Operation Economy of Chp Plants Using Forest Biomass and Peat

In Finland most of the combined heat and power (CHP) plants are based on fluidized bed combustion and are co-combusting different types of woody biomass with peat. Due to the CO2 emission reduction targets and subsequent renewable energy support mechanisms, the share of biomass has been increasing. Biomass utilization can increase plant's operational costs through higher fuel costs and negative effects on efficiency and availability of the boiler and increased maintenance work. The economic feasibility of biomass utilization is then dependent on whether the policy support measures make up for the additional costs. An interactive toolkit was developed to help to understand the relevance of various factors affecting the operation economics of a multifuel CHP plant and to study the respective competitiveness of peat and different types of forest biomass. In the fictional case example co-combustion of forest biomass and peat was found to be more feasible option than using either peat or forest biomass alone in the current market situation. Co-combustion provides synergy effects which decrease the O&M costs. The current low price of CO2 emission allowances makes biomass utilization dependent on the subsidies. The competitiveness between biomass and peat is also naturally strongly affected by the relative fuel price developments.