A Comparative Study of Geothermal Potential of the East and West-Coast Hot Springs, India

Geothermal energy is an important source that has the potential to contribute to the energy needs of society. In this study, we try to understand the hydro-geological characteristics of the hot springs located in the two important coastal terrains of India. i.e., East Coast and West Coast. Our findings indicate that the west coast springs are dominated by Na-Cl, Ca-SO₄, and Na-HCO₃ water types, indicating that seawater intrusion through deep penetrating faults and fractures may have an impact. The majority of the east coast's hot springs which are located in Odisha have Na-Cl, and Ca-HCO₃ water types and a short residence period. According to our findings, hot springs on the west coast have a higher potential compared to Odisha for producing geothermal energy. We find that hot springs on the West Coast are mostly composed of Na-Cl, Ca-SO₄, and Na-HCO₃ water and that they may be influenced by seawater intrusion. Hot springs on the east coast, particularly in Odisha, have Na-Cl and Ca-HCO₃ water and have a short residence period. Some ionic concentrations have a strong correlation, indicating that seawater-rock interactions were dominant in the West Coast and some springs of Odisha thermal springs. The reservoir temperatures for the west and east coast springs, using the saturation-index method is found to be 120±5°C and 110±5°C. The reservoir depths and geothermal fluid circulation depths are estimated to be 1.71 ±0.17km and 1.37±0.32km, respectively. The control of water circulation in hot-spring systems is largely dependent on faults and subsurface high heat flow.  In comparison to Odisha, the West Coast thermal water is heated at a greater depth (1.71±0.17km at 120±5°C); circulation and mixing of thermal water via deeply connected faults and NNW-SSE lineaments. The West Coast springs' reservoir and geothermal fluid circulation depths are greater than those of Odisha, indicating greater circulation.