The Untapped Power of Low-Temperature Geothermal Heat for Industry

Industrial processes account for a significant portion of global energy consumption, much of which still relies on fossil fuels for heating. While high-temperature geothermal resources have long been harnessed for electricity generation, a lower-temperature, yet widely abundant, resource remains largely underutilized. Low-temperature geothermal resources—typically defined as reservoirs with temperatures below 150°C—offer a direct, reliable, and cost-effective source of heat for a vast range of industrial applications. From food processing and chemical manufacturing to textile production and greenhouse agriculture, these resources can replace natural gas, oil, and coal, driving down both operating costs and greenhouse gas emissions. This article explores the nature of low-temperature geothermal resources, their industrial potential, the technologies that unlock them, and the path forward for broader adoption.

What Defines Low-Temperature Geothermal Resources?

Geothermal energy is the thermal energy stored within the Earth’s crust. Resources are typically classified by temperature. Low-temperature geothermal resources are those where the fluid temperature is below 150°C (300°F). This contrasts with moderate-temperature (150–200°C) and high-temperature (over 200°C) systems that are typically used for conventional power generation. Low-temperature resources manifest in two primary forms:

  • Hydrothermal systems – Naturally occurring hot water or steam trapped in porous rock or fractured formations. These are often found at shallow depths (a few hundred meters to 2 km) and are the most common and economical to develop.
  • Sedimentary basins – Deep sedimentary rock layers containing warm water, often in regions without volcanic activity. These basin-scale resources are widely distributed across continents and can be tapped using conventional water wells.
  • Enhanced Geothermal Systems (EGS) at lower temperatures – While EGS traditionally aims at high temperatures, recent research explores engineering low-permeability, hot rock formations at moderate depths to create artificial reservoirs.

Globally, the majority of accessible geothermal resources are low-temperature. Countries such as the United States, China, Turkey, Iceland, and numerous European nations have extensive low-temperature fields that are currently underdeveloped for industrial use. A 2023 IRENA report estimates that direct use of geothermal heat could meet 5–10% of global industrial heat demand by 2050, with low-temperature resources providing the bulk of that potential.

Industrial Applications: Where Low-Temp Geothermal Excels

Industrial processes require heat at a wide range of temperatures. Many of these—drying, evaporation, pasteurization, washing, space heating—operate at temperatures well under 150°C, making them ideal candidates for low-temperature geothermal direct use. Below are the most promising industrial sectors and specific applications.

Food and Beverage Processing

The food industry relies heavily on thermal energy for cooking, blanching, pasteurization, sterilization, and cleaning. Low-temperature geothermal can supply hot water (60–120°C) for these tasks. In New Zealand, a geothermal food-processing plant uses 120°C water for milk pasteurization and spray drying, cutting natural gas consumption by 90%. Similarly, in Japan, geothermal fluid is used to heat greenhouses for year-round vegetable production. Key advantages include stable heat supply (unaffected by weather) and reduced exposure to volatile fossil fuel prices.

Drying and Curing of Materials

Drying is energy-intensive, often requiring air at 50–120°C. Low-temperature geothermal can heat drying chambers or provide pre-heated air for:

  • Wood and timber – Kiln drying using geothermal water at 80–100°C reduces costs and improves quality.
  • Agricultural products – Drying grains, fruits, vegetables, and herbs with geothermal heat preserves nutrients and extends shelf life.
  • Ceramics and bricks – In regions with clay deposits, geothermal air at 80–120°C can cure bricks and tiles.
  • Textiles – Drying fabric after dyeing and finishing uses large amounts of energy; geothermal can provide this heat directly or via heat exchangers.

Chemical and Pharmaceutical Manufacturing

Many chemical reactions require precise temperatures between 80°C and 140°C. Low-temperature geothermal can be used for reactor heating, distillation, evaporation, and solvent recovery. In China, a chemical plant uses geothermal water at 110°C to produce boric acid, achieving a 40% reduction in coal use. The pharmaceutical sector can also use geothermal steam for sterilization of equipment and clean-in-place systems.

Greenhouse Heating and Aquaculture

Although not strictly “industrial,” these are large-scale commercial operations that benefit from geothermal heat. Greenhouses for flowers, vegetables, and fruits maintain temperatures around 15–25°C even in winter, using geothermal fluid circulated through pipes and radiators. Aquaculture facilities raising tilapia, shrimp, or salmon use geothermal water to maintain optimal water temperatures, increasing growth rates and reducing mortality. Integrated systems, where geothermal effluent cascades from greenhouse to fish ponds, maximize thermal efficiency.

Textile Production

The textile industry consumes large volumes of hot water for dyeing, bleaching, and finishing. Temperatures typically range from 60–100°C. Geothermal water can be used directly or pre-heat process water, reducing fossil fuel consumption. A textile mill in Turkey’s Denizli region has used geothermal heat since the 1980s, saving an estimated $500,000 per year in energy costs.

District Heating for Industrial Parks

Low-temperature geothermal is not limited to a single factory; it can serve entire industrial parks via district heating networks. For example, the town of Klamath Falls, Oregon, uses geothermal water at 90–110°C to heat multiple buildings, including the Oregon Institute of Technology campus and nearby industrial facilities. Such networks distribute heat efficiently and reduce the capital burden for individual companies.

Technologies for Harnessing Low-Temperature Geothermal

Deploying low-temperature geothermal in industry requires appropriate extraction and utilization technologies. The most common approaches include:

Direct Use Systems

In direct use, geothermal fluid is pumped from a production well and passed through a heat exchanger before being used in the industrial process. After transferring its heat, the cooled fluid is either reinjected into the reservoir (to maintain pressure and sustainability) or discharged (where permitted). Direct use is simplest and most efficient when the geothermal temperature matches the process requirement.

Geothermal Heat Pumps (GHPs)

Where the resource temperature is too low (10–30°C), geothermal heat pumps can upgrade the heat to a usable level (50–70°C) using a vapor-compression cycle. GHPs are particularly suited for space heating, pre-heating process water, and low-temperature drying. While they require electricity to run, the coefficient of performance (COP) is typically 3–5, meaning 3–5 units of heat are delivered per unit of electricity input. This makes GHPs highly efficient even for low-temperature resources.

Cascading Use

Cascading involves using geothermal fluid sequentially in multiple processes at decreasing temperatures. For example, water at 110°C might first be used for chemical reaction heating, then at 80°C for drying, then at 50°C for greenhouse heating, and finally at 30°C for aquaculture. This maximizes energy extraction and improves overall economics. Cascading is especially relevant for industrial parks centered around a geothermal wellfield.

Hybrid Systems

Combining low-temperature geothermal with other renewables (solar thermal, biomass) or with waste heat from industrial processes can create hybrid systems that provide reliable, year-round heat. For instance, a food processing plant in Switzerland uses geothermal heat supplemented by a biomass boiler during peak demand, achieving 100% renewable heat supply.

Advantages and Economic Benefits

Switching to low-temperature geothermal heat offers numerous advantages over conventional fossil-fuel boilers and even other renewables:

  • Price stability – Geothermal heat has no fuel cost and is not subject to price volatility. Once the initial infrastructure is built, operating costs are predictable and low (mainly electricity for pumps and maintenance).
  • High capacity factor – Geothermal resources provide heat 24/7, regardless of weather. This makes them ideal for continuous industrial processes that cannot tolerate intermittent supply.
  • Reduced carbon footprint – Direct use of geothermal heat can cut CO₂ emissions by 70–90% compared to natural gas. Further reductions are possible if the electricity used for pumps is renewable.
  • Local energy independence – Many industrial sites are located on or near geothermal resources, reducing dependence on imported fuels and enhancing energy security.
  • Job creation and economic development – Developing geothermal resources stimulates local employment in drilling, engineering, construction, and operation. It also attracts industries seeking low-cost, stable energy.

According to the U.S. Department of Energy, the levelized cost of heat (LCOH) from low-temperature geothermal can be as low as $15–30 per MWh, compared to $30–60 for natural gas (depending on region and gas prices). This makes geothermal highly competitive, especially in areas with high fossil fuel taxes or carbon pricing.

Barriers and Challenges to Adoption

Despite the clear benefits, several barriers hinder the widespread industrial use of low-temperature geothermal resources. Understanding these challenges is essential for developing effective solutions.

High Upfront Capital Costs

Drilling geothermal wells is expensive, typically costing $1–5 million for a production/reinjection pair, depending on depth and geology. Exploration risk (dry holes) can deter investment. However, with proper geological surveys and public-private partnerships, these risks can be mitigated. Government subsidies, tax credits, and innovative financing models (e.g., geothermal heat purchase agreements) help lower the initial barrier.

Resource Identification and Characterization

Not all industrial sites have accessible geothermal resources. Detailed resource assessment—including temperature, flow rate, water chemistry, and reservoir sustainability—is required before commitment. Water quality (scaling, corrosion) can also be an issue. For example, saline or silica-rich geothermal fluids may require expensive heat exchangers and treatment. Yet many sedimentary basins have clean, non-corrosive water at suitable temperatures.

Regulatory and Permitting Hurdles

Geothermal development involves permitting for drilling, water extraction, reinjection, and land use. In some jurisdictions, this process can take years. Streamlining permitting for low-temperature geothermal (which poses fewer environmental risks than high-temperature systems) would accelerate deployment. The European Union’s revised Renewable Energy Directive includes measures to simplify geothermal permitting as part of the Green Deal.

Lack of Awareness and Technical Expertise

Many industrial facility managers are unaware of the potential of low-temperature geothermal or lack in-house expertise to evaluate it. Outreach programs, case study databases, and technical assistance centers can bridge this gap. The International Geothermal Association (IGA) and national geothermal associations offer training and resources for potential users.

Integration with Existing Processes

Retrofitting geothermal heat into an existing factory may require modifications to piping, heat exchangers, and control systems. However, greenfield industrial parks can be designed from the start for geothermal integration, significantly reducing cost. Modular, containerized geothermal heat supply systems are now emerging that simplify installation.

Successful Case Studies Around the World

Real-world examples demonstrate the viability of low-temperature geothermal in industry and provide replicable models.

Oregon Institute of Technology (Klamath Falls, USA)

The Oregon Tech campus has used geothermal heat since the 1960s. Two wells at 90–110°C provide heat for the entire campus, including classrooms, laboratories, and a student center. In addition, the geothermal fluid supplies heat to a nearby food-processing plant and a greenhouse. This district heating system has saved the university over $1 million annually in avoided natural gas costs.

Reykjanesbær, Iceland

Iceland is a leader in geothermal use. The town of Reykjanesbær utilizes low-temperature geothermal (100–130°C) to supply heat to fish processing plants, a salt production facility, and greenhouses. The heat is distributed through a district network, and cascading is employed so that spent water goes to snow melting and aquaculture. This system has transformed a region with no fossil fuel use in its industrial heat supply.

Yangbajing, Tibet

In addition to a geothermal power plant, the Yangbajing field (water at 100–130°C) provides heat for a greenhouse and a cheese factory. The success has spurred interest in replicating the model for other high-altitude, off-grid industrial sites in China.

St. Gallen, Switzerland

A district heating network in St. Gallen, fed by a low-temperature geothermal well at 115°C, supplies heat to a brewery, a chocolate factory, and a hospital. The project overcame initial public opposition by demonstrating safety and environmental benefits. It now supplies 60 GWh/year of renewable heat, cutting 12,000 tonnes of CO₂ annually.

The Road Ahead: Scaling Up Low-Temperature Geothermal

The future of low-temperature geothermal in industry is promising, but it requires a concerted effort from policymakers, industry, and researchers.

Technological Innovations

Advances in drilling technology (diamond drilling, directional drilling) are reducing costs. Closed-loop geothermal systems, which circulate a working fluid through a downhole heat exchanger without extracting water, eliminate water handling issues and can be deployed in nearly any geology. Research into nanoparticle-based heat transfer fluids may further improve efficiency. Meanwhile, advanced modeling and machine learning are improving resource characterization, lowering exploration risk.

Policy and Financial Incentives

To unlock the industrial potential, governments should provide:

  • Investment tax credits or grants for geothermal drilling and heat supply systems.
  • Streamlined permitting for low-temperature direct use projects.
  • Carbon pricing that makes fossil heat more expensive, improving geothermal competitiveness.
  • Publicly available geological data and resource maps to guide site selection.
  • Risk mitigation programs (e.g., insurance for dry wells or underperformance).

The U.S. Inflation Reduction Act includes a 30% investment tax credit for geothermal heat pumps and direct-use systems, which has already spurred new projects. Similar policies in the EU, Japan, and Chile are creating momentum.

Integration with Industrial Symbiosis

Low-temperature geothermal can be a cornerstone of industrial symbiosis—where waste heat and resources are shared among companies. An industrial park designed around a geothermal resource can cascade heat from high-temperature chemical processes to lower-temperature food processing and space heating, maximizing total efficiency. Digital tools for heat mapping and matchmaking can identify such synergies.

Education and Workforce Development

Training programs for geothermal technicians, engineers, and project developers are needed to expand capacity. Partnerships between universities, geothermal companies, and industry associations can create curricula and certifications. The Geothermal Rising organization offers professional development and networking opportunities. As more industrial companies become familiar with the technology, adoption will accelerate.

Conclusion

Low-temperature geothermal resources represent a vast, clean, and reliable heat source that can transform industrial processes worldwide. With temperatures under 150°C, these resources can meet a substantial portion of industrial heat demand—from food processing and drying to chemical manufacturing and district heating. While challenges such as upfront costs, resource identification, and regulatory hurdles remain, technological advancements, policy support, and successful case studies from Iceland, the United States, China, and Europe are proving the value. As industries seek to decarbonize and reduce exposure to fossil fuel price volatility, low-temperature geothermal offers a compelling path forward. The potential is not just technical; it is economic and environmental. By tapping into the heat beneath our feet, we can make industrial production cleaner, more resilient, and more competitive in a low-carbon world.