Evaluation of Electricity Generation From Underground Coal Fires and Waste Banks

A temperature response factors model of vertical thermal energy extraction boreholes is presented to evaluate electricity generation from underground coal fires and waste banks. Sensitivity and life-cycle cost analyses are conducted to assess the impact of system parameters on the production of 1 MW of electrical power using a theoretical binary-cycle power plant. Sensitivity analyses indicate that the average underground temperature has the greatest impact on the exiting fluid temperatures from the ground followed by fluid flow rate and ground thermal conductivity. System simulations show that a binary-cycle power plant may be economically feasible at ground temperatures as low as 190°C.