Integrated Solar Geothermal Setup for Low Enthalpy Geothermal Reservoir

Abstract

There are many surface manifestations of geothermal energy with varying temperatures located in the state of Gujarat in India. However due to limited exploration survey of geothermal energy in the study area; the subsurface geology picture was unclear. Hence the location of geothermal systems which proves the existence of potential heat source was also unclear. The present researcher has tried to detail out the subsurface understanding using geophysical surveys such as seismic, gravity, magnetic, and electrical resistivity. The present study also tries to integrate the data obtained from all these geophysical methods and locate the zones of geothermal. Literature studies indicate that most of India’s geothermal resources fall under the category of medium-low enthalpy and hence underperform when harnessed for standalone power generation. Improvement of enthalpy of geothermal water is possible by hybridization with other renewable energy. Based on literature review a very interesting match was noticed between solar thermal and geothermal energy. Several plots are made between power generation and time over the last 16 months. After careful optimization of the orc pump frequency and temp difference between the heating and cooling side of the ORC, stability is achieved in the power output over a longer period of time. It is observed that the plateau period ranges between 19 and 25 kW for a time span of 6-7 hours. This is a remarkable achievement as far as a demonstration project is concerned which will act as a que to commercialization.