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: Terahash / Kläger Group · Original source.
Renewables and heat reuse
Terahash describes Kläger Group’s Hartha energy park with a 1.6 MWp solar array, a 350 kWh battery and a mining container able to absorb up to 500 kW. The container is intended to buy surplus left by industrial production, with storage and grid export also available.
- Project at a glance
- 1.6 MWp solar · 350 kWh battery · up to 500 kW mining
- Source date and context
- Operator page reviewed 29 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
Four possible uses for the next unit of solar power
Terahash describes a 1.6 MWp solar array, a 350 kWh battery and a mining container able to take up to 500 kW at Kläger Group's Hartha site. Industrial production comes first. Mining provides another destination for surplus electricity, with storage and grid export also available. The account does not document heat recovery at this installation.
“An installed mining container serves as buyer of last resort for excess electricity.”
Production, mining, storage and export
PV→production, controllable mining, battery and grid export
The battery stores energy; the miner rating describes how quickly energy is used. At a constant 500 kW, 350 kWh would last 42 minutes in a simple calculation before losses, reserves or discharge limits. That is a useful sense check, rather than the site's stated operating schedule. The best use of a surplus kWh depends on export prices, mining income and the cost of storing it.
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.
Compare each option at the same time
Compare mining, storage and export using the value of the same surplus electricity at the same time.
Obtain interval dispatch data, battery efficiency and degradation costs, miner revenue and export settlements. Compare the complete operating schedule rather than headline component ratings.
Questions worth asking
- When should the battery take priority over mining?
- Does a fixed dispatch order still make sense under changing electricity prices?
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: Terahash / Kläger Group (source).
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