Meta Odense, Stockholm Exergi, Microsoft Espoo: three pioneers in numbers
45 MW, 215,000 MWh/year, >12,000 households: robust KPIs from three European reference projects.
TL;DR
- Meta Odense: ~45 MW installed, ~215,000 MWh/year, more than 12,000 households supplied.
- Stockholm Exergi: > 100 GWh/year from 20 suppliers; target 10 % of the city's heat demand.
- Microsoft / Fortum Espoo: ~40 % of the district heating demand of 250,000 people; start planned ~2026.
- All three projects rely on heat pumps for temperature lifting.
- The key is a long-term partnership with the local network operator — not the technology alone.
1. Background
That data-centre waste heat can be scaled into district heating networks is no longer hypothetical. Three European projects deliver robust KPIs — under different regulatory and climatic conditions.
2. Data
| Project | Installed capacity | Heat / year | Households served | Status |
|---|---|---|---|---|
| Meta / Fjernvarme Fyn, Odense (DK) | ~45 MW | ~215,000 MWh | > 12,000 | Operating since 2019 |
| Stockholm Data Parks (SE) | — total n/a | > 100 GWh (20 suppliers) | ~31,000 flats | Ongoing since 2014 |
| Microsoft / Fortum, Espoo (FI) | n/a | n/a | 250,000 inhabitants (40 % demand) | Planned ~2026 |
Sources: Ramboll / Fjernvarme Fyn; EnergiRaven; Aquatherm blog 2025
The Tietgenbyen Energy Center in Odense was Denmark's largest heat-pump project and the first to feed back waste heat from a hyperscale data centre at this scale. Stockholm Exergi has operated heat recovery since 1979 — and since 2012 under the "Open District Heating" model, supplying more than 800,000 people with heat.
3. Implications for municipalities and energy providers
All three projects share a structural feature: in each case the heat-network operator — Fjernvarme Fyn, Stockholm Exergi, Fortum — built and operated the heat-pump infrastructure. The data-centre operator supplies low-temperature heat and receives a cost contribution or network relief in exchange. For energy providers this means: the initiative must come from them. Those wishing to become an offtaker of data-centre waste heat need heat-pump capacity on their side — and a network expansion plan that structurally accommodates this source.
4. Where P2H connects
P2H explicitly targets smaller and mid-sized energy providers that cannot mobilise investment volumes of a Fjernvarme Fyn project. The modular 5 kW to 1 MW architecture creates entry points below the hyperscale threshold. The constraint is analogous: P2H modules also require a hydraulically connected offtaker on the provider side.
5. Outlook
In Ireland alone, data-centre waste heat could supply approximately 1.6 million households by calculation. The potential exists — the question is who organises and finances the system integration. The three pioneers show it works; they also show it does not succeed without structured partnership between data-centre operator and heat-network operator.
Sources
- Ramboll (2020/2023): Meta surplus heat to district heating, Odense. https://www.ramboll.com/en-us/projects/energy/meta-surplus-heat-to-district-heating
- EnergiRaven (2025): Stockholm's Open District Heating. https://www.energiraven.com/harnessing-excess-heat-lessons-from-stockholms-open-district-heating/
- Aquatherm blog (2025): Using waste heat from data centres. https://blog.aquatherm.de/en/using-waste-heat-from-data-centres-turning-digital-heat-into-community-warmth
- Stockholm Data Parks / DigiPlex (2018). https://stockholmdataparks.com/2018/03/12/digiplex-data-center-heat-10000-stockholm-households/