Heat Reuse Outlook

Author: Cosimo (outgoing co-lead, compute company), Baharat (incoming co-lead, Microsoft); additional contributors including David (NRL, Reference Designs workstream), Peter and Jack (TCO analysis workstream), David and Otto (Policies workstream) Collection: 2023 Global Summit - Cooling Environments

Summary

This presentation provided an annual update from the OCP Heat Reuse sub-project, the youngest sub-project under the Cooling Environments umbrella, now approximately two years old. The session covered the sub-project's structure, outputs to date, the global heat reuse map, and three new workstreams (Reference Designs, TCO Analysis, and Policies) that were launched to produce concrete deliverables by Q2–Q3 2024.

The sub-project's core insight is that northern Europe is far ahead of North America in heat reuse adoption, due to pre-existing district heating network infrastructure, higher population density enabling nearby heat consumers, political incentives, and in some jurisdictions explicit legal requirements (Germany legislation mandating 10% heat reuse from data centers). The group gathered over 25 guest presentations from global heat reuse practitioners, most from northern Europe (Sweden, Finland, Denmark, Netherlands), and published the "Heat Reuse 101" white paper as a foundational guide covering data center location and size as primary drivers of heat reuse opportunity, temperatures, and other technical factors.

A living global heat reuse map (accessible via QR code) catalogs operational and under-construction heat reuse projects worldwide. The map shows a stark asymmetry: the majority of operational projects are in northern Europe, with far fewer in North America. Microsoft's Baharat announced a specific project: the Helsinki, Finland data center will share waste heat with the Fortum district heating network starting summer 2025, capturing the equivalent of 400,000 metric tons of CO2 per year by sharing low-grade waste heat (30–35°C from air-cooled facility water, with liquid cooling expected to increase this to 40–45°C or higher). The heat pump station in this case is owned by Fortum (the utility), not Microsoft — a demarcation point model the group is examining for broader applicability.

The three workstreams under development target: (1) a reference design and dimensioning tool for a heat reuse room/heat exchanger interface between data center and heat host (white paper expected Q2–Q3 2024, led by David from NRL); (2) a TCO financial model with pre-built scenarios for air-cooled vs. liquid-cooled data centers and various heat applications (greenhouse, district heating, etc.) led by Peter and Jack; and (3) a policy analysis and best practices white paper aimed at reaching decision makers and legislators, led by David and Otto. Additional future deliverables include a checklist for existing data centers to assess heat reuse readiness, and a "matchmaking platform" (described as "Tinder for data center heat reuse") connecting heat generators with heat consumers.