NGLL: Aquifer Storage | TECHNISCHE-THERMODYNAMIK

Planning and construction of an aquifer storage for the seasonal storage of waste and excess heat

Project: Aquifer Storage

Problem Statement

The heat supply of the Free and Hanseatic City of Hamburg will have to change due to the accelerated heat transition. New heat sources from renewable energies (e.g. solar thermal, PtH from wind power, biomass) and CO₂-neutral feed sources (waste heat from industrial processes) must be developed and integrated into the district heating system. Outside the heating period, the absorption capacity of the district heating system remains below the feed-in potential of climate-neutral waste heat sources, which otherwise remain unused. However, the seasonal offset between supply and demand in the heat sector is a crucial problem for the implementation of the heat transition, which the aquifer storage addresses.

Project Goal

With the construction and operation of a demonstrator, the project intends to show the technical and economic feasibility of an aquifer storage facility in a large-scale test and develop optimization measures with operating data. With a storage capacity of 2.6 MW, a capacity of 5 GWh and a storage depth of 1000m, the aquifer storage facility is the largest high-temperature storage facility in the world. By using an aquifer storage as a seasonal heat storage, the unused feed-in potential can be shifted from the summer months to the heating period. This significantly increases the proportion of CO₂-neutral heat in the district heating system and saves up to 34,000 t of CO₂ over the service life of the storage facility.

Project Approach

Construction and commissioning of a high-temperature aquifer storage facility at a depth of 1000m and its integration into an existing district heating network. This is followed by a demonstration operation in which the storage operation is comprehensively recorded by measurement and an optimal operation of the storage is examined. The figure below shows the basic functional principle of an aquifer storage facility.

Responsibility of TUHH

The planning and construction of the aquifer storage is to be accompanied scientifically. The Institute of Engineering Thermodynamics is to map the dynamic operation of the storage facility and to validate the entire system with the help of a detailed measuring system of the above-ground facility. The overall system consists of the actual underground storage facility and the surface facility. This overall model should then be used to optimize storage management.

Classification in NGLL

In the transnational joint project, the holistic transformation of the energy system can be tested. For that, the focus is on two technology areas: integrated sector coupling with main focus on hydrogen as well as energy-efficient district solution in the field of heat. By creating sustainable innovations in the sector coupling through large and scalable demonstrators economic impulses for the development of future markets can be provided, especially in the industry and its value chains. The aim is also to secure and expand the industrial location Northern Germany as well as the strengthening of future viability and competitiveness of local companies. Ultimately, the realistic testing of the transformation path towards a secure, integrated energy system with the decarbonization goal of reducing CO₂ emissions in the region by 75 percent by 2035 shall result.