Geothermal power offers long-life assets and dependable, low-carbon electricity, yet its deployment has progressed more slowly than its resource potential would suggest. The main challenges have not been technical capability, but making projects work economically within today’s development and power-market frameworks.
As interest in geothermal grows, driven by advances in exploration workflows, next-generation concepts, and rising demand for reliable, low-carbon power, including from energy-intensive digital infrastructure such as data centers, the ability to extract more value from developed geothermal resources becomes increasingly important. In this context, low-temperature organic Rankine cycle (ORC) technology can be applied across several geothermal use cases to increase power output, improve efficiency, and enable additional development pathways. The following applications illustrate where low-temperature ORCs can create the greatest value today.
Key Takeaways
- Low-temperature ORC technology enables more efficient geothermal power generation across multiple applications, including existing geothermal plants, district heating systems, produced water from oil and gas operations, and selective localized developments.
- Incremental efficiency gains can materially improve project economics by increasing power output from already developed geothermal resources
- As electricity demand and power prices rise, the value of additional geothermal power output increases.
- Technologies that improve heat utilization support the scalable, cost-effective expansion of geothermal power.
Where Low-Temperature ORCs Can Create the Greatest Value
1. Increasing Efficiency and Power Output at Existing Geothermal Power Plants
Many geothermal power plants reject usable heat after the primary power cycle. Low-temperature ORCs can be deployed downstream to convert this remaining heat into additional electricity without requiring new wells or changes to reservoir operation.
By increasing overall plant efficiency and total power output from the same geothermal resource, bottoming cycles offer a practical and low-risk way to improve project economics and maximize asset value at operating geothermal facilities.
2. Combined Heat and Power in District Heating Systems
Geothermal resources are often used for district heating in Europe, where heat delivery is frequently the primary project objective. District heating networks operate across a range of supply temperatures, with modern systems increasingly designed for lower-temperature operation.
Where geothermal resource temperatures are sufficiently high—typically closer to ~100 °C—low-temperature ORCs can be integrated upstream of heat delivery to generate electricity before supplying heat to the district heating network. In this configuration, power generation extracts part of the available thermal energy and can be considered part of the heat-conditioning process, while remaining heat continues to meet district heating requirements. District heating return water can then often be used for the cooling side of the ORC.
As district heating temperatures trend lower and electricity markets place greater value on reliable generation, this power-first CHP configuration represents a growing opportunity in suitable locations.
3. Power Generation from Produced Water in Oil and Gas Operations
Produced water from oil and gas operations often contains recoverable thermal energy that is discharged without productive use. In these settings, low-temperature ORCs can convert waste heat into electricity using existing wells and surface infrastructure, reducing development complexity.
In the United States alone, oil and gas operations produce on the order of 25 billion barrels of hot water annually, the majority of which is reinjected after production. Subsurface temperature mapping shows that many areas of the United States reach temperatures of around 100 °C or higher at a depth of~3km, typical of oil and gas wells, placing a significant share of this heat squarely within the operating range of low-temperature ORC systems.
Source: ORNL, “Geothermal Energy Production with Co-produced and Geopressured Resources,” Fig. 4 (based on SMU geothermal temperature mapping).
This application is particularly relevant for mature or late-life assets, where incremental power generation can improve overall site efficiency and support energy transition objectives without interfering with core operations.
4. Selective Development of Localized and Lower-Temperature Geothermal Resources
In regions with favorable geology, such as shallow reservoirs and lower pumping requirements, localized geothermal resources can support small-scale power generation using low-temperature ORC technology with competitive project economics. Iceland is a well-known example, where geothermal heat is abundant and accessible at relatively shallow depths, enabling power generation from both high- and lower-temperature resources with comparatively lower development costs.
In some projects, geothermal drilling confirms usable heat at temperatures below those originally targeted for large-scale power generation. In such cases, low-temperature power systems can provide an additional option for localized electricity production. By enabling power generation from accessible, lower-temperature geothermal resources, these systems expand the range of locations where geothermal electricity projects can be considered beyond the limited set of high-temperature developments. As electricity prices rise, the value of incremental power output from these resources increases, improving payback in favorable locations.
What This Means for Geothermal Power Development
Geothermal power remains underdeveloped relative to its importance as a source of reliable, low-carbon electricity. Its broader deployment depends not on any single breakthrough, but on a combination of supportive market conditions, project economics, and technologies that allow geothermal resources to be developed more efficiently across a wider range of project configurations.
Within this context, low-temperature ORC technology plays an enabling role. By increasing power output from existing geothermal plants, integrating electricity generation into district heating systems, converting waste heat from co-produced fluids, and supporting selective localized developments, low-temperature ORCs help improve the overall utilization of geothermal heat. These incremental gains do not change the fundamentals of geothermal development, but they do strengthen project economics and expand the set of viable development options.
As electricity demand grows and reliable, low-carbon generation becomes increasingly valuable, the ability to extract more power from developed geothermal resources takes on greater importance. Technologies that improve efficiency, reduce marginal costs, and integrate flexibly into existing systems will be central to how geothermal power evolves from a proven niche into a more widely deployed part of the energy mix.
Explore Further
Learn more about Climeon’s low-temperature ORC technology and how it is applied across geothermal power projects.
