A review on multiple approaches for geothermal exploration in India and the way forward

India's surging power demand vis-à-vis the sustainability efforts to address climate concerns has already influenced a policy shift toward renewable energy resources. Among these, geothermal energy emerges as a promising green alternative. The country’s geothermal potential is evidenced by the presence of 381 geysers and hot springs, with surface to near-surface temperatures ranging from 97 °C to 150 °C. Although foundational in nature, the research has dominantly been carried out for geochemical characterization and regional-scale heat mapping, whereas the geothermal development in India is still in its early stages. While complex geology is a common feature in many geothermal regions, the diverse tectonic settings across India's geothermal provinces present additional challenges for subsurface characterization. To manage the high cost of exploration in these hilly, complex terrains, the efforts need to be complemented by integrating surface and subsurface geophysical methods. This article conducted an up-to-date, extensive review of prior studies in India, including the latest updates on policy development to promote geothermal exploration and its commercialization. A bibliometric analysis was conducted to understand the scientific articles' contributions to Indian geothermal exploration and development. Considering the latest data, the authors present a new geothermal province map of India and a heat flow map of Peninsular India to support their arguments. This article serves as a navigator on geothermal exploration in India for researchers, policymakers, and industry. This review emphasizes the necessity of integrating remote sensing, geophysics, geology, and geochemistry to optimize geothermal exploration and development in India. It also highlights the need for a centralized geothermal resource management system to stimulate investment and its sustenance.