Appendix · Sources & Methodology

Every claim, traceable.

This assessment was produced by Dossier, powered by the x1000 engine. Each external figure is cited by number to a third-party source below — click any to open the original.

How it was made

Fan out. Verify. Then write.

The engine

5 research angles -> 24 sources -> 113 extracted claims -> adversarial fact-checking (each claim survives a 2-of-3 or unanimous verifier vote) -> cited synthesis.

What got cut

8 of 25 tested claims were killed in verification and excluded. Every figure that remains is tied to a source that passed.

The honest caveat

This is secondary research — no primary interviews. Project-level economics should be confirmed against a specific site and offtaker before any capital commitment.

The reference list

12 sources, all clickable.

Technology & thermodynamics

1Experimental Lessons of an Organic Rankine Cycle for data-center waste-heat recovery (~2% conversion; net energy loser; ~40K differential needed)Vertiv (white paper) · https://www.vertiv.com/en-us/about/news-and-insights/articles/white-papers/experimental-lessons-of-organic-rankine-cycle/2Immersion-cooling outlet temperatures (~60°C) & district-heating-vs-ORC sitingApplied Thermal Engineering · https://www.sciencedirect.com/science/article/pii/S1359431124001479 3Coolant temperature & waste-heat recovery effectivenessJournal of Cleaner Production · https://www.sciencedirect.com/science/article/pii/S0959652624033213 4Dual-loop ORC techno-economics (heat-pump upgrading required)Applied Thermal Engineering · https://www.sciencedirect.com/science/article/pii/S1359431116326114 5Heat reuse: a management primer (recoverable grades; Germany EnEfG quota; EU EED >=1MW reuse-or-justify; no pricing mechanism)Uptime Institute · https://uptimeinstitute.com/resources/research-and-reports/heat-reuse-a-management-primer

Unit economics

6Allocation of investment costs for large-scale heat pumps (0.8-1.1 M€/MW; heat pump 38-54% of project cost)DTU / Pieper et al. (Energy Procedia) · https://www.sciencedirect.com/science/article/pii/S1876610218302613 7Data Center Waste Heat Reuse: An Investment Analysis (10MW Philadelphia <2-yr payback with carbon credits, excl. connection)ASME J. Eng. Sustainable Bldgs & Cities · https://asmedigitalcollection.asme.org/sustainablebuildings/article/6/1/011002/1210426/Data-Center-Waste-Heat-Reuse-An-Investment 8Göttingen waste-heat pricing & storage economics (~48-56 vs ~90-93 €/MWh; storage doesn't pay)Energy Conversion & Management · https://www.sciencedirect.com/science/article/pii/S0196890425003796

Operators in market

9Octopus Energy invests £200m in waste-heat data-center business Deep Green (Devon pool heating bill cut ~60%)DatacenterDynamics · https://www.datacenterdynamics.com/en/news/octopus-energy-invests-200m-in-waste-heat-data-center-business-deep-green/10Reclaiming data-centre waste heat nets Qarnot €35 million (Jan 2023; Société Générale, ADEME, Demeter)Tech.eu · https://tech.eu/2023/01/11/reclaiming-data-centre-waste-heat-nets-qarnot-eur35-million/11Turning heat into a resource — Mäntsälä supplies ~75% of town-centre district heat (~20,000-25,000 MWh/yr ≈ 2,500 homes)Nebius (sustainability) · https://nebius.com/sustainability/turning-heat-into-a-resource 12Stockholm — heat recovery from data centres (Open District Heating; 20+ suppliers, >100 GWh/yr, ~30,000 apartments)EU Covenant of Mayors · https://eu-mayors.ec.europa.eu/en/news/stockholm-sweden-heat-recovery-data-centres

A sample deliverable produced by Dossier, powered by the x1000 engine. Citations reflect sources as captured during research. This is a validation-stage assessment, not investment advice.