The ORC technology is particularly suitable for the exploitation of medium-to-low enthalpy sources. It is a cost-effective solution with power outputs reaching up to 40 MWe per single generator for sources with water temperature of 100°C to 200°C or higher.




MWe total


first plant delivered

*3 plants are under construction

Binary geothermal ORC plant with closed loop

Example of geothermal plant with a Turboden ORC system


Heat from the earth can be used as a base load energy source. Geothermal heat is inexhaustible and renewable. It can be found in many regions of the world, especially at tectonic plate boundaries or at places where the crust is thin enough to let the heat through. The most common way of capturing the energy from geothermal resources is to tap into naturally occurring hydrothermal convection systems, where cooler water seeps into earth’s crust and is heated up within a reservoir of water and/or steam.

  • Average plant availability: 99% on all the fleet in operation
  • Complete in-house design (above ground process and technology


Binary power plants do not directly use geothermal fluid for electric power generation (as in the  conventional flash steam turbines), but a secondary fluid is heated up and vaporized by means of heat exchange with the geothermal fluid, in order to drive a turbine and produce electricity. The heat that is not converted into electricity can be delivered to a thermal user or dissipated by means of a suitable cooling system. In a binary plant the geothermal fluid is circulated within a closed loop of piping (from the reservoir to the reinjection well) without passing through the turbine, thus virtually zero emissions to the atmosphere is achievable. Binary plants require low and easy maintenance and are suitable for the electrification of remote areas or island with unstable grid. The thermodynamic process used by Turboden in the binary power plant is the Organic Rankine Cycle.


By selecting a “lower boiling fluid” rather than water it is possible to efficiently exploit also heat sources within the range of 100 °C to 200 °C. Thermodynamic cycle configurations, which are inaccessible in the state diagram of water, can be obtained with organic fluids having different parameters, and with high efficiency.


  • Geothermal fluid remains isolated from the environment and the turbine
  • Dry expansion: no fluid condensation in the turbine (unlike in the geothermal flash steam turbines), with no erosion
  • High molecular mass fluid: low peripheral speed are required for the turbine, with low mechanical stress
  • Low enthalpy drop across the turbine: low number of turbine stages, thus turbine size and cost is smaller
  • Small expansion ratio across the turbine: small blades size increase during expansion compared to water steam


  • Capacity: Solutions up to 40 MW per single generator
  • Temperature range: from 100 °C to more than 200 °C
  • Working fluids: Hydrocarbons, HFCs, HFOs
  • Thermodynamic process and control philosophy designed by Turboden
  • Turbine type: Axial multi stage, Turboden proprietary design
  • Key equipment designed in house (e.g. Air Cooled Condenser and Heat Exchangers)
  • Operation in remote areas: Off grid capability (island mode) and active grid balancing
  • Combined heat and power solutions


ORC size location customer status notes
1 MWe Altheim, Austria Marktgemeinde Altheim GmbH In operation since 2001 Heat & Power
5 MWe Sauerlach (Munich), Germany SWM - StadtWerke München In operation since 2013 Heat & Power
0.4 MWe Livorno, Italy Enel In operation since 2012 Supercritical prototype
5.6 MWe Duerrnhaar (Munich), Germany SWM - StadtWerke München In operation since 2012 Power only
5.6 MWe Kirchstockach (Munich), Germany SWM - StadtWerke München In operation since 2013 Power only
4.1 MWe Traunreut, Germany Geothermische Kraftwerksgesellschaft Traunreut GmbH In operation since 2015 Heat & Power
6 MWe Japan Mitsubishi Heavy Industries In operation since 2015 Power only
3 MWe Afyonkarahisar, Turkey Afjet (Afyon Jeotermal) In operation since 2016 Power only
1.7 MWe Soultz-sous-Forêts, France GEIE - Exploitation Minière de la Chaleur In operation since 2016 Power only
16 MWe Velika Ciglena, Bjelovar, Croatia MB Holding Under construction Power only
3.4 MWe Holzkirchen, Germany Geothermie Holzkirchen GmbH Under construction Heat & Power
14 MWe Animas, United States of America Cyrq Energy Inc. Under construction Power only

Geothermal case histories