The GeoHeatStorage part of the smood “smart neighborhood” initiative delivers a large‑scale, low‑cost seasonal heat storage system that relies on the geological subsurface rather than conventional container or borehole storage. The project’s core objective was to define site‑specific suitability criteria for the use of aquifer‑based storage, embed these criteria in a geographic information system (GIS), and from the resulting geological and engineering constraints derive a preliminary plant design. The design process also incorporates the required storage capacity for a whole neighbourhood and outlines the necessary investigation and simulation steps.

A key technical deliverable was the development of a cost‑of‑construction tool for the subsurface component of the GeoHeatStorage system. This tool was merged with an existing surface‑component cost model to produce a unified cost calculator. The integration enabled a probabilistic economic analysis that identified the main cost drivers and quantified their impact on the overall project economics. Using the cost model in conjunction with a geothermal simulator, the team established an optimisation routine that iteratively adjusts design parameters—such as borehole spacing, depth, and pipe diameter—to minimise total cost while meeting performance targets. The optimisation framework also feeds back into the GIS, allowing users to query potential sites and instantly see the projected cost and performance envelope.

The GIS was further evolved into a potential‑query tool that clusters geological data into suitability classes. By applying a clustering algorithm to lithological, hydraulic, and thermal parameters, the system automatically classifies prospective sites into high, medium, or low suitability. This classification is then overlaid on administrative boundaries, enabling planners to assess the feasibility of GeoHeatStorage for specific neighbourhoods. The tool also supports the generation of a standardised service product that can be offered to developers and municipalities.

A demonstration project was prepared to validate the concept in a real urban setting. The prototype plant concept was defined, including the layout of surface infrastructure, the arrangement of subsurface boreholes, and the integration with existing district heating networks. The demonstration was scheduled for 2023/24, following the project’s completion conference in December 2022, which showcased the finished results to government officials and industry stakeholders.

Collaboration within the smood consortium was coordinated by JENA‑GEOS, which acted as the entrepreneurial alliance spokesperson. The consortium included a mix of research institutions, engineering firms, and local utilities, all contributing expertise in geology, GIS, thermal simulation, and cost modelling. The project was funded through a regional growth‑core initiative, with the German federal and state governments providing the financial support that enabled the research and development activities. The consortium’s public relations efforts, managed by smood e.V., ensured that the outcomes were communicated to policymakers, potential customers, and the broader public, thereby strengthening the market position of the participating small and medium‑sized enterprises. The project’s timeline spanned from initial geological assessment to the final demonstration, culminating in a conference that highlighted the readiness of the GeoHeatStorage technology for commercial deployment.