New Running Strategies of a STIG Power Plant for District Heating

We describe the running plan of a 5.5-MWe-STIG-plant. Located in a medium-sized town in the centre of Italy, the plant both produces electric power and partially satisfies the thermal load of a nearby city district. An account of the Italian energy market is provided and the impact of recent legislation on plant operation is analysed. The liberalization of the Italian energy market in 1999 has significantly affected the technical and economic scenario for both existing and future power plants. As an example, we analyse the effects of liberalization on the overall performances of the plant described herein as well as the main changes in its running-strategies. A better economic result is shown to be possible in the new scenario mainly thanks to plant flexibility when operating as CHP (Combined Heat and Power) unit. The pursuit of optimum economic performance however prevents the plant from working at its best energetic efficiency.