Techno-Economic Assessment of Geothermal Energy Resource in the Jharia Coal Field of India

The Jharia Coalfield (JCF), the magnificent pocket of coking coal in the southern part of the Dhanbad district of Jharkhand India, has always remained at the peak of attention for the technological challenges that occurred during the mining of coal. The JCF is also the most critically highlighted coalfield as it is the only known depository of prime coking coal in India which is infamous for its extensive coal fires ignited mainly due to its dynamic spontaneous combustion nature. Earlier studies reported significant anomalous temperature variations in the range of 160-200⁰C along subsurface cracks and vents; also the geothermal gradient is locally high in  the basin to be around 40-45⁰C/km. The implementation of geothermal heat extraction technologies to utilise the wasted heat underneath would require a comprehensive understanding and estimation of the techno-economics of various operational and maintenance costs. The economic assessment for a 5 MW geothermal plant revealed an initial investment cost of 12.02 (MM$) and 8.05 (MM$) and NPV to vary between 27.08 (MM$) to 31.04 (MM$)  respectively for the source temperature of 100⁰C and 150⁰C in the burning JCF basin.