Competitiveness of small power plants using ambient pressure, air-blown gasifiers. Final report. [Seven 50 MW designs using fuel gas, fuel oil, natural gas and coal]

Small power plants have become more attractive to utilities recently for a variety of reasons, including the desire to minimize new plant investment and to tailor increases in generation base to smaller annual load growths. The study presented herein is an analysis and comparison of seven different 50 MW commercially available power plants designs, including four utilizing ambient pressure, air-blown, fixed-bed coal gasifiers for fuel supply. Plant designs, capital costs, and busbar electricity costs for each plant are presented. The results of the study indicate that nominal 50 MW coal gasification based power plants, when using commercially available, ambient pressure, air-blown, fixed-bed gasifiers, are not competitive with conventional coal-fired steam plants or combined cycle plants fueled with fuel oil or natural gas. Capital costs, heat rates, and operating costs are higher for the coal gasification based plants. This leads to costs-of-electricity for gasification based plants that range from 18 to 59% higher than costs of electricity produced in conventional plants. The two major influences leading to high costs of the gasification based plants are the small size of a gasification train (about 5 MW) and the need to compress the ambient pressure gas to required combustion pressure. 47 figs., 89more » tabs.« less