Context:
• The Subansiri Lower Hydroelectric Project (2,000 MW), India’s largest hydropower venture, has entered its wet commissioning phase, marking a key milestone toward full operationalization.
• The project, developed by NHPC Ltd, is critical to India’s clean energy and self-reliance goals, though it has faced long-standing environmental and social challenges.
Key Highlights:
- Project Overview:
- Location: Gerukamukh on the Arunachal Pradesh–Assam border.
- Capacity: 2,000 MW (8 units × 250 MW each).
- Developer: NHPC Limited (National Hydroelectric Power Corporation).
- Initiation: Construction began in January 2005; suspended in 2011 following protests; resumed in October 2019.
- Status: First unit (250 MW) undergoing wet commissioning; four units ready for test runs.
- Technical Details:
- Wet commissioning involves testing turbine operation with water flow before power generation.
- Synchronization of two units will enable initial power generation.
- Full commissioning expected soon, marking a major milestone in India’s hydropower expansion.
- Environmental & Social Dimensions:
- The 2011 protests were driven by concerns over downstream impact on Assam’s ecology and livelihoods.
- Post-resumption, NHPC incorporated enhanced safety and flood-mitigation measures, and continuous environmental monitoring protocols.
Relevant Prelims Points:
• Subansiri Lower Hydroelectric Project:
- Located on the Subansiri River, a tributary of the Brahmaputra River.
- Joint boundary project between Arunachal Pradesh and Assam.
- Total installed capacity: 2,000 MW, India’s largest hydropower project to date.
- Executed by NHPC Ltd, India’s premier hydropower PSU under the Ministry of Power.
Relevant Mains Points:
• Significance:
- Boosts India’s renewable energy portfolio and contributes to energy diversification.
- Enhances grid stability through hydropower’s balancing role in renewable integration.
- Supports India’s Net Zero by 2070 and Atmanirbhar Urja Bharat goals.
- Challenges:
- Ecological sensitivity of the Eastern Himalayas; downstream flooding risk.
- Sedimentation and siltation issues affecting turbine longevity.
- Displacement and livelihood concerns for local communities.
- Way Forward:
- Strengthen basin-level environmental impact assessments for future hydro projects.
- Adopt modern dam safety technologies and real-time monitoring systems.
- Promote community engagement and benefit-sharing for local acceptance.
- Integrate hydropower with pumped storage systems to enhance flexibility and reliability.