Life cycle-based environmental evaluation of indian hydropower plants: Insights from a multi-regional input-output analysis

Hydropower constitutes a significant portion of India's total installed power generation capacity, offering critical advantages such as peak load management, grid stability, and multipurpose water resource utilization. While its benefits are well recognized, hydropower development, particularly large-scale projects, has raised considerable environmental concerns over recent decades. In response, small hydropower (SHP) projects have emerged as decentralized, cleaner alternatives with relatively lower ecological impacts. However, a comprehensive environmental evaluation is essential to understand the trade-offs involved in different hydropower configurations. This present study deals with a comparative environmental assessment of a large reservoir-based hydropower project and a small dam-toe SHP plant in India using a Multi-Regional Input-Output (MRIO) based Life Cycle Assessment (LCA) approach. The methodology captures upstream and downstream environmental impacts by integrating global trade flows and regional economic interactions, offering a systems-level perspective. Environmental impacts are assessed using the ReCiPe method at both mid-point and end-point levels. Findings indicate that the environmental impacts per megawatt-hour (MWh) of electricity generation are broadly comparable between the large and small hydropower systems. Across both cases, the construction phase emerges as the dominant contributor to environmental burdens, highlighting the significance of materials and supply chain processes. Furthermore, the normalized end-point impact results suggest that dam-toe SHP plants may exhibit higher per-unit environmental intensity due to their lower energy output, despite their smaller scale. These insights emphasize the need for life cycle-based planning in hydropower development to balance energy generation with environmental sustainability, particularly in the context of India's growing demand for renewable energy.