Underground Thermal Energy Storage in Dense Urban Areas – EU-Wide Advantages and Opportunities

1. Single Market Access

- Direct route to a 450 + million-citizen market where building renovation, district-heating expansion and heat-pump uptake are politically mandated under the EU Renovation Wave and RePowerEU.

- One CE-mark, one Ecodesign/EPBD compliance process: once technical conformity is proven, UTES components (heat exchangers, control units, monitoring sensors) can be traded across 27 Member States without additional national certification.

- Pan-European public-procurement instruments (e.g. joint cross-border Green Public Procurement, Innovation Partnerships) make it possible to bundle demand from multiple cities, reaching economies of scale that drive the Levelised Cost of Heat Storage (LCOHS) below the tender threshold of most municipal utilities.

2. Cross-Border Collaboration

- Consortia can combine complementary geological settings (karst in Southern Europe, sedimentary basins in Benelux, crystalline rock in Nordics) to create a knowledge base covering virtually all EU subsurface typologies, boosting replicability scores in the Horizon evaluation.

- Access to established trans-national research infrastructures such as EPOS, EuroGeoSurveys and EERA Geothermal shortens data-collection times and opens huge, FAIR-compliant datasets.

- Cities networked via Eurocities, Energy Cities and the Mission for 100 Climate-Neutral Cities offer living-lab sites where legal, social and technical lessons travel instantly across borders.

3. Alignment with EU Flagship Policies

- Green Deal & Fit-for-55: UTES directly tackles heating and cooling, one of the hardest-to-abate sectors, helping deliver the 49 % renewable-heat target by 2030.

- Sustainable & Smart Mobility Strategy: integration with metro tunnels, rail cut-and-cover slabs and underground car parks turns transport infrastructure into energy assets.

- Digital Europe & Data Governance Act: the topic’s digital-twin and open-data requirements dovetail with EU cloud and data-spaces initiatives, facilitating additional funding from DEP (Digital Europe Programme).

4. Regulatory Harmonisation Benefits

- The 2024 recast of the Renewable Energy Directive (Art. 24a) formally recognises thermal storage; project results can feed directly into the upcoming delegated acts, influencing EU-wide permitting rules.

- Pre-standardisation work with CEN/TC 451 (water-energy in the underground) offers early-mover advantage and speeds certification of new borehole materials or monitoring fibres across the EU.

- Uniform application of the Environmental Impact Assessment and Soil Directive means one methodology for subsurface risk management instead of 27 different ones.

5. Access to Europe’s Innovation Ecosystem

- Synergies with 3 000 + HEU energy projects, 11 Knowledge and Innovation Communities (EIT), 40 Digital Innovation Hubs focused on built environment and geothermal.

- Talent pipeline: Marie Skłodowska-Curie DN can second young researchers to demo sites, while Erasmus Mundus Joint Masters can embed UTES modules, ensuring skills availability EU-wide.

- Test beds such as Living Labs of JPI Urban Europe and the European Urban Initiative offer ready-made frameworks for citizen engagement and SSH integration demanded by the call.

6. Funding Synergies and Blending Opportunities

- Cohesion Policy (ERDF) and Just Transition Fund can co-finance large civil-works CAPEX in less-developed regions after Horizon proof-of-concept.

- LIFE Clean Energy Transition grants cover replication and market-uptake activities post-project, de-risking commercial roll-out.

- CEF Energy window (cross-border district-heating interconnectors) and InvestEU sustainable infrastructure window offer debt/guarantee instruments to scale UTES clusters.

- EIC Pathfinder/Transition can spin off high-risk monitoring or drilling technologies that emerge during the project.

7. Scale and Impact Potential

- 75 % of EU citizens live in urban areas; even a conservative 5 % penetration of seasonal UTES by 2035 represents >50 TWh of storage capacity and avoids ~12 Mt CO₂/yr.

- Harmonised business models (heat-as-a-service, thermal PPA templates) can be disseminated through EU city networks, accelerating uptake far beyond the initial demonstrators.

- Creation of an EU-level SUHI monitoring platform (mandated in the call) positions Europe as the global reference for urban geothermal analytics.

8. Additional Strategic Value of Operating at EU Level

- Risk pooling: geological, market and social risks are diversified across multiple Member States, increasing bankability for subsequent commercial projects.

- Political visibility: success stories feed into Mission Climate-Neutral Cities progress reports, amplifying policy support and unlocking further national co-funding.

- Export readiness: compliance with the strictest EU environmental and safety standards provides a strong credential for global markets (e.g. North America, Japan) where urban geothermal is nascent.

9. Actionable Opportunities for Proposers

- Build a tripartite consortium: (1) Nordic/Baltic partner for high-temperature BTES, (2) Central European city with existing district heating for mid-temperature ATES, (3) Mediterranean coastal metropolis to validate low-temperature CTES in cooling-dominated climate.

- Integrate a CEN working-group rapporteur and a national geological survey as formal partners to fast-track standardisation and data interoperability deliverables.

- Allocate lump-sum budget for a pan-EU citizen jury programme (10 cities, translated materials) to exceed the SSH/citizen-engagement threshold and gain evaluation points.

- Pre-agree with managing authorities of two ERDF Operational Programmes to funnel structural-fund money into post-Horizon replication, demonstrating scalability in the proposal.