TREASURE project

With the growing need for energy system fl exibility and the rise of renewable energy sources like solar and wind, thermal energy storage becomes essential to balance supply and demand. The EUfunded initiative, TREASURE, aims to utilize the potential of Pit Thermal Energy Storage (PTES) for district heating networks and accelerate the adoption of large-scale PTES solutions to phase out fossil fuels and establish 100% renewable district heating systems across Europe.

A fully decarbonised European energy system requires significant capacity for heat storage to accommodate the fluctuating availability of renewable energy. PTES systems off er a unique solution, maximizing the storage of solar, geothermal heat or waste heat during warmer periods and deploying it when demand rises. TREASURE's core goal is to develop robust, safe, and cost-effective PTES solutions that are scalable across Europe's diverse climatic zones.

Through the targeted development of components, integration processes, and collective improvements in design and building protocols, TREASURE brings together a wide group of experts and market-driven partners to develop scalable and secure methodologies for implementing PTES systems.

A central focus of TREASURE is to demonstrate robust, safe, and economically viable PTES solutions across Europe. The project is developing and monitoring seven large-scale PTES demonstrations in five countries, with storage capacities ranging from 18 000 m³ to 500 000 m³. These sites provide different geographical conditions, including the local environmental and energy source variations. Importantly, economic competitiveness is prioritized, ensuring the PTES systems are financially attractive to district heating companies. Apart from technology, social acceptance is crucial, and TREASURE is actively studying how different countries across Europe view large-scale thermal energy storage to develop measures that encourage public and policy-maker support.

To ensure scalability and replication there is a need to understand that achieving fully renewable heating systems will require efficient design, smart integration of energy storage, and cost-effective deployment. To that end, TREASURE works closely with more than 15 satellite initiatives across Europe. These partnerships ensure the rapid transfer of knowledge, best practices, and support for permitting and financing challenges. Plans to increase societal acceptance are also integral, helping ensure a successful adoption of PTES systems. Working closely with the satellite initiatives is the basis for an effective spread of the experiences in the project, and a source of direct interactions leading to better quality and application of the project developments and achievements. All new PTES initiatives are kindly invited to join the existing group, strengthening the corporation and learning from the collaboration.

Additionally, TREASURE aims to develop smart system integration concepts that maximize the share of renewable heat in district heating networks. This will involve developing secure thermal energy storage systems that can interface seamlessly with broader heating infrastructures. By improving these systems, district heating companies will be able to address operational challenges related to peak demand and fluctuating energy supply. Key to this process will be monitoring data from existing systems, which will help simulate future performance and optimize the design and function of new systems.

The duration of the whole process, from idea through planning, design, building, to commissioning and operating, is very long at the moment, up to seven years. To get better grips on this process, a number of internal workshops are organised, each addressing one of the main phases in the project. After the first workshops, we can already identify a number of challenges that, when addressed, would lead to a shortening of the project duration. One of these is a lack of experience with the new technologies with officials involved in permitting and legislation. In the further course of the project, a dedicated workshop for permitting and legislation is planned. People interested in this are invited to get into contact with us.

Whether it's overcoming regulatory hurdles in France or addressing environmental challenges in Serbia, TREASURE stands as a unique initiative increasing awareness and implementation of renewable, efficient, and user-accepted PTES systems that can play a crucial role in Europe's energy transition.