Sealminer A4 Ultra Hydro
Bitcoin & Bitcoin Cash ASIC Miner
886TH
HASHRATE
9.45W/TH
EFFICIENCY
8373W
POWER
£862.14
EST. MONTHLY
NO PAYBACK
EST. ROI
Image: Hashlabs · Original source.
Renewables and heat reuse
Hashlabs describes capturing heat from its Finland mining project and supplying it to a local district heating network.
- Project at a glance
- District-heating connection
- Source date and context
- Undated operator page; reviewed September 2026
- Published financial detail
- The sources reviewed do not include full project accounts.
- Our comparison
- A UK example per 1,000 miner kWh
About 5 minutes to read
A hosting site with a local heat customer
Hashlabs says heat from its Finland mining project is captured and supplied to a local district heating network. The arrangement brings two customers into the same installation: owners who pay for their miners to be hosted, and a network that needs heat. Each receives a different service. The financial benefit depends on how the hosting and heat supply agreements divide the income and costs.
“At our Finland project, heat generated by the mining machines is captured and supplied to the local district heating network.”
One installation serves two customers
Mining electricity→captured heat→local district network
A competitive hosting tariff does not reveal the economics of the heating connection. Heat income might stay with the facility, support a lower hosting price or cover part of the site's operating costs. Before comparing the model with a UK installation, ask for the heat delivery profile, temperatures, connection costs and contract terms.
What the numbers could look like in the UK
The calculation below uses assumed UK prices to show how the costs fit together. It is our example, not this project’s reported earnings. Replace the inputs with current machine estimates and the costs at your own site.
Illustrative UK calculation
Income and running costs
1,000 kWh used by miners, plus 50 kWh for pumps and fans. All amounts in pounds.
Operating contributionBefore equipment and installation costs
−£9.60−0.96p per miner kWh
This example buys electricity at 12p/kWh and values useful heat at 6p/kWh. These are assumed prices. The heat value should be replaced with the actual cost of the heating you would otherwise use, or the price a customer agrees to pay.
| Mining income | 8p per miner kWh; an assumed rate, not a live earnings estimate |
|---|---|
| Electricity | 12p/kWh × 1,050 kWh = £126.00 |
| Pool fee | 2% of gross mining income |
| Useful heat | 80% of miner electricity = 800 kWh; valued at 6p per delivered kWh |
| Other running costs | £10 per 1,000 miner kWh; an allowance to replace with your own costs |
| Costs still to add | Equipment, installation, finance, tax, depreciation, major replacements and any costs above the allowance |
The contribution is what remains from mining income and useful heat after the stated running costs. It is not net profit: the equipment and other excluded costs still have to be recovered. Pumps and fans use electricity but earn no mining income in this calculation.
| Gross income per miner kWh | Without heat value | With useful heat |
|---|---|---|
| 5p | −£87.00 | −£39.00 |
| 8p Chart example | −£57.60 | −£9.60 |
| 11p | −£28.20 | £19.80 |
- Mining income needed to cover running costs
- 8.98pper miner kWh
- Highest electricity cost or export value supported
- 11.09pper total electricity kWh
These are two ways to read the same example. Adding equipment costs or a larger maintenance allowance raises the income needed and reduces the electricity price the project can afford.
Compare heating options and work out annual costs
Use the heating system you would actually choose as the comparison. For example, a heat pump using electricity at 20p/kWh with a seasonal COP of 3 has an electricity cost of about 6.67p per kWh of heat. A resistance heater at that tariff uses 20p per kWh of heat. These are calculation examples, rather than measurements from this project.
For an annual estimate, use the miner electricity expected during hours when running makes sense. Scale the contribution by annual miner kWh divided by 1,000, then deduct fixed annual costs. Recalculate if electricity prices, mining income or usable heat change.
Simple payback is the total installed cost divided by positive annual cash contribution. There is no payback under a scenario with zero or negative contribution. The sources reviewed here do not provide the full project accounts needed to calculate an actual payback for this installation.
Find out who receives the heat income
A contracted heat buyer can turn an unwanted cooling load into a useful local service.
Request the heat-sale agreement, delivered temperature range, annual acceptance profile and measurement boundary. Distinguish hosting customer returns from the facility owner’s returns.
Questions worth asking
- Can heat revenue change the hosting tariff?
- What happens to heating supply if the miner owner switches equipment off?
Try your own electricity and heat figures
Compare available miners and dated earnings estimates. Include heat only where you can use it or have a customer for it.
Sources and photographs
Sources checked on 29 September 2026. Project facts and quotations come from the publications below; the UK calculations and practical assessment are The Mining Shop’s analysis. This article is based on published material, rather than a site visit.
Photographs: Hashlabs (source).
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