To increase the power output of the plant and to become more independent of permanent heat sales, the plant is also equipped with an Organic Rankine Cycle (ORC) module. A thermal-oil circuit transports heat from the producer gas cooler, the flue gas cooler and the engine exhaust cooler to the ORC module at atmospheric pressure. The ORC module is similar to a conventional steam-turbine-cycle, where instead of water an organic fluid is used. This gives more flexibility in choosing pressure and temperature levels and eliminates the need for superheating the steam.