Optimization of the Operation Management of an Organic Rankine Cycle Fed by Biomass Serving a District Heating Grid

In these last years, many actions have been taken to decrease the consumption of fossil fuels and the impact on the environment of the human activity. Among these actions, a special attention is paid to the use of renewable energy sources to substitute the more traditional fossil fuels. This paper describes a new plant sited in Asiago (Italy). It is arranged by 2 boilers fed by the wastes from a sawmill: one of them directly supplies hot water to a district heating grid, while the other provides for the heat a cogenerative Organic Rankine Cycle (ORC). The ORC plant has a nominal electric power of 1.25 MW and can produce 5.3 MW of heat. The plant is connected to the electric grid. For different operation strategies, the results of the energy analysis as well as those of the economic one will be described. A special attention will be paid to the influence of the incentives on the results of the economic analysis. The emissions will be also evaluated and compared with those of the pre-existing solution, where each user produced heat by domestic boilers fed by natural gas or diesel oil.