Hyperscale data centers generate enormous quantities of waste heat – a physical byproduct long regarded as an unavoidable cost factor. With the amendment of Germany's Energy Efficiency Act (EnEfG) in 2026 and the European Energy Efficiency Directive (EED 2023/1791), the perspective has fundamentally shifted: waste heat is now a regulatory-relevant and economically exploitable resource. For infrastructure owners who hold data centers in their own portfolio, this opens strategic opportunities that extend far beyond mere compliance.
Regulatory Framework: EnEfG and the EU Energy Efficiency Directive
Since July 1, 2026, Germany has imposed binding requirements on waste heat utilization for new data centers with a non-redundant rated power of at least 300 kW. The minimum quotas for the Energy Reuse Factor (ERF) increase progressively:
- From July 1, 2026: 10% of energy consumed must be reused as waste heat
- From July 1, 2027: 15% minimum quota
- From July 1, 2028: 20% minimum quota
Non-compliance can result in fines ranging from €50,000 to €100,000. In parallel, the EU Energy Efficiency Directive requires operators of data centers with a rated power exceeding 1 MW to conduct a cost-benefit analysis for waste heat utilization and to report annually to national authorities.
These regulatory requirements are not an isolated German phenomenon: France has introduced binding obligations through Law No. 2025-391, Switzerland enforces cantonal requirements for facilities generating more than 2 GWh of waste heat, and the United Kingdom's Energy Act 2023 enables local authorities to mandate connections to heat networks in designated zones.
Technical Foundations: Temperature Levels and Cooling Concepts
The technical challenge of waste heat utilization lies in the temperature level. Conventionally air-cooled data centers generate waste heat at 25 to 45 degrees Celsius – too low for most third-generation district heating networks, which require temperatures between 70 and 90 degrees Celsius. Large-scale heat pumps can bridge this temperature differential but require additional electricity input.
Modern liquid cooling systems – particularly Direct Liquid Cooling (DLC) and immersion cooling – enable waste heat temperatures of 50 to 65 degrees Celsius and above. These technologies are compatible with fourth-generation district heating networks operating at lower temperatures and can often eliminate the need for heat pumps entirely.
For hyperscale data centers running AI workloads, liquid cooling is increasingly mandatory regardless: modern GPU clusters based on Nvidia's Blackwell architecture generate power densities of 40 to 100 kW per rack, which cannot be managed with air cooling. Investment in liquid cooling thus simultaneously serves operational stability and waste heat utilization – a dual strategic advantage.
Economic Potential: From Compliance to Value Creation
Infrastructure costs for waste heat recovery on the data center side typically range from €400,000 to €700,000 per megawatt (heat exchangers, piping, pumps). Payback periods vary between two and fourteen years depending on the distance to the heat network and the required temperature lift.
The revenue model is decisive for economic assessment: data centers can market waste heat to local district heating utilities through Heat Purchase Agreements (HPAs). Alternatively, waste heat utilization reduces the energy demand for conventional cooling, thereby lowering operating costs. For infrastructure owners who hold data centers in their portfolio over the long term, waste heat utilization represents a stable cash flow component that operates independently of short-term market cycles.
European pioneers demonstrate the scalability of this approach: in Stockholm, approximately 30 data centers feed waste heat into the city's district heating network. In Finland, waste heat recovery projects by Microsoft and Google cover up to 40 percent of regional district heating demand, supplying approximately 250,000 people. In Germany, the collaboration between Mainova and NTT DATA in Hattersheim has been supplying heat to over 600 households since late 2024; Berlin's "Neues Gartenfeld" project is set to supply approximately 4,500 apartments from late 2026.
Site Planning: Waste Heat Utilization as a Decision Criterion
For infrastructure owners developing new hyperscale sites, waste heat utilization is today an integral planning criterion – no longer an afterthought. Economic viability depends significantly on the distance to the nearest district heating network: projects within a two-kilometer radius typically achieve payback periods of under five years.
This translates into concrete requirements for site selection:
- Proximity to urban heat networks: Urban sites or peri-urban industrial areas with existing district heating infrastructure offer the best conditions
- Municipal cooperation: Early coordination with municipal utilities and local heat suppliers creates long-term offtake security
- Regulatory compliance by design: Integrating waste heat utilization from the outset into building and cooling planning avoids costly retrofits
- Permitting advantages: Municipalities that recognize waste heat as a contribution to local heat supply frequently demonstrate greater willingness to approve data center projects
ArcTeron: Waste Heat Utilization as Part of the Infrastructure Strategy
ArcTeron develops and holds hyperscale data centers in its own portfolio, targeting 5 GW of capacity across Europe. As an infrastructure owner and energy partner, ArcTeron has the prerequisites to integrate waste heat utilization as a strategic component of every site concept from the first planning phase.
The combination of a long-term own-and-hold strategy and integrated energy expertise – encompassing grid connection, gas supply, and renewable energy – enables ArcTeron to treat waste heat utilization not as a compliance obligation but as a value creation element. Heat Purchase Agreements with local utilities generate stable revenue streams; integration into municipal heat networks strengthens social acceptance and accelerates permitting processes.
Outlook: Waste Heat as an Infrastructure Asset of the Future
Regulatory requirements for waste heat utilization will continue to increase in the coming years – both in Germany and across Europe. For infrastructure owners who invest today in the appropriate cooling concepts and heat transfer systems, a lasting competitive advantage emerges: lower operating costs, additional revenue streams, and a stronger positioning vis-à-vis municipalities and regulators.
The transformation of waste heat from cost factor to strategic asset is not a future scenario – it is already happening today in Stockholm, Helsinki, Frankfurt, and Berlin. Hyperscale data centers that actively shape this transition will become integral components of Europe's urban energy infrastructure.
ArcTeron develops and holds hyperscale data centers in its own portfolio and is active as an energy partner in grid connection, gas supply, and renewable energy. Further information: arcteron.ai