solution will decrease CO2 emissions 300–400 ton/CO2e annually at Mustola site if operated continuously. By this solution the heating energy can be produced cheaper than with natural gas and oil at Mustola case. Solution requires also less maintenance compared to boilers.

Time frame

  • Procurement of the energy battery: Q1 2019
  • Installation of the equipment: Q3 2019
  • Testing of the battery: Q3 2019–Q3 2024


More information

  • Director Ilkka Räsänen, City of Lappeenranta,, tel. +358 400 815 284
  • Climate coordinator Petri Kero, City of Lappeenranta,, tel. +358 40 6530 508
Published 2019-02-19 at 13:07, updated 2024-05-24 at 13:41

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