⛏️ Hydro Miner Heat Reuse Calculator
What's your electricity actually costing you after you factor in the heat?
BackgroundI've been running hydro miners for home heating for a while. Every time I explain the economics to someone, I end up doing the same math on a napkin:
"Your real electricity cost isn't €0.22/kWh — it's more like €0.10 once you account for the heating you're not paying for."Nobody had built a proper calculator for this, so I built one.
mineshop.eu/heat-reuse-calculator
What it calculatesMost "mining profitability" tools treat electricity as a pure cost. They ignore that a hydro miner converts 98% of its power draw into usable heat — heat that would otherwise come from your boiler, heat pump, or pellet stove.
The calculator models the full picture:
- Outdoor temperature slider (−25°C to +15°C) — your savings swing dramatically between a mild October and a −15°C January
- Heat pump COP degradation — rated COP is measured at +7°C. At −20°C it drops to ~1.5. Most calculators use a fixed COP. This one doesn't.
- Heating degree-day model — actual monthly heat demand based on your house size (m²) and energy class (A+ through G)
- Heating type comparison — gas, heat pump, pellets, or oil. Each has different economics.
- Live BTC/LTC/DOGE prices — fetched from CoinGecko at page load
- EUR/USD toggle — all outputs convert live
- Effective kWh rate — the number that actually matters
The core formula (transparent)Monthly heat demand = m² × (class_factor ÷ 4500) × max(0, 20 − outdoor_temp) × 30
Heat pump COP(temp) = rated_COP − (7 − temp) × (rated_COP − 1.2) ÷ 32 [min 1.2]
Heating saved (€) = min(miner_heat, heat_demand) ÷ COP × electricity_price
Effective rate (€/kWh) = (gross_cost − heating_saved) ÷ monthly_kWh_consumed
Energy class factors (kWh/m²/year):
A+ = 54, A = 100, B = 155, C = 220, D = 300, E = 380Calibration anchor: 450 m² A+ house at −20°C = ~6,500 kWh/month. Matches real Baltic heat pump data.
Example: Antminer S23 Hydro at −10°C- Power draw: 5,360 W
- Gross electricity cost: €849/month at €0.22/kWh
- Heat produced: 5,253 W → 3,782 kWh/month
- COP at −10°C: ~2.0
- Heat pump would have used: 3,782 ÷ 2.0 = 1,891 kWh → worth €416
- Net mining cost: €849 − €416 = €433/month
- Effective electricity rate: €0.112/kWh — nearly half the grid rate
And you're mining Bitcoin the entire time.
Supported miners (preloaded)SHA-256 hydro: Antminer S19/S21/S23/S21 XP Hydro, Whatsminer M56S++, M66S Hydro
Scrypt hydro: Antminer L11 Hydro, Volcminer D1 Hydro
Custom: enter your own wattage and hashrate
Full i18nAvailable in English, Dutch, German, French, Spanish, Swedish.
German and Dutch are our biggest markets — a lot of European home miners running hydro setups.
Open to feedbackEspecially from people who are actually running hydro miners for heating:
- Does the COP curve match your real-world numbers at low temperatures?
- Are there heating system types I'm missing (district heating, wood boilers)?
- Does the degree-day model hold up outside of Baltic/Northern Europe climates?
The methodology is explained on the page itself — nothing black-box.
Try it: mineshop.eu/heat-reuse-calculator— Guntis, Mineshop.eu
