Sealminer A4 Ultra Hydro
Bitcoin & Bitcoin Cash ASIC Miner
886TH
HASHRATE
9.45W/TH
EFFICIENCY
8373W
POWER
£884.77
EST. MONTHLY
NO PAYBACK
EST. ROI
Image: Irish Farmers Journal · Original source.
Renewables and heat reuse
Irish Farmers Journal visited Tom Campbell’s anaerobic-digestion site and its Scilling Digital Mining installation. The project uses stranded electricity beside a farm biogas plant.
- Project at a glance
- 500 kW AD plant reported
- Source date and context
- 21 December 2022
- 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
What the reporters found in Lurgan
The Irish Farmers Journal visited Tom Campbell's farm in December 2022. Its report describes a Scilling container sitting on top of the AD plant, with 35 ASICs installed and room for more. Campbell was looking for a use for additional generation that he could not readily export under the arrangements described in the report. This gives the story a concrete starting point: an existing farm generator finding another buyer for its electricity.
“the system can turn on and off as needed.”
Biogas gives the miners a regular supply
Farm biogas→engine electricity→on-site mining→Bitcoin revenue
Biogas generation can run outside daylight hours, although feedstock supply and engine maintenance still govern availability. The farm and the mining operation need separate budgets. A fixed electricity payment gives the farmer a different exposure from a share of the Bitcoin earned. The agreement also needs to say what happens when either the engine or the miners stop.
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
£15.901.59p per miner kWh
Here, using the electricity for mining gives up a 5p/kWh export payment. That cost includes the 50 kWh used by pumps and fans. It is the value of an alternative sale, so it is not also charged as a grid electricity bill. The example assumes the generation equipment already exists.
| Mining income | 8p per miner kWh; an assumed rate, not a live earnings estimate |
|---|---|
| Electricity | 5p/kWh × 1,050 kWh = £52.50 |
| Pool fee | 2% of gross mining income |
| Useful heat | 0% of miner electricity = 0 kWh; no heat income assumed |
| 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 | Operating contribution |
|---|---|
| 5p | −£13.50 |
| 8p Chart example | £15.90 |
| 11p | £45.30 |
- Mining income needed to cover running costs
- 6.38pper miner kWh
- Highest electricity cost or export value supported
- 6.51pper 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
If the electricity has no export value or other useful destination, removing the export cost improves this example by £52.50. Generator maintenance, equipment costs and any payment to the electricity owner still remain. Heat is given no value here because the source does not establish a usable heat supply.
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.
Agree who carries the operating costs
A farm can add a local electricity buyer where export capacity is constrained.
Record the electrical output that remains available, engine downtime, the connection agreement and maintenance responsibilities. Keep any existing CHP heat income separate.
Questions worth asking
- Who pays during engine outages?
- Would extra operating hours increase feedstock, service or engine-overhaul costs?
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: Irish Farmers Journal (source).
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