A 180-square-meter home in Nokia, Finland, has disconnected from district heating and now relies entirely on heat from Bitcoin mining equipment. The system, supplied by SunBit, illustrates both the appeal and the financial limits of using mining revenue to offset household heating costs.
The report, published on November 9, 2026, describes a business model in which mining income can cover electricity bills under specified assumptions. That does not make the equipment free: installation costs exceed $20,000, and returns depend on Bitcoin’s price, electricity tariffs and competition across the mining network.
How the Bitcoin boiler works
SunBit’s equipment converts nearly all the electricity consumed by a miner into heat, stores that heat in water at temperatures of up to 60°C, and distributes it through radiators or underfloor heating. The miner produces Bitcoin while supplying heat.
Founder and CEO Elmeri Suomi told CoinDesk that SunBit delivered its first production systems in 2025 and had 30 operating installations at the time of the report. All but one were in Finland. Its first overseas project, installed in Leekum in the Netherlands in 2025, replaced gas heating.
Other installations illustrate different configurations:
- A 200-square-meter home in Kotka combines mining equipment with an existing oil boiler.
- An old manor in Tampere replaced wood heating with a miner that maintains a 1,500-liter water tank at 50–60°C.
- A 3,000-square-meter industrial building in Vimpeli uses a similar system alongside an air-source heat pump and surplus electricity from a 30-kilowatt solar array.
Homeowners buy and own the equipment, pay for electricity and retain the Bitcoin produced, subject to applicable fees. Because miners are noisy, they are generally installed in basements or separate soundproofed rooms.
Suomi’s distinction is that market conditions change the payback period, not the equipment’s ability to produce heat.
The operating surplus depends on specific assumptions
SunBit’s model for the Nokia home uses a water-cooled Bitmain Antminer S21 XP Hydro with 495 TH/s of computing power and Braiins OS firmware. Running continuously at approximately 5.3 kilowatts, it consumes about 46,400 kilowatt-hours annually.
The company’s calculation assumes:
- Electricity at $0.11 per kWh, producing an annual bill of roughly $5,200.
- Bitcoin at $82,000.
- Total network computing power of 1,040 EH/s.
- Annual production of approximately one-twelfth of a Bitcoin.
Under those assumptions, annual Bitcoin proceeds would be worth about $6,100 after SunBit’s optional 10% service fee, with a further 0.5% mining-pool fee applicable. The reported operating surplus after electricity is roughly $900, before recovering the equipment cost.
Without the optional service, the modeled Bitcoin output would be worth approximately $6,800 before the pool fee. The service includes round-the-clock remote monitoring, optimization around Finnish variable electricity prices and a mobile app; grid-balancing functionality was planned as a later addition.
At the report’s Bitcoin price of approximately $81,500, SunBit put its operating break-even price near $70,000 after its service fee. That threshold excludes equipment costs and assumes unchanged network computing power. Additional mining competition would reduce an individual machine’s output.
Actual customer evidence was more limited. Suomi supplied a mining-pool screenshot from an early customer using a 358 TH/s S21+ Hydro. It showed 0.039 BTC mined over the preceding year, worth approximately $3,160 at the price cited. That installation could replace around 2,000 liters of heating oil annually. SunBit could access data from its early pilots, but later customers used private pool accounts that the company could not view.
Oil savings help, but heat pumps use less electricity
In a separate comparison, SunBit modeled a home consuming 2,300 liters of heating oil annually at approximately $2.19 per liter, or about $5,000 a year.
Replacing that oil consumption while generating a modeled $920 annual mining surplus after electricity produced an estimated payback period of roughly three and a half years on a $20,200 installation quote. That calculation excluded maintenance, financing costs and optional additions. An existing oil boiler could remain available for the coldest days.
However, the home cannot use all the heat produced. In the example discussed, more than half was surplus, discharged outdoors through an external dry cooler, particularly during summer.
Heat pumps present a different comparison. The report says they can deliver 2.5–3 units of heat per unit of electricity, compared with approximately one unit from a miner. For a home requiring 25,000 kWh of heat annually, SunBit estimated air-source heat-pump operating costs of about $1,100, versus $3,170 for district heating. Operating the miner only long enough to meet that heating requirement would, under its assumptions, generate approximately $490 after electricity costs.
The miner’s financial advantage therefore comes from Bitcoin revenue—not superior heating efficiency. Suomi argued that miners maintain their heat output in severe cold, whereas air-source heat-pump efficiency can fall sharply at −25°C. Unlike mining income, however, heat-pump economics do not depend on Bitcoin’s price.
The report gives an overall installed-price range of $20,400–$31,400 and estimated payback periods of three to six years.
Why the 2028 halving changes the calculation
The next Bitcoin halving, expected in spring 2028, would reduce the block subsidy from 3.125 BTC to 1.5625 BTC. Buyers installing systems during the winter discussed in the report could encounter that reduction before recovering their investment.
SunBit’s calculator did not incorporate the halving; it estimated payback using prevailing mining revenue. Suomi said the company did not predict Bitcoin prices or network computing power, did not promise fixed returns, and explained previous halvings to customers.
Holding the other modeled conditions unchanged, the report estimates that mining revenue would fall from about $0.13 to $0.07 per kWh after the halving—below the assumed $0.11 electricity price. Net heating costs would then be approximately $0.04 per kWh of heat, described as close to the operating cost of a comparable air-source heat pump.
Under that same formula, Bitcoin would need to reach approximately $131,000 for mining revenue to continue covering electricity after the halving. That is a conditional break-even estimate, not a price forecast. Changes in electricity prices or network competition would alter the result.
The central distinction is between dependable heat production and uncertain mining income. SunBit’s systems can keep producing heat regardless of Bitcoin’s price; whether that heat is effectively free—and whether the installation pays for itself—remains contingent on mining economics.
Source: Original article on PANews, published November 9, 2026, at 21:49 UTC+8. The supplied article credits reporting to Shaurya Malwa of CoinDesk and translation to Chopper of Foresight News. Prices, installation counts and payback estimates reflect that reporting period.
