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: MARA · Original source.
Renewables and heat reuse
MARA describes 1 MW of mining heat at 50–60°C, supplemented by heat pumps for a network whose peak winter requirement reaches 95°C.
- Project at a glance
- 1 MW miner heat reported
- Source date and context
- 30 July 2025
- 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
Why this network also needs heat pumps
At Seinäjoki, MARA reports 1 MW of recovered miner heat at 50°C to 60°C. The district network can need water at 95°C in peak winter conditions, so heat pumps are part of the installation. The heating operator's account describes replacing peat, oil and wood. This is useful evidence of a real heat customer, while the complete project cash flow remains outside the published account.
“With that heat, we replaced peat, oil, and wood.”
Account for the temperature lift
Miner heat→heat pump and heat exchanger→district heating
A heat pump raises the delivery temperature by using additional electricity. Its output includes both recovered source heat and the compressor's contribution. A UK assessment should therefore meter the miners, compressors and circulation pumps separately. The heat pump's performance at the required winter temperature will matter more than a general efficiency figure from a brochure.
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
−£15.60−1.56p 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 | 70% of miner electricity = 700 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 | −£45.00 |
| 8p Chart example | −£57.60 | −£15.60 |
| 11p | −£28.20 | £13.80 |
- Mining income needed to cover running costs
- 9.59pper miner kWh
- Highest electricity cost or export value supported
- 10.51pper 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 a system like Seinäjoki, add the heat pump as a separate part of the calculation: compressor electricity, additional heat output, circulation and installed cost. The chart above covers recovered miner heat only.
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.
Include the compressor in the electricity bill
Include booster electricity and backup plant in the economics of higher-temperature heating.
Measure miner electricity, compressor electricity, pump loads and useful network heat independently. Use the heat pump’s measured performance at actual design temperatures.
Questions worth asking
- Who owns the heat pump?
- Does the agreed heat price cover its electricity, service and replacement cost?
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: MARA (source).
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