SunBit heats Finnish buildings with bitcoin miners

Finnish startup SunBit has 30 "Bitcoin Boiler" systems running — heat-reuse rigs that capture the warmth of bitcoin mining computers and push it through radiators and underfloor pipes like a conventional boiler while earning BTC. At today's prices each unit earns slightly more than the electricity it burns, so a homeowner gets heat with no ongoing net energy bill, CEO Elmeri Suomi says.

• Systems cost $20,000 or more to install; profitability depends on bitcoin's price, electricity costs and mining competition.
• All but one of the 30 units are in Finland, replacing gas, oil, wood and district heating; the first export, a 2025 project in Lekkum, the Netherlands, replaced gas heating.
• The expected spring 2028 halving cuts new-coin mining rewards in half — likely before homeowners recoup their investment, a factor SunBit says is not part of its payback calculations.
• Miner MARA separately feeds waste heat into Finnish district heating networks, warming about 80,000 residents.