{ "meta": { "title": "D-Central — Bitcoin Heat-Reuse Deployment Registry", "description": "A verifiable registry of 12 real-world Bitcoin (and closest-compute) heat-reuse deployments — district heating, spas/pools, greenhouses, drying, aquaculture and residential heaters — with scale, economics and a measured/reported/PR-only confidence flag per row.", "generated": "2026-07-18T06:47:21+00:00", "version": "1.0", "license": "https://creativecommons.org/licenses/by/4.0/", "license_name": "CC BY 4.0", "source": "https://d-central.tech/bitcoin-heat-reuse-registry/", "method": "Confidence flag is the point: \"measured\" = independent/published numbers; \"reported\" = operator numbers, plausible and often cross-reported; \"PR-only\" = marketing claim with no numbers. Nothing here reached fully-independent \"measured\" — the strongest tiers are Bathhouse NYC (cross-reported across Fortune/TIME/MIT) and Heata (Centrica-confirmed trial). Deployments flagged bitcoin=false (Qarnot, Heata) are HPC/cloud-compute analogs, not bitcoin, and labeled as such. Two headline corrections: \"whole city / 80,000 residents\" figures are the district network TOTAL population, not the bitcoin-heat fraction; mining preheats water that heat pumps finish.", "provenance": "Company sites and case studies plus reputable third-party reporting (DataCenterDynamics, Fortune, TIME, MIT Technology Review, CryptoSlate, Centrica, Hashrate Index). D-Central's own product row is self-reported spec, kept neutral.", "disclaimer": "Bitcoin heat is abundant LOW-GRADE heat: air-cooled ASICs exhaust ~35-45°C air; immersion/hydro delivers ~60-75°C water. It substitutes for a furnace/electric heater, not for industrial process or steam heat. Consumer-heater economics live or die on the local electricity price; at high rates the BTC earned is negligible. Not financial advice." }, "rows": [ { "name": "Bathhouse (Brooklyn + Manhattan)", "operator": "Bathhouse (spa, self-mines)", "location": "New York, USA", "canada": false, "category": "water-heating", "scale": "~12 ASICs Brooklyn, ~20 Manhattan; Flatiron 14 miners (~2,600 TH/s) heat 4 pools + 3 hammams", "what": "Off-the-shelf ASICs have fans removed, are immersed in dielectric fluid, and a heat exchanger pipes the heat into pools (~105°F/40.5°C) and heated marble; miners idle once pools hit target.", "heat_output": "Pools held ~40.5°C — a textbook match for immersion-ASIC low-grade heat", "economics": "Brooklyn power ~$20k/mo, Manhattan ~$40k/mo (roughly unchanged); mining earned ~1.5 BTC in a year (~$90k reported) — heat that would otherwise cost gas/electric is offset while earning BTC", "status": "operational", "confidence": "reported", "year": "2023-2025", "bitcoin": true, "source": "Fortune / TIME / MIT Tech Review / DCD", "notes": "The best-documented commercial case — $ and BTC figures are operator-stated but consistent across multiple outlets. Strongest 'real economics' example here." }, { "name": "MintGreen × Lonsdale Energy Corp", "operator": "MintGreen + Lonsdale Energy Corp (city utility)", "location": "North Vancouver, BC, Canada", "canada": true, "category": "district-heating", "scale": "Deal targets ~100 buildings on LEC's loop (LEC's TOTAL network ~6,500 homes — bitcoin supplies a slice, not the whole grid)", "what": "Immersion 'Digital Boiler' ASIC systems feed recovered heat into LEC's existing hot-water district loop. Announced 2021 as 'world's first city heated by bitcoin'.", "heat_output": ">96% of mining electricity recovered as heat (operator claim); district loop is low-temp hot water, heat-pump boosted", "economics": "GHG claim ~20,000 t CO2 reduced per MW vs natural gas (operator, not audited); no $ figures", "status": "operational", "confidence": "reported", "year": "2021-2026", "bitcoin": true, "source": "Daily Hive / District Energy / mintgreen.co", "notes": "🔴 HONESTY: the '6,500 homes' headline is LEC's ENTIRE network capacity, NOT the bitcoin-heat fraction (~100 buildings). No third-party metered delivery numbers. Canada's flagship example." }, { "name": "MintGreen × Shelter Point Distillery", "operator": "MintGreen", "location": "Vancouver Island, BC, Canada", "canada": true, "category": "industrial", "scale": "8× Antminer S9 in a rotating immersion 'tumbler'", "what": "Eight immersion-cooled S9s heat the whisky barrel-storage room and assist the mash process. MintGreen's first commercial heat-offtake project.", "heat_output": "Low-grade room/process heat (S9 immersion); no published temperature/kW", "economics": "unverified", "status": "operational", "confidence": "reported", "year": "2020-2026", "bitcoin": true, "source": "mintgreen.co", "notes": "A genuine small real distillery deployment (the 'whisky' case). Operator-described only; no measured energy data." }, { "name": "MARA Holdings district heating", "operator": "MARA Holdings (ex-Marathon Digital)", "location": "Satakunta, Finland", "canada": false, "category": "district-heating", "scale": "Phase 1 ~11,000 residents; scaled to a claimed ~80,000 across two districts", "what": "Mining exhaust air passes a heat exchanger warming water to 25-35°C, which district heat pumps boost to 80°C for the municipal grid. Launched June 2024.", "heat_output": "Air→water at 25-35°C, upgraded to 80°C by heat pumps — mining alone does NOT reach district temp", "economics": "'Avoided emissions equivalent to ~700 US homes' since 2024 (operator figure); no $ published", "status": "operational", "confidence": "reported", "year": "2024-2026", "bitcoin": true, "source": "DataCenterDynamics / CryptoSlate / Grist", "notes": "🔴 HONESTY: '80,000 residents' is the district network's served population, NOT a metered mining-heat fraction — mining PREHEATS, heat pumps finish. Widely reported but figures originate with MARA." }, { "name": "KryptoVault timber (and seaweed) drying", "operator": "KryptoVault", "location": "Hønefoss, Norway", "canada": false, "category": "drying", "scale": "45 MW facility; heat piped to 12 timber-drying container skips", "what": "Hydropowered mining exhaust is channeled via corrugated pipes into twelve 'skips' to dry damp timber in ~4 hours vs 2-3 months of sun-drying. Seaweed drying floated as next step.", "heat_output": "Warm exhaust air (air-cooled); enough to rapid-dry lumber", "economics": "unverified (dramatic time-savings claim, no $)", "status": "operational", "confidence": "reported", "year": "2019-2023", "bitcoin": true, "source": "Bitcoinist", "notes": "A real, oft-cited industrial drying example. The '4 hours vs 2-3 months' is the operator's — plausible for forced-hot-air kiln drying, not independently measured." }, { "name": "HeatCore + MicroBT heat recovery", "operator": "HeatCore + MicroBT", "location": "China + Bellefonte, PA, USA (pilot)", "canada": false, "category": "industrial", "scale": ">300 MW deployed globally by end-2024; HS05 household unit = 5 kW (WhatsMiner M64)", "what": "Has heated a commercial office and maintained constant-temperature fish-farming pools in China; a US pilot demonstrated fish hatchery, hydroponics and space heating from hydro-cooled miners. Seawater-desalination heating announced for 2025.", "heat_output": "Hydro-cooling (water-cooled) enables higher-grade heat than air; HS05 ~5 kW", "economics": "unverified", "status": "operational", "confidence": "reported", "year": "2022-2025", "bitcoin": true, "source": "Newswire (MicroBT/HeatCore)", "notes": "'>300 MW' is total capacity, not verified heat-delivered. Multiple named use-cases but no independent performance numbers; desalination is announced, not proven." }, { "name": "Genesis Digital Assets greenhouse pilot", "operator": "Genesis Digital Assets + RISE / Luleå University", "location": "Boden, Sweden", "canada": false, "category": "greenhouse", "scale": "One 600 kW air-cooled container feeding a 300 m² greenhouse", "what": "A 600 kW mining container's exhaust heat is ducted to a 300 m² greenhouse growing fruit/vegetables; research partners studied fish, insect, algae and fruit-drying extensions. Announced Dec 2020 as an R&D pilot.", "heat_output": "Air-cooled exhaust (warm air, not hot water); 600 kW thermal source", "economics": "unverified", "status": "pilot", "confidence": "PR-only", "year": "2020-2021", "bitcoin": true, "source": "news.bitcoin.com", "notes": "Heavily press-released in 2020-21 with little follow-up on yields or continuation. Treat as a research pilot of uncertain current status — no harvest/economic numbers ever published." }, { "name": "Heata networked server water heaters", "operator": "Heata (spun from British Gas/Centrica)", "location": "United Kingdom", "canada": false, "category": "water-heating", "scale": "Trial: 10 units in British Gas employee homes; broader home rollout", "what": "A compute server is bolted directly to a home hot-water cylinder; processing heat transfers into the tank for free hot water. Founding prototype was a literal bitcoin-miner-in-oil, since pivoted to general cloud compute.", "heat_output": "Up to ~4.8 kWh/day into the cylinder (≥2.5 kWh contractual); domestic hot-water temps", "economics": "Modeled savings up to £340/yr (offsetting electric hot water) or ~£120/yr (offsetting gas); free hot water to host", "status": "pilot", "confidence": "reported", "year": "2023-2025", "bitcoin": false, "source": "Tom's Hardware / Centrica", "notes": "NOW general compute, NOT bitcoin — included because the founding prototype was a bitcoin miner and it's the clearest residential hot-water £-savings data point. Savings are modeled, backed by a real Centrica-confirmed trial." }, { "name": "Qarnot 'Digital Boiler' / QBx", "operator": "Qarnot Computing", "location": "France / Finland / Brescia, Italy", "canada": false, "category": "water-heating", "scale": "~30 sites across Europe; Brescia phase 1 = 30 QBx units, ~800 MWh thermal/year", "what": "Compute modules are cooled by water that exits at ~65°C and feeds building/district hot water. Brescia (with utility A2A) is the flagship district tie-in.", "heat_output": "Water out at ~65°C; ~95% of compute energy recovered; Brescia ~800 MWh/yr thermal", "economics": "unverified (ADEME/ENGIE-backed social-housing pilots; no public $)", "status": "operational", "confidence": "reported", "year": "2010s-2025", "bitcoin": false, "source": "DataCenterDynamics", "notes": "HPC/cloud compute, NOT bitcoin — included as the closest proven compute-heat-reuse analog and because its 65°C water shows what liquid cooling unlocks vs air. Its ~800 MWh/yr is one of the few hard thermal numbers in this space." }, { "name": "Heatbit Trio / Maxi", "operator": "Heatbit (consumer product)", "location": "Consumer product (incl. Canada)", "canada": true, "category": "residential", "scale": "~1,500 W/unit; Maxi up to ~39 TH/s, Trio ~10-14 TH/s (only ~400 W drives the chip)", "what": "A designer plug-in space heater with an embedded ASIC; nearly all electricity becomes room heat while a fraction of value returns as BTC. Maxi retails ~US$1,249.", "heat_output": "~1,500 W room heat (~35-45°C exhaust air); heats one room, not a house", "economics": "Reviews: mining offsets only a small share of running cost; net economics hinge entirely on local electricity price; Trio BTC earnings described as 'negligible'", "status": "operational", "confidence": "reported", "year": "2022-2026", "bitcoin": true, "source": "Bob Vila / independent reviews", "notes": "Independent reviews exist (hence 'reported'). Honest framing: a premium electric heater with a small BTC rebate, not an investment." }, { "name": "Canaan Avalon Mini 3 / Avalon Q", "operator": "Canaan (manufacturer)", "location": "Consumer product (incl. Canada)", "canada": true, "category": "residential", "scale": "Mini 3: 37.5 TH/s, 800 W, ~21.3 J/TH; Avalon Q ~90 TH/s", "what": "A quiet (33-55 dB) home ASIC that doubles as an 800 W space heater — all 800 W becomes ~2,730 BTU/hr. Ships assembled, plug-and-play, with tip-over protection and thermostat cycling.", "heat_output": "~2,730 BTU/hr (~800 W); ~80 sq ft primary heat; raises a 10 m³ room 15→21°C in ~10 min", "economics": "unverified (no independent net-cost study; economics = electricity price minus BTC earned)", "status": "operational", "confidence": "reported", "year": "2024-2026", "bitcoin": true, "source": "Hashrate Index", "notes": "Real shipping product with published specs. Heating figures are manufacturer specs; mining-vs-electricity economics are the buyer's to compute — no neutral third-party ROI data found." }, { "name": "D-Central Bitcoin space heaters", "operator": "D-Central Technologies", "location": "Laval, Quebec, Canada", "canada": true, "category": "residential", "scale": "From $235 CAD; S19 edition ~95 TH/s (or ~50-70 undervolted) ≈ up to ~11,090 BTU/hr; BitChimney = single-hashboard S19 convection", "what": "Refurbished ASICs (S9, S17, S19, L3+) professionally converted into noise-dampened residential heaters in D-Central's Quebec workshop. The BitChimney is a 3D-printed vertical convection enclosure for silent operation.", "heat_output": "S19 edition up to ~11,090 BTU/hr; air-cooled (~35-45°C exhaust); single-room heat", "economics": "unverified (product spec; net cost depends on local power + BTC price)", "status": "operational", "confidence": "reported", "year": "2016-2026", "bitcoin": true, "source": "d-central.tech (self-reported)", "notes": "The registry owner's OWN product line — kept scrupulously neutral. Specs are D-Central's own (self-reported, so not 'measured'). Same honest caveat as every consumer heater: an electric heater with a BTC rebate whose economics hinge on local rates." } ] }