Pit thermal energy storage in Roskilde

Balmorel: Power system model | June 2020 - March 2022

In this project Ea Energy Analyses participated in a pre-feasibility study on whether investing in a pit thermal energy storage (PTES) in Roskilde would be financially attractive. The district heating network in Roskilde is connected to the joint district heating network in the Greater Copenhagen area via VEKS, and the interaction with the joint system was analysed as part of the project in the energy systems model Balmorel. In parallel with the system analyses, Rambøll carried out analyses of the technical and economic consequences of different options for connecting the PTES to the district heating grid in Roskilde.

Ea Energy Analyses examined the reduction of system costs and the size for the potential PTES in Roskilde. The analyses were carried out for the years 2025-2040. The work included setting up scenarios and key assumptions, load dispatch calculations, analysis of storage capacity and volume, analysis of reduction of system costs, and division of the benefit of the storage to the different stakeholders in the system.

The pre-feasibility study was carried out under the auspices of the regional energy project Energi på Tværs, where a separate purpose was for the PTES project to contribute with knowledge and inspiration for establishing other thermal storages in the Greater Copenhagen area.

The project ran from June 2020 to February 2021 and was carried out for Gate21.

Additional analyses

District heating company VEKS subsequently continued the projekt and asked Ea Energy Analyses for some additional sensitivity analyses to illuminate further aspects of the project. This included, among other things

  • a change in electricity prices
  • a different way of connecting the pit thermal energy storage to the district heating network
  • combined establishment of a pit heat thermal storage and an electrical boiler in Roskilde

This project ran from May 2021 to March 2022.