The objective of this study is to evaluate the performance of waste coal and biomass co-fired 100 MW power generation using a commercial software, i.e., STEAM-PRO. The selected feedstocks are anthracite waste coal and loblolly pine biomass. The performance of co-fired plant was analyzed at biomass and coal refuse cofiring ratios such as 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. The STEAM-PRO model was validated using literature data, and the major parameters were in the range of 5 to 6% while a few parameters were in the range of 11 to 13% which are within the acceptable range. As the biomass to waste coal ratio increased from 0:100 to 100:0, the gross power, net heat rate, auxiliary power, fuel flow rate, and CO2 emissions are decreased for both with and without carbon capture and storage (CCS) cases. The maximum net plant LHV efficiency of 37.11% was observed at co-firing ratio of 100:0, i.e., 100% biomass case. The addition of CCS has resulted into a significant reduction in net plant LHV efficiency. Although the addition of CCS reduced the net thermal efficiency, CO2 and SO2 emissions have been reduced significantly.