The Central Electricity Authority (CEA) in India has finalised a detailed Master Plan for Evacuation of Power from Hydroelectric Plants in the Brahmaputra Basin, setting out the framework for transmitting up to 76GW of hydroelectric and pumped storage capacity from India’s most resource-rich river system.

The plan covers 64.9GW of conventional hydro potential (projects above 25MW) and an additional 11.1GW from proposed pumped storage plants (PSPs). Together, these projects span 12 sub-basins, including the Siang, Subansiri, Dibang, Lohit, and Barak systems across Arunachal Pradesh, Assam, Sikkim, Meghalaya, Mizoram, Manipur, Nagaland, and West Bengal.

The transmission development is divided into two timeframes – up to 2035 and beyond 2035 – to match the expected commissioning schedules of hydro projects.

By 2035, the plan calls for:

  • 9,922 circuit kilometers (ckm) of transmission lines, including 6,000 ckm of HVDC corridors
  • 41,760 MVA of transformation capacity, including 12 GW of HVDC transfer capability

Beyond 2035, an additional:

  • 21,475 ckm of lines (15,000 ckm HVDC)
  • 68,175 MVA of transformation capacity (30 GW HVDC)

In total, the plan envisions 31,397 ckm of new transmission infrastructure and 109,935 MVA/MW of transformation and DC transfer capacity.

Arunachal Pradesh dominates the hydropower profile, accounting for more than 80% of the total installed potential, with Siang (18.7GW), Subansiri (12.3GW), and Dibang (8.8GW) as key contributors. Other significant basins include Lohit (6.8GW), Kameng (3.3GW), and Barak (4.6GW).

The pumped storage component (11.1GW) is distributed mainly in the Barak and Kalang (Kopili) sub-basins. Notable schemes include:

  • Panyor PSP (660MW) – Arunachal Pradesh
  • Wah Umiam PSP (800MW) – Meghalaya
  • Longtharai PSP (800MW) – Tripura
  • Ouguri PSP (900MW) and Tharakunji PSP (900MW) – Assam
  • Daizo Lui PSP (2,400MW) and Tuiphai Lui PSP (1,650MW) – Mizoram

The master plan identifies 40 major pooling stations and HVDC terminals, including key nodes at Namsai, Roing, Niglok, Gogamukh, Rowta, Silapathar, and Melriat-II. HVDC corridors will form the backbone for bulk power transfer from the North Eastern Region to the national grid.

The total estimated investment for transmission infrastructure is approximately ₹6.43 lakh crore, including ₹1.91 lakh crore for the pre-2035 phase and ₹4.52 lakh crore for works beyond 2035.

CEA stated that implementation will proceed in stages, guided by project readiness and applications received by designated nodal agencies. Transmission elements will adhere to the CEA Manual on Transmission Planning Criteria, and future adjustments – such as higher-capacity HVDC or hybrid AC-DC systems – will be considered depending on technology and system requirements.

The report highlights that the plan is intended to give developers and state utilities early visibility of transmission corridors, enabling coordinated scheduling of generation and grid integration. It is also expected to strengthen inter-regional connectivity and improve reliability of renewable energy supply from the North Eastern Region.

“The Brahmaputra basin represents the single largest untapped hydroelectric zone in the country,” CEA officials noted. “This master plan ensures that transmission readiness will not be a bottleneck as projects move forward.”