About Altholz Bodner
- Company
- Altholz Bodner
- Industry
- Craft and trading business
- Location
- Sachsenburg, Upper Carinthia, Austria
Project profile
- PV system
- 75 kW
- Annual electricity generation
- approx. 60,000 kWh
- Annual surplus
- approx. 50,000 kWh
- Feed-in tariff 2025
- approx. 1.5 ct/kWh (effective)
- Challenge
- grid export limit, low feed-in tariff
- HASHLYNK system
- HashRack in a container, up to 25 kW total output
- Status
- in operation since March 2026
- Bitcoin strategy
- holding on a hardware wallet
Why feeding in no longer paid off for Altholz Bodner
Of the around 60,000 kWh of solar electricity generated per year, the business itself needs only a small part. The rest had to go into the grid, which could not take all of it because of the grid export limit. And what was fed in earned hardly anything.
This made the value of the PV system depend on two factors that Altholz Bodner cannot influence: grid capacity and the level of the feed-in tariff. Altholz Bodner therefore wanted to put the surplus to use directly on site, independently of the grid and the feed-in tariff and without additional effort in day-to-day operation.
A HashRack that follows the surplus
It all started with a site assessment by HASHLYNK: how often and for how long does surplus actually occur at the site? On this basis, a HashRack was designed that continuously adjusts its power to the available solar electricity.
The design was based on the load profile, the surplus profile and the business's operating processes, because installed PV capacity alone says little about how much electricity can actually be put to use. For Altholz Bodner, the design comes to around 38,000 kWh per year, or around 76 % of the surplus. This is equivalent to the system running at full power for around 1,800 hours a year.
In the knowledge hub, we explain the basic options for using surplus electricity and how the electricity turns into revenue.
Why not 100 % of the surplus?
A larger system would have been technically possible. However, the last few percent of surplus occur in only a few hours a year. Additional equipment for them would hardly be utilised and would pay for itself more slowly. That is why the system is designed for a fast payback within the budget. The remaining 24 % or so continues to be fed in as far as possible and stays in reserve for a later expansion.
What has changed for Altholz Bodner
Instead of feeding in only part of the surplus because of the grid export limit, at around 1.5 ct/kWh, the HashRack is designed to put around 76 % of it to use on site. A payback period of around 3 years is expected for the overall system.
| Before | With HashRack | |
|---|---|---|
| Utilisation of the surplus | feed-in only, restricted by the grid export limit | around 38,000 kWh per year planned for use on site |
| Revenue from the surplus | around 1.5 ct/kWh feed-in tariff | around 0.059 BTC per year on average (modelled, over 4 years) |
| PV expansion | not economically viable | economically viable again |
In the media: The Kleine Zeitung also reported on the project: “Überschussstrom wird hier zu Bitcoin verwertet” (15 April 2026).
Good to know: Since commissioning in March 2026, the surplus has earned around 5 times as much every month as in the same month of the previous year with feed-in (as of October 2026). We will add a full annual balance after the first year of operation.
“We had a lot of electricity that would otherwise have gone into the grid. Now we can put it to economic use.”
A holding strategy instead of an immediate sale
Altholz Bodner collects the Bitcoin it earns on a hardware wallet and does not sell it straight away. This means the timing of the sale also influences how economical the project ultimately is.
So monetisation does not end with mining but continues in the sales strategy. For the economics, it is therefore not only the number of kWh put to use that counts. What matters is the entire path from surplus electricity through computing power to the value realised.
Outlook: using the waste heat for timber drying
Plans are already under consideration at the site to use the HashRack's waste heat for timber drying in future. The surplus electricity would then deliver a double benefit: revenue from computing power and heat for drying the timber.
For businesses with suitable processes, this is a decisive point. It is then no longer just about putting PV surplus to better use, but about turning electricity and heat together into an advantage for the site.
Is this solution right for your business 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 drying or heating.
A site assessment shows whether this applies to your site.
See the system in practice: If you would like to see a project like this on site, you can visit the Altholz Bodner site by arrangement. A real system in day-to-day operation often says more than technical data and economic models.
Conclusion: surplus electricity needs a better route to value
The Altholz Bodner reference project shows that what matters is not only how much electricity a PV system produces, but how much of it can be put to good use under real conditions.
At Altholz Bodner, four things were decisive: a high annual surplus, limited feed-in options, a design optimised for a fast payback and the option of developing the site further later on. Surplus electricity is thus no longer just a quantity fed into the grid, but a path to value that can be shaped.
