Current knowledge about large thermal energy storage systems is limited to a small number of implemented projects. In order to change this situation in the long term, a project team of 23 European researchers, technology providers, construction companies and heating network operators, led by the Styrian research institute AEE – Institute for Sustainable Technologies (AEE INTEC), has developed a project idea that will ensure robust, safe, cost-effective and sustainable thermal energy storage on a large scale in the future and has thus won the EU project “TREASURE – Novel large-scale thermal energy storage technologies in local and district heating networks” (Horizon Europe research program). Volume: 11 million euros.
Project content and objectives:
The aims of the project are to deliver innovations in the field of component and system development and thus enable a significant reduction in costs:
On the one hand, the research here focuses on building constructions for storage walls and storage covers that offer space-efficient solutions, particularly for urban areas, and can therefore be implemented despite the limited availability of space and high land costs.
In order to optimize construction processes, increase construction quality and reduce costs, a declared project goal is to extend the Building Information Model (BIM), which is well known in the building sector, to the requirements of large heat storage facilities.
The development of so-called “digital twins” of large heat storage tanks not only allows simulation-based optimization of the storage tank and system design during the planning phase, but also provides the basis for efficient operational management and control over the entire service life of the storage tank.
TREASURE also demonstrates the function and cost-effectiveness of the technology on the basis of 7 large-scale heat storage projects to be implemented during the course of the project. Close supervision of the planning, construction and, in some cases, plant operation (monitoring) guarantees the best possible knowledge gain and exchange within the project consortium and the interested industry.
The knowledge generated is to be made available to 14 other European projects for large-scale heat storage facilities (so-called satellite projects).
The main benefit of the project lies in mapping the functionality and economic viability of large-scale heat storage technology. The knowledge gained from the project will provide a broad information base and innovative solutions for investors, district heating operators, decision-makers, construction companies and engineers, which in turn will make an important contribution to accelerating the market growth of large water heat storage systems in Europe.
Seven concrete implementations of large-scale heat storage facilities in European cities:
A total of seven underground large-scale water heat storage facilities with volumes between 18,000 and 500,000 m³ are to be implemented in 5 European countries as part of the project, i.e. accompanied from planning and structural implementation through to operation. Heat from various renewable energies and industrial waste heat is stored in order to replace fossil-generated heat from coal, oil and natural gas. The 7 demonstrators are at different stages of planning and implementation, which is why some are scheduled to go into operation in 2026 and others in 2027. An overview of the key data and deployment situations of the 7 implementation projects is described below:
The seven demonstrators and their deployment situations at a glance:
Poland:
Large heat storage facility in Choszczno (25,000 m³)
Here, a coal-fired heating plant is being partially replaced by solar thermal energy and heat pumps. In future, the coal-fired heating system will only be used to cover peak loads. The storage facility is to be operated as a seasonal storage facility.
Large heat storage facility in Bytom (40,000 m³ – 100,000 m³).
The storage facility is to be operated bivalently using a compression heat pump and biomass heating plant and replace the use of coal.
Germany:
Large heat storage facility in Hechingen (18,000 m³)
The storage facility absorbs heat from solar thermal and geothermal energy in the summer months and feeds two compression heat pumps in the winter months. The peak load in winter is covered by a natural gas boiler system, a special feature of this project is that it was built in an old landfill site.
Large heat storage facility in Rostock (500,000 m³)
The storage facility is being built as part of a larger system with the integration of industrial waste heat and compression heat pumps. The overall system for the city of Rostock will include a total of five storage facilities, which will enable both short-term and long-term storage.
Serbia:
Large heat storage facility in Pancevo (200,000 m³)
The storage facility in Pancevo is charged using thermal solar energy and operated in conjunction with an absorption heat pump and a gas boiler.
France:
Large heat storage tank in Pau (350,000 m³)
Here, the storage facility is operated as a short-term and long-term storage facility and linked to industrial waste heat and a compression heat pump.
Austria:
Large heat storage facility in Vienna (40,000 m³)
Wien Energie is planning a 40,000 m³ storage facility based on ground source technology. The system should be connected to the primary district heating network. The charging and discharging strategy is based on the energy industry framework conditions and the characteristics of the generation portfolio.
The TREASURE project is led by AEE INTEC (project manager Dr. Wim van Helden) and involves a total of 23 project partners along the value chain
