Need for an investment subsidy for waste cogeneration plants

Building of new waste-fueled CHPs has been economically evaluated. Total investment cost have been calculated for plants of three different sizes, 2x15, 2x25, and 2x50 MW thermal power, respectively. The calculations show that the small plants have poor and the large plants mediocre profitability. Better economy can be achieved for the large plants if a higher steam quality than normal is used (120 bar, 540 degree C instead of 40 bar, 400 degree C). The conclusions are that investment subsidies are necessary for building these plants, in particular the small ones. Subsidy levels are estimated according to two principles: Pay-back no later than eight years after commissioning, or covering of deficits until revenues surpasses capital costs. Use of biofuels to level the fluctuations in waste flow, and thus make more efficient use of the plant, can also help the economy of the plant. (8 figs., 15 tabs.)