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Field testing of ORC processes

EnEff:Wärme - Forschung für energieeffiziente Wärme- und Kältenetze
Zu sehen ist ein Verdampfer ORC-Prozess mit Abgaswärmezufuhr aus einem Gasmotor

ORC process evaporator with input of exhaust gas heat from a gas motor

© Fraunhofer UMSICHT

Settlement summary

Project status Projektstatus: Phase 4Evaluation
Location Development and planning in Oberhausen and Ingelheim; realisation at 6 CHP plant sites of project partners
Project plan Continuation of process development; realisation of 5 more ORC field systems at 3 sites; subsequent monitoring with analysis of results in service
Developer, organizer Fraunhofer UMSICHT, Oberhausen; Cyplan Ltd., Ingelheim
Project themes

Project description

The Organic Rankine Cycle (ORC) is an operating process for steam turbines that uses a working medium other than water vapour. An organic substance with a low boiling point is used in place of water as the working fluid. This process is mainly used where the temperature difference available between the heat source and the heat sink is too low to operate a turbine driven by water vapour. With ORC systems, it is possible to convert thermal energy from small-scale sources – e.g. waste heat, geothermal energy, biomass or solar thermal sources – into electrical energy in an economically viable manner.
Waste heat from CHP plants is released to the surroundings without being harnessed at many CHP plant sites in the renewable energy sector (biogas, vegetable oil, sewage gas, landfill gas, coalmine gas). ORC processes can be used to convert previously unharnessed waste heat into valuable effective energy in the form of electricity. The ORC can also be operated in cogeneration mode. The goal of this project is to use ORC processes to generate between 20 and 120 kWel of additional electricity from the heat contained in exhaust gases and cooling water from motor CHP plants and, in doing so, to improve the energy balance of these motors.


With their relatively short payback times of between 3 and 6 years, standardised, small-scale ORC processes – implemented in the form of ORC modules – are commercially viable for CHP plant operators if the production costs are low enough. Operators can invest directly in these systems, which are also attractive for energy service companies in the context of waste heat contracting agreements. All of the additional electricity generated as compared to the initial state without generation using waste heat can be treated as a gain from a climate protection viewpoint.


The eight ORC field systems for power generation using waste heat that were installed at six sites as part of this project will be subject to subsequent operation monitoring for a period of five years.

Energy characteristics

before potential after unit
Electrical efficiency of motor 40,00   45,00 %

Cost-effectiveness characteristics

before after unit
Total project costs 4,50   Mio. Euro
Planning costs 1,40   Mio. Euro
Annual electricity credit   1.500,00 Euro/kWel,ORC

Sustainability characteristics

before after unit
CO2 emissions of pilot systems   2.800,00 t/a
Primary energy reduction costs for pilot systems (after taking all development costs into account)   5,00 Cent/kWhel
Primary energy reduction costs in commercial operation (estimate)   2,50 Cent/kWhel
  • Fraunhofer UMSICHT press release dated 21 April 2008 concerning the presentation of an ORC pilot system at HANNOVER MESSE

Additional information:

Research, project management, planning, evaluation
Fraunhofer-Institut für Umwelt-, Sicherheits- und Energietechnik UMSICHT
Planning, marketing
Dürr Cyplan Ltd.
Operator, energy provider
EnviTec Biogas AG
Operator, energy provider
Entsorgungsgesellschaft Steinfurt mbH (EGST)
Operator, energy provider
ENARO Quarnbek GmbH
Rhein-Main Deponienachsorge GmbH
  • Zu sehen ist das Prozessprinzip des ORC-Prozesses
  • Dargestellt werden die Abwärmequellen eines BHKW-Motors
  • Gezeigt wird das Hochtemperatur-ORC-Modul A-100 HT
  • Gezeigt wird die isometrische Darstellung des ORC-Moduls A-100 HT
  • Zu sehen ist die Montage des Turbogenerators nach Anlieferung des ORC-Moduls
  • Zu sehen ist das Abladen des vormontierten ORC-Moduls am BHKW-Standort
  • Zu sehen ist eine Infrarotaufnahme des Turbogenerators im ungedämmten Betrieb