IN Brief:
- The 33MWe Mehmet Ege geothermal project is planned in Germencik, Aydın, using a resource at approximately 160°C.
- Exergy will supply an organic Rankine cycle system with two radial outflow turbines, including a 29MW unit.
- Manufacturing is planned in Türkiye, with commissioning targeted for the second half of 2027.
Exergy International has secured a contract to supply a 33MWe organic Rankine cycle power plant for Maren Maraş Elektrik Üretim in Türkiye, including a 29MW radial outflow turbine described as the largest unit of its type the company has supplied. The Mehmet Ege project is planned for the Germencik district of Aydın province and will use heat from a geothermal resource reported at approximately 160°C. Exergy is responsible for engineering, design, manufacture and delivery of the generating technology, together with technical advice during installation and commissioning. The plant is targeted to enter operation in the second half of 2027.
Mehmet Ege will have two turbines based on Exergy’s radial outflow design, including a machine rated at 29MW. That turbine is a component of the 33MWe station rather than a separate 29MW project. The supplier has not published the second turbine’s rating or a detailed allocation of gross generation and auxiliary electricity consumption. Engineers will need to integrate both turbine-generator trains with the heat-exchange system and the plant’s electrical export arrangements before the overall output can be demonstrated.
Organic Rankine cycle (ORC) technology allows electricity to be generated from heat sources that are less suited to a conventional high-temperature steam turbine arrangement. Geothermal fluid transfers its thermal energy through heat exchangers to a separate working fluid with suitable boiling characteristics. That fluid is vaporised, expands through a turbine coupled to a generator, then is cooled and returned to the cycle. The working-fluid circuit is separate from the geothermal resource, and electrical output depends on more than the temperature of the geothermal fluid alone.
The reported geothermal resource temperature of approximately 160°C establishes one of the parameters used to design the plant’s heat exchangers and working-fluid cycle. The amount of usable heat also depends on the flow rate, the temperature at which the geothermal fluid can be reinjected, and losses through the equipment. Cooling conditions influence the pressure at which the working fluid condenses, affecting the energy available for conversion into electricity. Exergy has supplied a capacity target but no verified forecast of annual output or net thermal efficiency for Mehmet Ege.
Exergy’s radial outflow turbine directs the expanding working fluid outwards through the rotor stages, unlike an axial-flow design in which the main flow progresses along the machine’s shaft. The 29MW unit is the largest radial outflow turbine the supplier has yet committed to deliver. Its scale places demands on rotor dynamics, bearings, sealing, the generator interface and equipment testing. The manufacturer has not specified the working fluid or contractual performance guarantees, so the engineering comparison can be made at the level of turbine configuration and rating rather than assumed efficiency gains.
The contract also places manufacturing work within Türkiye. Exergy says turbines, generators and auxiliary equipment will be manufactured and assembled at its Turkish operation, with the supply intended to meet the requirements for Made in Türkiye certification. Local production is therefore a defined element of this equipment order, rather than an assumption about where the plant’s components will originate. Transport to site, mechanical installation, electrical interconnection and acceptance testing remain subsequent stages before the generating unit can enter service.
The installation is one part of a larger development planned by Maren in the Germencik district. Three proposed 33MWe geothermal stations would together provide 99MWe under the J-552 geothermal resource operating licence. Exergy’s new equipment order applies specifically to Mehmet Ege; procurement for the other two proposed plants is not established by this contract. Construction sequencing for the wider programme will also depend on developing the geothermal wells, collection systems and electrical connections serving each unit.
Exergy and Maren have worked together on earlier geothermal developments in Aydın. Exergy delivered the 33MWe Emir and 13MWe Nezihe Beren 2 geothermal plants in Aydın under an earlier agreement, and subsequently confirmed that they had passed the relevant acceptance processes in 2025. Exergy identifies Mehmet Ege as its fourth repeat order from Maren, bringing the total generating capacity covered by their contracts to 129MWe. Including a separate 12MW installation supplied to Kiper Elektrik Üretim, another company within the Kipaş group, it puts the wider group relationship at 141MWe.
The two earlier plants supplied to Maren provide a reference for Exergy’s technology, while Mehmet Ege still requires manufacture, delivery, installation and commissioning. The ORC equipment must be integrated with geothermal fluid handling, heat exchangers, condensers, electrical protection and the site’s grid connection. Factory tests can establish component performance, but the completed installation also needs to demonstrate stable operation with the resource and cooling systems available at Germencik. Exergy has identified the second half of 2027 as the target for the plant to enter operation.
The signed order adds a larger individual turbine to Exergy’s geothermal portfolio and supports one stage of Maren’s proposed 99MWe development. Equipment production in Türkiye is expected to precede delivery and integration of the generating systems at Mehmet Ege. The principal remaining milestones are manufacturing completion, on-site assembly, electrical testing and grid-connected operation. Those will establish whether the planned 33MWe station has progressed from procurement to actual generating capacity.
