Description of the ORC technology for biomass Combined Heat and Power plants as well as further possibilities for process integration: The ORC technology is based on a long term development with the aim to efficiently use solar energy, geothermal energy as well as energy from biomass in decentralised units. The principle of electricity generation by means of an ORC process corresponds to the conventional Rankine process. The substantial difference is that an organic working medium (hydrocarbons such as iso-pentane, iso-octane, toluene or silicon oil) with favourable thermodynamic properties at lower temperatures and pressures is used instead of water - hence the name Organic Rankine Cycle (ORC). The right choice of the organic working medium used is very important for an optimised operation of the ORC process. Considering the framework conditions given for biomass Combined Heat and Power applications (CHP plants), silicon oil is the most appropriate working fluid.