Armstrong International Launches Geothermal Industrial Heat Pump Production Site in Herstal, Belgium

How Geothermal Power Is Rewiring Industrial Heat in Herstal

By:Robert Buluma

In Herstal, Belgium, a quiet but consequential shift is taking shape. Armstrong International, a company long known for thermal utility solutions, is building a new production site for high-temperature industrial heat pumps that will itself be powered by an innovative closed-loop geothermal system. Named CircularSteam1, the project combines manufacturing, geothermal energy, and circular thermal thinking on a former mining site. When it opens in 2027, the plant aims to produce roughly 100 industrial heat pumps per year, each delivering up to 1 MW and able to raise temperatures to 120°C — high enough to serve many industrial processes previously dependent on fossil-fuel boilers.

Why geothermal matters for industrial heat

Geothermal energy is often associated with large-scale electricity generation or the warm springs that draw tourists. But its quiet power as a stable, local supply of low-grade heat makes it a particularly attractive partner for industrial decarbonization. Unlike intermittent renewables, shallow closed-loop geothermal systems provide steady heating in winter and cooling in summer, and they do so with minimal surface footprint and predictable operating costs.

In the context of CircularSteam1, geothermal serves two complementary roles:

- It decarbonizes the factory’s own heating and cooling needs, replacing what would otherwise be a gas boiler.

- It demonstrates an integrated approach where a manufacturer of industrial heat pumps both uses and showcases low-carbon thermal technology.

Closed-loop geothermal: reliability, longevity, low risk

The system installed at CircularSteam1 uses 30 geothermal probes drilled to about 140 meters in a closed-loop configuration. A heat-transfer fluid circulates through buried pipes to absorb or dissipate heat to the surrounding ground. Closed-loop geothermal systems are particularly well-suited for industrial sites because they:

- Avoid direct groundwater extraction, reducing contamination and permitting risks.

- Offer symmetrical heating and cooling performance, valuable for factories with seasonal thermal swings.

- Can be designed to operate for decades with modest maintenance if thermal balance is managed correctly.

A smart detail of the Herstal design is that heat rejected during testing of the newly manufactured industrial heat pumps will be recovered and reinjected into the ground. That reinjection maintains the subsurface thermal resource and prevents progressive cooling of the geothermal field — essentially feeding the ground with the byproduct heat so the system can keep delivering for decades.

Industrial heat pumps: unlocking higher-temperature industrial processes

Heat pumps work by moving heat from a lower-temperature source to a higher-temperature sink, using electricity to power a compressor and associated components. Historically, heat pumps excelled at supplying space heating and low-temperature process heat. Armstrong’s machines, however, are built to provide temperatures up to 120°C, opening the door to a much wider set of industrial uses: washing and sterilization, drying and evaporation stages, certain chemical and food-processing steps, and district heating supply.

This high-temperature capability matters because industrial heat is one of the toughest sectors to decarbonize. Many processes still rely on direct combustion of fossil fuels because they require high temperatures and continuous operation. High-temperature heat pumps reduce that dependence by providing an electrified pathway to deliver useful process heat, especially as grids and electricity supplies decarbonize.

Small factory, multiplied benefits

The direct emissions savings from the Herstal geothermal system — estimated at around 32 tonnes of CO2 avoided per year compared to a conventional gas boiler — may appear modest on their own. But that figure reflects only the onsite heating substitution. The broader climate value is realized when the heat pumps manufactured at CircularSteam1 are sold and deployed across other industrial and district heating sites. Each installed pump can replace fossil-fired heat at client locations, multiplying the emissions avoided across sectors.

There is also a strong local development case. CircularSteam1 is expected to create 77 skilled jobs in Herstal, and that employment will ripple into local supply chains: drilling and geotechnical services, maintenance, electrical installations, and logistics. Importantly, the site sits on a 25,000 m² property containing former mining galleries, a symbolic and practical reuse of industrial land that links the region’s extractive past to a renewable-energy future.

How the geothermal system supports circular operation

CircularSteam1’s name hints at its core principle: circularity. The plant demonstrates a closed-loop thermal economy in several ways:

- Geothermal probes provide a steady source and sink for heat without extracting groundwater.

- Heat from testing the heat pumps is captured and reinjected, returning energy to the subsurface rather than wasting it to the atmosphere.

- The manufacturing itself delivers technology that helps other facilities reduce their fossil fuel consumption.

This circular approach preserves subsurface thermal resources and reduces the need for external fuels. It also lowers the plant’s operational carbon footprint while giving customers a live example of geothermal-integrated manufacturing.

Design choices: why 30 probes at 140 meters?

Selecting drilling depth, probe count, and layout is always a trade-off among land availability, desired thermal capacity, drilling costs, and long-term thermal management. For a commercial production building sized at about 7,000 m² and targeting roughly 200 MWh/year of thermal energy from the ground, 30 probes at 140 meters is consistent with typical shallow geothermal designs that aim to meet a facility’s baseline heating and cooling loads without over-exploiting the ground.

Drilling to 140 meters helps access more consistent temperatures and increases the heat exchange surface area per probe, reducing the total number of boreholes needed compared to shallower designs. Those choices, combined with reinjection of test heat, help ensure the system won’t suffer thermal depletion and can operate effectively for decades.

Repurposing mining galleries: a practical advantage

The Herstal site includes former mining galleries — underground infrastructures that present an opportunity. Repurposing degraded or brownfield industrial zones is beneficial in many ways:

- It reduces pressure on undeveloped land.

- It leverages existing knowledge about subsurface conditions, potentially lowering geotechnical uncertainty.

- It creates a narrative bridge from historical industry to modern clean-energy manufacturing.

For regions with industrial legacies, projects that convert old mining or heavy-industrial areas into green manufacturing hubs offer both symbolic and practical pathways for economic transition.

Scaling manufacturing for Europe’s heat pump needs

Armstrong’s managing director suggested Europe needs roughly fifty plants like CircularSteam1 to meet decarbonization targets by 2050. The logic behind that claim lies in manufacturing scale and regional distribution. To enable widespread adoption of industrial heat pumps, Europe will likely need:

- Increased production capacity to reduce lead times and lower component costs through learning-by-doing.

- Distributed manufacturing to serve regional markets faster and to build local supply chains and employment.

- Demonstration sites that validate business models and help standardize installation, maintenance, and performance expectations.

Whether the precise number is 50 or some other figure, the takeaway is that scaling the production of high-temperature heat pumps is central to electrifying industrial heat across many sectors.

Challenges and risks to consider

CircularSteam1 is an important prototype, but replication at scale will face challenges:

- Electricity carbon intensity: the climate benefits of heat pumps depend on clean electricity. In regions where grid power is still carbon-heavy, electricity-driven heat can shift emissions rather than eliminate them.

- Capital intensity: high-temperature heat pumps require investment. Policy support, carbon pricing, and procurement incentives will help bridge the upfront cost gap versus incumbent fossil systems.

- Site integration: replacing boilers is not always plug-and-play; some industrial processes require redesigns or hybrid setups combining heat pumps with backup systems.

- Supply chains: expanding manufacturing to hundreds or thousands of units per year will demand robust supply chains for compressors, heat exchangers, controls, and power electronics.

- Thermal resource management: even closed-loop fields need careful thermal balance planning; reinjection strategies and monitoring are essential to avoid long-term performance decline.

Policy levers that accelerate geothermal uptake

Governments and regional authorities can accelerate projects like CircularSteam1 with targeted policy measures:

- Financial support for demonstration and early commercial manufacturing, including grants, low-interest loans, and tax breaks.

- Industrial electrification roadmaps that give manufacturers clarity on future electrification demand.

- Public procurement of low-carbon heat, which creates first-market opportunities for heat pump adoption.

- Workforce training programs for geothermal drilling, heat pump installation, and maintenance to ensure skilled labor availability.

- Standards and certification to build trust in performance, reliability, and safety of high-temperature heat pumps and geothermal systems.

A role for district heating and industrial clusters

Geothermal-powered heat pumps can find particularly fertile ground in places with district heating networks or tightly clustered industries. Industrial parks and urban districts can benefit from centralized manufacturing and shared heating infrastructure:

- District heating systems can absorb medium- and high-temperature heat produced by heat pumps and displace regional gas boilers.

- Industrial clusters can share waste heat and provide flexible lower-temperature sources that heat pumps can upgrade.

- Shared procurement and installation frameworks can reduce costs and speed adoption across multiple facilities.

Lessons for other regions

Herstal’s CircularSteam1 offers a replicable blueprint for other regions with industrial histories:

- Locate manufacturing near industrial demand centers to shorten supply chains.

- Use local thermal resources — shallow geothermal or waste heat — to power manufacturing operations and showcase decarbonization.

- Redevelop brownfield sites to bring new economic activity without expanding land use.

- Pair manufacturing with workforce development to ensure local benefits are direct and lasting.

- Design projects with circular thermal practices — capture, reuse, and reinject heat wherever possible.

The long view: building thermal resilience

Looking toward 2050, deep decarbonization requires more than isolated projects — it needs systems thinking. CircularSteam1 contributes to three system-level goals:

- Electrify process heat where feasible to align industry with decarbonizing electricity grids.

- Localize renewable thermal resources, reducing reliance on imported fuels and bolstering resilience.

- Grow manufacturing capacity for low-carbon technologies to meet rising demand and avoid supply bottlenecks.

By manufacturing machines that enable others to cut emissions while using geothermal energy itself, the Herstal plant embodies a multiplier effect: the site’s own low-carbon operation is matched by the potential emissions savings from every heat pump it ships.

Conclusion: a geothermal pivot with outsized symbolic value

CircularSteam1 won’t single-handedly decarbonize Europe’s industry. But its design — high-temperature heat pump production powered by a closed-loop geothermal system on a repurposed mining site, co-financed by the EU and creating local skilled jobs — offers a compact, concrete example of how the thermal transition can be done. It shows how geothermal energy can be integrated into industrial manufacturing not only as a clean supply of onsite heat and cooling but as part of a circular thermal economy that keeps energy flows in balance.

If Europe intends to replace fossil-fired heat across manufacturing and urban systems, it will need many more projects that combine manufacturing scale, renewable thermal supply, workforce development, and supportive policy. CircularSteam1 is one such project, a prototype that, if replicated, will help unlock a broader shift away from combustion-based industrial heat toward electrified and geothermal-powered solutions.

Source: Belgshare 

Connect with us:LinkedIn, X

Subscribe to our newsletter