SunBit’s Bitcoin-mining calculator models whether mining revenue can cover electricity costs while a household uses the machines’ heat. It is a cash-flow estimate—not a Bitcoin valuation model or a price forecast. Its central limitation is that it estimates payback from prevailing mining economics without incorporating the next halving.
That distinction matters when an installation costing more than $20,000 has an estimated payback period of three to six years.
This historical account draws on a report credited to Shaurya Malwa of CoinDesk, translated by Chopper of Foresight News, and published by TechFlow on November 9, 2026, at 18:07:09 UTC+8. Prices and operating estimates below belong to that reporting context, not to live market conditions.
What goes into the calculation
The example supplied by SunBit uses a Bitmain Antminer S21 XP Hydro running Braiins OS, with these assumptions:
- Hash rate: 495 TH/s.
- Power consumption: approximately 5.3 kW, operating continuously.
- Annual electricity use: approximately 46,400 kWh.
- Electricity price: $0.11 per kWh, for a reported annual bill of about $5,200.
- Bitcoin price: $82,000.
- Network hash rate: 1,040 EH/s.
Under those assumptions, SunBit estimated annual production of approximately one-twelfth of a bitcoin. After its optional 10% service fee, the report put the proceeds at about $6,100, with a further 0.5% mining-pool fee applicable. Without the optional service, estimated proceeds were about $6,800 before the pool fee.
The resulting operating surplus was approximately $900 a year with the service. Calling the associated heat “free,” however, describes an operating-cost outcome under those assumptions. It does not mean the equipment has paid for itself.
Operating break-even is not investment payback
The report placed SunBit’s operating break-even Bitcoin price at approximately $70,000, after the service fee. That figure excluded equipment purchase costs and assumed an unchanged network hash rate. More competing mining capacity would reduce the individual machine’s expected production.
A separate company comparison estimated a roughly three-and-a-half-year payback for a $20,200 installation, excluding extras, maintenance and financing interest. That calculation combined avoided heating-oil expenditure of about $5,000 annually with approximately $920 in annual mining surplus after electricity.
The distinction is important: most of that modeled benefit came from replacing an existing heating expense, not from mining profit alone. It was therefore a household-specific comparison, not a general estimate of Bitcoin’s value.
Heat utilization also limits the calculation. The report said more than half the machine’s heat could go unused in the residential example, with excess heat discharged outdoors. Mining converts roughly one unit of electricity into one unit of heat; the report’s heat-pump comparison used 2.5–3 units of heat per unit of electricity. The miner’s financial advantage depended on mining proceeds, not superior heating efficiency.
The omitted change: the 2028 halving
The next halving was expected in spring 2028, reducing the block subsidy from 3.125 BTC to 1.5625 BTC. SunBit’s calculator did not incorporate that reduction into its payback estimates.
Holding the other modeled conditions unchanged, the report estimated that mining proceeds would fall from approximately $0.13 to $0.07 per kWh of electricity consumed—below the assumed $0.11 electricity price.
Under the same calculation, maintaining “free heating” after the halving would require a Bitcoin price of roughly $131,000. That is a conditional threshold, not a forecast: it depends on the calculation’s other assumptions holding.
SunBit CEO Elmeri Suomi said he would not predict Bitcoin prices or network hash rate, and the company did not promise fixed returns. The model is best read accordingly: as a scenario showing how selected inputs affect operating economics, not evidence that future revenue will repay an installation on schedule.