Potential of aquifer thermal energy storage (ATES) for data centres in Germany

Overview

Data centres produce large quantities of waste heat and require excessive amounts of cooling, which offers potential for an environmentally friendly space-heating supply for nearby areas. This coupled supply suffers from a seasonal mismatch, with most space heating needed in winter while data centres produce heat all year. Aquifer thermal energy storage (ATES) is a cost-efficient way to overcome it. Germany has passed a law making examination of waste-heat utilisation mandatory for future data centres, and from 2026 newly installed heating systems in buildings must use at least 65% renewable heat.

Method: nominal capacity of air-cooled chillers with small (< 1 m) condenser fans was estimated as Qth = 53.3 × n kW (n = number of fans), a regression on 527 chillers. Annual waste heat available for storage was computed as Eth = Qth × F_load × (1 − F_free) × (1 − F_down), with a conservative mean annual load factor of 0.6 (60% of peak). The 19 data centres examined produce 1740 GWh_th of waste heat, but only 13 are on very well or well-suited subsurface for ATES outside regulated water-protection zones.

Assuming a 60% ATES thermal recovery rate, the 13 sites could supply 707 GWh_th, covering about 20,000 nearby buildings in Berlin, Düsseldorf, Frankfurt, Hamburg and Karlsruhe. In Frankfurt, six data centres on suitable ground could supply 541 GWh_th (13% of residential and commercial heating demand), and placing ATES for all ten Frankfurt sites in the most suitable areas could reach 819 GWh_th (20%).

Limits: the waste-heat estimate rests on chillers detected on aerial images and generic load factors, not measured data; not all of the 19 data centres suit ATES, and the thermal recovery is a 60% assumption.

Key points

1. Germany has passed a law making examination of waste-heat utilisation mandatory for future data centres, and from 2026 newly installed heating systems in buildings must use at least 65% renewable heat.
2. Nominal capacity of air-cooled chillers with small (< 1 m) condenser fans was estimated as Qth = 53.3 × n kW (n = number of fans), a regression on 527 chillers.
3. Annual waste heat available for storage was Eth = Qth × F_load × (1 − F_free) × (1 − F_down), with a conservative mean annual load factor of 0.6.
4. The 19 data centres examined produce 1740 GWh_th of waste heat, but only 13 are on very well or well-suited subsurface for ATES outside regulated water-protection zones.
5. Assuming a 60% ATES thermal recovery rate, the 13 sites could supply 707 GWh_th, covering about 20,000 nearby buildings in Berlin, Düsseldorf, Frankfurt, Hamburg and Karlsruhe.
6. In Frankfurt, six data centres on suitable ground could supply 541 GWh_th (13% of residential and commercial heating demand); ATES for all ten sites in the most suitable areas could reach 819 GWh_th (20%).

Using it in design

• Before linking data-centre waste heat to nearby building heating, check that site subsurface geology suits ATES and that the site is outside water-protection zones; only 13 of 19 sites did.
• Calculate waste-heat potential from installed chiller capacity, load factor (0.6), free cooling and downtime, and make the ATES thermal recovery rate (60%) an explicit input.
• Bridge the seasonal mismatch (year-round heat, winter-peaking demand) with ATES and match it to nearby building heating demand.

Who should read it

Planners, and geothermal and energy engineers planning to link data-centre waste heat to nearby building heating through seasonal storage.

Document contents

1. Introduction
2. Methods (chiller detection on aerial images, cooling-capacity regression, waste-heat calculation, ATES suitability analysis, matching to heat demand)
3. Results (waste heat of 19 data centres, sites suited for ATES, Frankfurt case)
4. Discussion and conclusions

Related standards

• German Energy Efficiency Act (EnEfG)
• GEG (65% renewable heat rule)

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Publication details

Authors

Florian Barth; Georg Schefel; Philipp Blum; Kathrin Menberg

Publisher

Geothermal Energy (Springer Science and Business Media LLC)

Year

2026

Volume

14

Issue

1

Pages

11

Document language

English

Source type

Scientific

Access

Open licence — downloadable

DOI

10.1186/s40517-026-00383-8

Licence

CC BY 4.0 — share with attribution

Licence evidence

doi.org

Citation