Geothermal Power Plant Equipment: Turbines, Pumps, Heat Exchangers and Leading Suppliers

Geothermal Power Plant Equipment: Turbines, Pumps, Heat Exchangers and Leading Suppliers

Geothermal power plants convert heat stored beneath the Earth’s surface into reliable, low-carbon electricity. Unlike solar and wind generation, geothermal plants can operate continuously, making them an important source of baseload renewable power. However, geothermal development is technically demanding because the resource is often hot, corrosive, mineral-rich, and variable in pressure and chemistry. The equipment used in a geothermal power plant must therefore be engineered for durability, high availability, and efficient heat conversion under challenging operating conditions.

The central equipment package in a geothermal power plant generally includes turbines or Organic Rankine Cycle expanders, pumps, heat exchangers, separators, condensers, reinjection systems, electrical generators, transformers, switchgear, and control systems. Each component must be selected in relation to the characteristics of the geothermal resource and the chosen power-cycle configuration. Flash plants, direct-steam plants, and binary plants all use different combinations of equipment, and the correct selection has a major effect on project cost, efficiency, reliability, and long-term operating performance.

This article examines the main types of geothermal power plant equipment, explains how turbines, pumps, and heat exchangers function within the plant, identifies leading suppliers, and outlines the procurement considerations that developers and engineering contractors should prioritize.

Why equipment selection matters

Geothermal projects are highly site-specific. A resource’s temperature, pressure, flow rate, chemistry, gas content, and reservoir behavior determine whether a flash, direct-steam, or binary plant is technically and economically appropriate. A high-temperature resource may support a flash steam plant, while a lower-temperature resource may be better suited to a binary or Organic Rankine Cycle system.

Equipment selection cannot therefore be treated as a generic power-plant purchase. It must be integrated with reservoir engineering, well design, brine chemistry management, cooling strategy, environmental requirements, and grid-connection needs. A turbine that performs well in one geothermal field may suffer from scaling, corrosion, or noncondensable-gas problems in another. Similarly, a pump or heat exchanger that is suitable for clean water may fail prematurely when exposed to geothermal brine containing chlorides, silica, sulfides, or dissolved gases.

For procurement teams, the most consequential equipment decisions usually concern the turbine or ORC expander, production and injection pumps, preheaters and evaporators, condensers, separators, gas-removal systems, electrical equipment, and corrosion-resistant piping and valves. These components determine not only the plant’s ability to generate electricity but also its availability, maintenance burden, water consumption, and lifetime operating cost.

Main geothermal plant technologies

Flash steam plants

Flash steam plants are generally used where geothermal fluid arrives at sufficiently high temperature and pressure. As the geothermal fluid rises from the reservoir and experiences a reduction in pressure, part of it flashes into steam. This steam is separated from the remaining liquid brine and directed to a steam turbine, where it expands and generates mechanical power.

In a single-flash plant, the separated brine is normally reinjected into the reservoir after its heat has been extracted. In a double-flash plant, the separated brine is flashed again at a lower pressure to produce additional low-pressure steam. This increases energy recovery from the same geothermal fluid, but it also adds flash vessels, piping, controls, and turbine complexity.

Typical flash-plant equipment includes steam separators, scrubbers, high- and low-pressure steam turbines, condensers, cooling systems, condensate pumps, reinjection pumps, brine-handling equipment, and noncondensable-gas removal systems. The plant also requires generators, transformers, switchgear, protection systems, and plant controls.

Flash systems are most attractive for high-temperature conventional hydrothermal resources. They generally have lower capital costs than binary plants because they use fewer components and can produce more power per well. However, their performance depends heavily on maintaining stable steam conditions and managing scaling, corrosion, and gas content.

Direct steam plants

Direct-steam plants use dry steam produced directly by the geothermal reservoir. Because the steam reaches the turbine without first passing through a flash vessel, the plant configuration is relatively simple. These plants can be highly efficient where a dry-steam resource is available, although such resources are relatively uncommon globally.

The equipment scope is broadly similar to that of a flash plant, but the design must account for steam quality, mineral carryover, and noncondensable gases. Turbine selection, separator design, and corrosion control become especially important because geothermal steam contacts the power-cycle equipment directly.

Direct-steam plants require robust steam separation and filtration systems to prevent mineral particles from damaging turbine blades. They also require effective condensate recovery and reinjection systems to maintain reservoir pressure and minimize environmental impacts.

Binary and ORC plants

Binary plants transfer heat from geothermal brine to a secondary working fluid, such as an organic fluid in an Organic Rankine Cycle or ammonia in a Kalina-type cycle. The working fluid vaporizes, expands through a turbine or expander, condenses, and is pumped back through the closed loop. The geothermal brine itself does not normally pass through the turbine.

Binary systems are commonly selected for lower-temperature resources and for brine that is better kept in a closed loop to reduce scaling, corrosion, and emissions. They are also useful for recovering additional energy from the separated brine leaving an existing flash plant.

A binary plant’s central equipment package includes brine-to-working-fluid heat exchangers, an ORC turbine or radial or axial expander, a working-fluid pump, an air-cooled or water-cooled condenser, and, where justified, a recuperator. The plant also requires working-fluid storage, charging, and recovery systems, along with brine reinjection pumps and piping.

Turboden describes its ORC systems as closed-loop technology that transfers geothermal heat to an organic working fluid, which vaporizes and drives a turbine to generate electricity. The company supplies ORC turbines, heat exchangers, air-cooled condensers, and control systems as part of its geothermal equipment offering.

Geothermal turbines and expanders

The turbine is the heart of the power-conversion system. In flash and direct-steam plants, it converts geothermal steam energy into mechanical shaft power. In ORC plants, it converts the energy of vaporized working fluid into shaft power. The turbine is directly connected to an electrical generator, which converts mechanical energy into electricity.

Steam turbines

Geothermal steam turbines must tolerate wet steam, dissolved minerals, corrosive gases, and variable resource conditions. Their design must address erosion, deposition, blade fouling, and noncondensable-gas handling. These challenges make geothermal turbines more specialized than conventional steam turbines used in fossil-fuel power plants.

Fuji Electric is a prominent supplier of geothermal turbines. The company supplies geothermal turbines with capacities up to 160 MW and states that it has delivered approximately 60 geothermal turbines in Japan and internationally. Mitsubishi Heavy Industries is another major global turbine and power-plant supplier. The European Commission identifies Mitsubishi, Ormat, and Fuji as dominant companies in the geothermal turbine market.

Ansaldo Energia also supplies turbines and provides services spanning mechanical design, installation, and commissioning. Siemens Energy and GE Vernova are also listed among major companies operating in the geothermal power equipment market. These suppliers are relevant for developers seeking established turbine technology, global service networks, and proven experience in large-scale power generation.

For a flash plant, buyers should evaluate turbine efficiency at expected steam conditions, tolerance to wetness and scaling, spare-parts availability, control-system integration, and the supplier’s experience with comparable geothermal fields. They should also consider whether the turbine can operate efficiently across a range of resource conditions, because geothermal reservoirs may decline or change over time.

ORC expanders

ORC systems use a working fluid rather than geothermal steam. The expander may be an axial turbine, radial turbine, screw expander, or other machine, depending on capacity, pressure ratio, and fluid selection. ORC expanders are designed to operate efficiently with organic working fluids at relatively low temperatures and pressures.

Turboden supplies tailor-made axial multistage turbines with stated isentropic efficiency above 90 percent. The company also supplies in-house air-cooled condensers, heat exchangers, and control systems. Turboden has supplied a 29 MWe ORC plant for Energy Development Corporation’s Palayan Bayan expansion in the Philippines. The system was designed to recover heat from brine downstream of an existing flash plant, demonstrating how ORC technology can increase output from an existing geothermal field.

Ormat is another major integrated supplier. It provides equipment and services ranging from individual components to turnkey geothermal power plants tailored to site conditions and resource characteristics. Ormat’s integrated approach can be attractive to developers that want a single supplier to manage the power-conversion system, controls, and plant performance.

Turbine procurement checklist

A strong turbine specification should cover design steam or working-fluid conditions, rated and part-load performance, guaranteed output, heat rate, and availability. It should also address materials and coating requirements, erosion and scaling allowances, noncondensable-gas handling, control-system and SCADA integration, factory testing, site commissioning, maintenance intervals, spare-parts strategy, and performance guarantees.

Buyers should require clear definitions of guaranteed net output, ambient conditions, steam or brine conditions, auxiliary power consumption, and availability assumptions. These details prevent disputes during commissioning and ensure that equipment suppliers are accountable for real plant performance rather than laboratory or nameplate figures.

Geothermal pumps

Pumps are essential across the geothermal value chain. They move production fluid, condensate, cooling water, reinjection brine, and ORC working fluid. Their reliability directly affects plant availability, reservoir management, and operating cost.

Production and injection pumps

Downhole production pumps can prevent premature flashing in the wellbore, maintain pressure, and increase production flow in suitable reservoirs. They are particularly important in resources where natural artesian flow is insufficient or where reservoir pressure must be managed carefully.

Reinjection pumps return cooled brine or condensate to the reservoir. Reinjection helps sustain reservoir pressure, manage fluid disposal, and reduce the risk of surface contamination. The pumps must withstand high temperatures, abrasive solids, scaling minerals, and corrosive chemistry.

Materials selection, mechanical-seal design, cooling arrangements, and condition-monitoring capability are critical for geothermal pump reliability. A pump that performs well in a conventional industrial application may suffer rapid seal wear or corrosion when exposed to geothermal brine at high temperature.

Surface process pumps

Typical surface pump duties include condensate extraction and hotwell pumps, cooling-water circulation pumps, reinjection pumps, ORC working-fluid pumps, chemical-dosing pumps, firewater and utility-water pumps, and noncondensable-gas compression or ejector systems.

ABB identifies condensate, hotwell, reinjection, and cooling-water circulation pumps, cooling-tower fans, and gas-rejection compressors as typical motor-driven applications in geothermal plants. ABB also supplies high- and low-voltage motors and variable-speed drives for these applications.

Variable-speed drives can improve energy efficiency by matching pump output to actual process demand. They can also reduce mechanical stress during startup and shutdown, which is valuable in geothermal plants where operating conditions may change as the reservoir evolves.

Pump suppliers

Sulzer is a leading supplier of pumps for geothermal power generation. The company provides pumps across major geothermal plant processes and supplies multistage canned vertical pumps for ORC applications. Sulzer states that it has become a preferred supplier of pump technology for geothermal applications, supported by decades of pump-design and engineering experience.

Flowserve offers geothermal pumps and sealing systems, supported by technical and field-service capabilities. ABB supplies motors, drives, control, monitoring, and protection equipment for pump applications. HYDAC supplies components associated with rotating equipment, including heat exchangers, filters, separators, and lubrication systems.

Pump specification priorities

Procurement teams should specify fluid temperature, pressure, flow, and chemistry, as well as solids content and scaling tendency. They should also define required head and efficiency across the operating range, minimum flow and cavitation margins, seal-plan compatibility with geothermal brine, material compatibility, variable-speed-drive requirements, redundancy, spare-parts availability, and remote-monitoring capability.

For ORC plants, the working-fluid pump is particularly important because it pressurizes the low-boiling-temperature liquid and drives the closed power cycle. A failure in this pump can shut down the entire ORC unit, making redundancy, spare-parts availability, and condition monitoring especially valuable.

Heat exchangers and condensers

Heat exchangers determine how efficiently geothermal heat is transferred into the power cycle. In binary plants, they are central equipment rather than ancillary systems. Their performance has a direct effect on net electrical output, plant efficiency, and operating cost.

Brine heat exchangers

Brine preheaters and evaporators transfer heat from geothermal fluid to the ORC working fluid. The exchanger must resist fouling, scaling, corrosion, thermal cycling, and pressure differentials. Geothermal brine can contain silica, carbonates, sulfides, chlorides, and other compounds that may deposit on heat-transfer surfaces or corrode equipment over time.

Common configurations include shell-and-tube heat exchangers, gasketed plate heat exchangers, welded plate heat exchangers, semi-welded plate heat exchangers, brazed plate heat exchangers, and plate-and-frame units for compact modular plants.

Alfa Laval offers welded plate and shell-and-tube exchangers for geothermal and ORC applications. The company states that ORC projects commonly use compact plate-based equipment for evaporation, condensation, and recuperation. Kelvion supplies shell-and-tube and plate heat exchangers for power and energy applications, including geothermal plants. HYDAC’s FUNKE brand offers gasketed plate and shell-and-tube heat exchangers for geothermal and ORC or Kalina duties.

The choice between plate and shell-and-tube exchangers depends on brine chemistry, pressure, temperature, fouling risk, maintenance access, and required thermal duty. Plate exchangers can offer high heat-transfer efficiency and compact footprint, while shell-and-tube exchangers may be preferred where robustness, high pressure, or easier mechanical cleaning is required.

Condensers and cooling systems

Condensers reject heat from the power cycle and enable the working fluid or steam to return to liquid form. The choice between air-cooled and water-cooled condensation has major implications for water use, parasitic load, footprint, capital cost, and performance in hot climates.

Air-cooled condensers are common where water is scarce. They eliminate cooling-tower water consumption but usually require more surface area and fan power. Water-cooled systems can be more compact and efficient where cooling water is available, but they introduce water treatment, blowdown, and environmental-management requirements.

Turboden supplies in-house air-cooled condensers as part of its ORC equipment package. This integrated approach can simplify procurement because the condenser, expander, heat exchangers, and control system are designed to operate together as a coordinated package.

Heat-exchanger procurement checklist

Key requirements include thermal duty and approach temperatures, fouling factors and cleaning strategy, brine chemistry and scaling risk, working-fluid compatibility, design pressure and temperature, welded versus gasketed construction, leak-detection and containment requirements, pressure-drop limits, spare capacity for resource degradation, modularization and transport constraints, and performance guarantees at design and off-design conditions.

Buyers should also consider whether the supplier can provide cleaning systems, replacement plates or tube bundles, and technical support for chemistry-related fouling. In geothermal service, heat-exchanger performance often declines gradually due to scaling, so the design must include sufficient margin to maintain output between cleaning cycles.

Separators, scrubbers, and gas removal

Geothermal fluid often contains steam, brine, dissolved gases, and minerals. Separators remove liquid from steam before it reaches the turbine, protecting blades and improving cycle efficiency. Scrubbers and demisters further reduce moisture and particulate carryover.

Noncondensable gases, especially carbon dioxide and hydrogen sulfide, must be removed from the condenser to maintain vacuum and prevent corrosion. Gas-removal systems may use ejectors, vacuum pumps, compressors, or abatement equipment depending on gas composition and environmental requirements.

ABB identifies gas-rejection compressors as a typical geothermal plant application, while HYDAC supplies gas filters, droplet separators, and heat exchangers for rotating-equipment systems. The design of these systems should account for gas composition, flow variability, corrosion risk, emissions limits, and the need to maintain condenser vacuum under changing plant conditions.

Electrical and control equipment

The electrical package converts mechanical shaft power into grid-compatible electricity and ensures safe, reliable operation. Core equipment includes a synchronous generator, excitation system, transformer, medium- and high-voltage switchgear, protection relays, motor control centers, variable-speed drives, UPS and emergency power systems, SCADA, distributed control systems, and condition-monitoring systems.

ABB supplies generator packages that include cooling systems, terminal boxes, maintenance tools, controls, monitoring, and protection solutions. It also supplies motors and drives for pumps, cooling-tower fans, and gas-rejection compressors. These systems are essential for maintaining stable plant operation, protecting equipment from electrical faults, and ensuring compliance with grid requirements.

For remote geothermal sites, digital monitoring is increasingly valuable. Vibration, temperature, pressure, flow, and chemistry data can support predictive maintenance, reduce unplanned outages, and improve reservoir-management decisions. Remote monitoring is particularly useful where plants are located in isolated areas with limited access to specialized maintenance personnel.

Cost drivers and budgeting

Geothermal project costs are dominated by the resource itself. Exploration, confirmation drilling, well-field development, reservoir stimulation, plant equipment, and construction all contribute to capital expenditure. Unlike wind or solar projects, geothermal development carries substantial geological risk before the plant is built. A developer may spend significant capital on exploration and drilling before knowing whether the resource can support the intended plant capacity.

IRENA reports that geothermal capital costs can reach USD 6,042 per kW in Indonesia, with exploration and drilling uncertainty able to account for up to 50 percent of total project expenditure. This means equipment buyers should not evaluate turbines, pumps, or heat exchangers in isolation from well cost and reservoir risk.

Equipment cost context

NREL’s supply characterization estimates binary power-conversion system capital costs of USD 2,200 to 2,800 per kW, depending on scenario assumptions. NREL also reports production-pump costs of USD 1.0 to 2.0 million per well in the same analysis.

These figures are useful as planning references rather than current turnkey quotations. Actual equipment pricing varies with plant capacity, resource conditions, emissions requirements, location, delivery schedule, local content, and contract structure.

Cost allocation

For a binary geothermal plant, the major capital-cost categories typically include wells and well-field development, power-conversion equipment, pumps and fluid handling, cooling systems, electrical balance of plant, and civil works and installation.

Wells and well-field development are often the largest project risk and cost driver. Power-conversion equipment includes the turbine or expander, generator, heat exchangers, condenser, and working-fluid system. Pumps and fluid handling must be specified for brine chemistry, scaling, and long-term reliability.

Air-cooled systems reduce water use but may increase fan power and footprint. Electrical balance of plant includes the generator, transformer, switchgear, controls, and protection systems. Civil works and installation costs are affected by site access, terrain, seismic conditions, and modularization.

Binary plants tend to have higher capital costs than flash plants because they require more components, operate at lower temperatures, and may require more wells for a given output. However, binary plants can unlock resources that would otherwise be uneconomic, and they can recover additional energy from the brine leaving flash plants.

Leading suppliers by equipment category

Integrated plant suppliers

Ormat provides equipment, services, and turnkey geothermal plant solutions tailored to site and resource conditions. Turboden is a global ORC specialist that supplies ORC turbines, heat exchangers, air-cooled condensers, and control systems. Fuji Electric supplies geothermal turbines, generators, related equipment, and plant-construction capability. Mitsubishi Heavy Industries is a major turbine and power-plant supplier with a broad geothermal technology footprint. Ansaldo Energia supplies turbines and plant-related engineering, installation, and commissioning services.

Pumps and rotating equipment

Sulzer provides a broad geothermal pump portfolio, including multistage canned vertical pumps for ORC service. Flowserve supplies pumps and sealing systems with field-service support. ABB supplies motors, drives, generators, controls, and monitoring systems. HYDAC supplies filtration, separation, lubrication, and heat-transfer components for rotating equipment.

Heat exchangers and thermal equipment

Alfa Laval offers welded plate, gasketed, and shell-and-tube heat exchangers for geothermal and ORC applications. Kelvion supplies shell-and-tube and plate heat exchangers for geothermal and power-generation applications. HYDAC and FUNKE supply gasketed plate and shell-and-tube exchangers, including ORC and Kalina-cycle duties. Turboden supplies in-house ORC heat exchangers and air-cooled condensers.

Procurement strategy

Define the duty before choosing vendors

The first procurement task is to establish a credible heat and mass balance. Developers should define reservoir temperature, production flow, brine chemistry, steam fraction, noncondensable-gas rate, ambient temperature, cooling-water availability, and required net electrical output.

Without these inputs, vendors cannot responsibly guarantee turbine output, heat-exchanger performance, pump reliability, or plant availability. A clear technical basis of design reduces the risk of costly redesign, delayed delivery, and performance shortfalls during commissioning.

Use performance-based specifications

Rather than specifying every component in excessive detail, buyers should define measurable outcomes. These include net electrical output at defined ambient conditions, gross and net plant efficiency, turbine isentropic efficiency, heat-exchanger fouling allowance, pump availability and mean time between overhauls, noncondensable-gas removal performance, emissions limits, availability and reliability guarantees, and warranty terms with performance-liquidated damages.

This approach gives suppliers room to optimize their proprietary designs while holding them accountable for plant-level results. It also makes it easier to compare bids from different suppliers because each proposal is evaluated against the same performance requirements.

Balance standardization with site adaptation

Standardized ORC modules can reduce engineering time, simplify spare-parts inventories, and improve delivery certainty. Turboden’s framework agreement with Fervo Energy covers ORC units for up to 35 standardized 50 MW GeoBlocks, totaling 1,750 MW.

However, standardization should not override site-specific requirements. Brine chemistry, gas content, seismic design, grid connection, water availability, and permitting constraints may require customized separators, materials, controls, and cooling arrangements.

Plan for lifecycle cost

The lowest-capital-cost equipment package is not always the lowest-cost option over 25 to 30 years. Buyers should compare capital expenditure, energy efficiency and net output, maintenance labor and parts, planned outage frequency, corrosion and scaling mitigation, spare-parts lead time, water consumption, emissions treatment, digital monitoring and remote support, and contractual performance guarantees.

A slightly more expensive pump, seal, or heat exchanger may be justified if it reduces unplanned outages, extends maintenance intervals, or improves plant availability. In a geothermal plant, even a small improvement in availability can produce substantial additional revenue over the life of the asset.

Common procurement mistakes

One common mistake is buying turbines before confirming reservoir deliverability and steam or brine chemistry. Another is underestimating noncondensable-gas removal requirements. Buyers may also select heat exchangers without an adequate fouling and scaling allowance, or specify pumps without accounting for variable resource conditions.

Other frequent errors include ignoring spare-parts lead times for long-lead rotating equipment, treating the cooling system as an afterthought rather than a core performance driver, failing to align electrical, control, and protection systems with grid-code requirements, and comparing supplier bids without normalizing scope, guarantees, spares, and commissioning obligations.

Future equipment trends

Geothermal equipment is evolving toward modularization, digitalization, and broader resource applicability. ORC technology is expanding the addressable resource base because it can recover power from lower-temperature and waste-heat streams. Turboden positions its ORC systems for low-to-medium-temperature geothermal resources and next-generation geothermal projects, including enhanced geothermal systems.

At the same time, enhanced geothermal systems are increasing demand for scalable standardized power blocks. Fervo Energy and Turboden announced a framework agreement for ORC turbines covering up to 35 GeoBlocks and 1,750 MW of capacity, signaling growing interest in repeatable, factory-oriented geothermal equipment supply.

For equipment manufacturers, the commercial opportunity lies in offering reliable packages that reduce development risk. These include corrosion-resistant pumps, scalable ORC modules, high-efficiency heat exchangers, compact air-cooled condensers, and digital condition-monitoring systems.

Key takeaway

The best geothermal equipment strategy matches the technology to the resource, then procures for lifecycle performance rather than lowest upfront price. Turbines and ORC expanders determine conversion efficiency; pumps determine fluid reliability; heat exchangers and condensers determine thermal performance; and integrated suppliers can reduce interface risk across the plant.

For developers and EPC teams, the strongest procurement packages are those that combine credible performance guarantees, geothermal-specific materials and sealing solutions, modular delivery options, and long-term service support. A well-specified equipment package can improve plant availability, reduce operating risk, and help a geothermal project deliver dependable clean power for decades.