About the client

Industry
Production company
Location
Germany
Size
Family business with approx. 100 employees

Project profile

PV system
160 kW
Annual electricity generation
approx. 141,000 kWh
Annual surplus
approx. 77,500 kWh
Previous average feed-in tariff
approx. 3 ct/kWh
Challenge
low feed-in tariff
HASHLYNK system
HashRack Hydro with 9 miners, approx. 53 kW
Heat dissipation
external cooling circuit, integration into the heating system possible
Status
being implemented, commissioning planned for November 2026
Bitcoin strategy
holding (calculated over 4 years)

Why the business was looking for an alternative to feed-in

Of around 141,000 kWh of solar electricity per year, the business feeds around 77,500 kWh into the grid, for around 3 ct/kWh. More than half of its generation therefore earns hardly anything.

The aim was to use a larger share of this energy on site. Three practical questions had to be answered: where would the technology fit, how could noise be kept low, and where should the heat go?

Why the company chose HashRack Hydro

Following a site assessment, the company chose HashRack Hydro, the water-cooled version. It offers a higher energy density and keeps open the option of integrating the waste heat into the existing heating system later.

The design is a HashRack Hydro with nine Bitcoin miners and a total electrical power of around 53 kW. It will continuously adjust its consumption to the available PV surplus. The waste heat will initially be dissipated via an external cooling circuit. If the client later decides on a PV expansion, the system can easily be extended.

What to expect from the project

The HashRack Hydro is designed to put around 60,400 kWh per year to use on site. That is around 78 % of the previous feed-in. The modelled payback period is around 4.4 years, not yet including use of the waste heat.

BeforePlanned with HashRack Hydro
Utilisation

around 77,500 kWh per year fed in

around 60,400 kWh per year planned for use on site

Revenue

around 3 ct/kWh feed-in tariff

Bitcoin, holding strategy over four years

indicative value €0.10–0.20/kWh (4-year average)

Waste heat

–

initially dissipated via an external cooling circuit, integration into the heating possible

PV expansion

economically unattractive

system grows with it

This is equivalent to the HashRack Hydro running at full power for around 1,133 hours a year.

Good to know: All figures come from the base case of the project calculation with a four-year holding strategy. They are neither measured nor guaranteed, as the Bitcoin price, mining revenue and available energy can change the result. Later use of the heat is not included and would be an additional benefit. We will add initial measurements after commissioning.

“Companies often have ideal conditions: plenty of their own solar electricity, plenty of surplus and often a heat demand too. With falling feed-in tariffs, negative electricity prices and strict grid export limits, HASHLYNK systems are becoming increasingly attractive for them.”

Thomas EbnerCo-founder of HASHLYNK

Conclusion: more from its own solar electricity, with the option of using the heat

For the business, the priority was to use a larger share of its own solar electricity itself instead of feeding it in for around 3 ct/kWh. The Hydro version also keeps open the option of integrating the waste heat into the heating system later.

Three things speak for HashRack Hydro here: it can put a large part of the previous feed-in to use on site, later also supply heat from the same electricity and grow with a PV expansion.

Is this solution right for your system too?

A HASHLYNK system is particularly interesting if

  • your generation system regularly produces significantly more electricity than your business consumes,
  • the feed-in tariff is low or the grid limits feed-in,
  • you want to expand your system, but feeding in more does not pay off,
  • you could make good use of waste heat, for example for heating or process heat.

A site assessment shows whether this applies to your site.