Role of Geophysics in Investigations for Pump Storage Projects

Pumped storage projects (PSPs) have gained significant attention in India due to the country’s increasing energy demands and the need for sustainable energy storage solutions. These projects play a pivotal role in balancing the grid, especially with the integration of renewable energy sources. However, the successful implementation of PSPs requires a comprehensive understanding of the subsurface, which is where geophysics comes into play. Geophysics offers a suite of non-invasive methods to investigate the subsurface conditions, crucial for the design and safety of PSPs. In the Indian context, where diverse geological formations exist, geophysical investigations become even more pertinent. These investigations help in identifying potential sites for PSPs, assessing the geological and hydrogeological conditions, and ensuring the structural integrity of the proposed infrastructure.

In India, for PSP investigations, seismic refraction and electrical resistivity imaging are two of the most commonly deployed geophysical methods. Seismic refraction offers insights into subsurface structures, enabling the identification of fault lines, fractures, and other geological intricacies that can influence the safety and efficacy of storage reservoirs. Concurrently, electrical resistivity imaging, an advanced form of the traditional electrical resistivity method, is instrumental in delineating the groundwater table, lineaments etc. It also pinpoints areas susceptible to seepage, a critical factor in the design and construction of reservoirs. The combined deliverables of these techniques underscore their significance in ensuring the robustness and reliability of PSPs in the region. MASW (Multichannel Analysis of Surface Waves) and GPR (Ground-Penetrating Radar) also have potential to be utilized for geophysical investigations of PSP projects. MASW aids in determining the shear wave velocity of the subsurface, providing insights into the ground’s elastic properties and Vs30. On the other hand, GPR offers high-resolution imagery of the shallow subsurface, facilitating the identification of cavities, voids, and other anomalies that could jeopardize the project. Together, these methods furnish invaluable data about geological formations, playing a pivotal role in refining the design of the PSPs. Crosshole seismic tomography is another tool for PSP (Pumped Storage Projects) investigations. This advanced geophysical method involves generating seismic waves between boreholes to create detailed images of the subsurface. For PSPs, understanding the subsurface is paramount, as it directly impacts the safety and efficiency of the storage reservoirs. Crosshole seismic tomography provides high-resolution data on rock quality, fracture zones, and potential voids or anomalies. By offering a comprehensive view of the subsurface conditions, it aids in optimizing the design, construction, and operation of PSPs, ensuring their longevity and reliability. The geophysical investigations need to be complemented by geotechnical drilling and laboratory tests, ensuring a holistic understanding of the subsurface conditions. This integrated approach ensures that the design and construction of PSPs are based on sound scientific principles, minimizing risks, and optimizing performance.

This paper presents an in-depth analysis of the pivotal role geophysics holds in the investigations for pumped storage projects within the Indian context. Considering India’s varied geological landscape and the growing focus on integrating renewable energy sources, the significance of geophysical investigations is underscored. The paper delves into how these investigations are instrumental in guaranteeing the safety and optimal performance of PSPs. Furthermore, to provide a practical perspective, the paper will encompass several case studies, highlighting their contribution to India’s journey towards a sustainable energy future.