The expansion of India’s transmission system is essential for meeting the country’s growing electricity demand and supporting the integration of renewable energy sources. A robust transmission infrastructure is essential for efficiently transmitting power across vast distances, maintaining grid stability and ensuring uninterrupted electricity supply.
In October 2024, the Central Electricity Authority released the National Electricity Plan – Transmission, outlining the transmission network requirements up to 2031-32. The plan aligns with the revised (draft) Electric Power Survey (EPS), which projects a peak demand of 296 GW by 2026-27 and 388 GW by 2031-32. As per the plan, during 2022-27 period, 114,687 ckt km of transmission lines and 776,330 MVA of transformation capacity will be added at an investment of Rs 4,252.22 billion. In the subsequent period, 2027-32, the addition of 76,787 ckt km of transmission lines and 497,855 MVA of transformation capacity is expected at an investment of Rs 4,909.2 billion.
Review of transmission system augmentation during 2017-22
During the period from 2017 to 2022, 104,400 ckt km of transmission lines and 327,889 MVA of transformation capacity at 220 kV and above voltage levels were planned for installation. Of this, 88,865 ckt km of transmission lines were completed, achieving 85 per cent of the target, while 349,685 MVA of transformation capacity was added, exceeding the target at 107 per cent. Additionally, the planned 14,000 MW of high voltage direct current (HVDC) bipole capacity was successfully added during the period.
Notably, there has been significant growth at higher voltage levels, particularly 400 kV and 765 kV, reflecting the need for a robust transmission network to transport bulk power over long distances while optimising right of way (RoW), minimising losses and enhancing grid reliability. However, some planned transmission projects faced delays due to various challenges, including RoW issues, delays in obtaining forest clearances, contractual complications, land acquisition delays for substations and disruptions caused by the Covid-19 pandemic. On a positive note, several transmission systems not initially included in the targets were commissioned during the 2017-22 period.
Transmission system planned for 2022-27
The revised draft of the 20th EPS reports a peak demand forecast of 296 GW for 2026-27. The transmission requirements are assessed based on the current and planned intra-state and interstate systems, including cross-border links. To ensure effective load generation balance, nine scenarios are analysed, focusing on evening peak, night off-peak and afternoon high solar generation during February, June and August. For transmission system planning, the total installed electricity generation capacity is projected at 669 GW by 2026-27.
Network additions: Based on the anticipated increase in generation capacity and projected electricity demand, the plan estimates the addition of 114,687 ckt km of transmission lines and 776,330 MVA of transformation capacity at 220 kV and above voltage levels during the 2022-27 period. In addition, 1,000 MW of high HVDC bipole capacity is expected to be added during this period. During 2024-25, 16,667 ckt km of transmission lines and 116,490 MVA of transformation capacity are expected to be added. Overall, at the end of 2027, the total length of transmission lines will reach 571,403 ckt km, while the transformation capacity of substations (220 kV and above) will increase to 1,847,280 MVA. Furthermore, the total HVDC bipole capacity, including back-to-back systems, will increase to 34,500 MW.
The planned addition of interregional transmission capacity during the 2022-27 is 30,690 MW. This expansion will increase the total interregional transmission capacity from 112,250 MW in 2021-22 to 142,940 MW by the end of 2026-27. As of March 31, 2024, 6,490 MW of interregional capacity has been commissioned. Currently, 7,400 MW is under construction, while another 8,400 MW is in the bidding phase. As of March 31, 2024, the total interregional transmission capacity stood at 118,740 MW.
Cross-border power transfer: At present, approximately 4,100 MW of power is being exchanged through cross-border links, with projections indicating an increase to around 7,000 MW by the end of 2026-27. Discussions regarding the interconnection between India and Sri Lanka are currently at advanced stages. In addition, under the One Sun, One World, One Grid initiative, plans are under way to connect the Indian electricity grid with countries such as Singapore, the UAE and Saudi Arabia.
Estimated cost: An estimated expenditure of Rs 4,252.22 billion is required during 2022-27 to implement the additional transmission system, covering transmission lines, substations and reactive compensation, among other components. The estimated cost for the interstate transmission system (ISTS) is Rs 2,691.5 billion, while the estimated cost for the intra-state transmission system is Rs 1,560.72 billion.
Perspective transmission plan for the period 2027-32
The transmission plan for 2027-32 is designed to accommodate a peak electricity demand of 388 GW by 2031-32, as indicated in the revised (draft) 20th EPS. It estimates a total installed generation capacity of about 997 GW, incorporating renewable energy zones and additional coal and pumped storage capacity.
Network additions: Considering the planned generation capacity additions and projected electricity demand, 76,787 ckt km of transmission lines and 497,855 MVA of transformation capacity are expected to be added during 2027-32. Additionally, 32,250 MW of HVDC bipole capacity is expected to be added during the period. By the end of 2031-32, the total transmission line length is estimated to reach 648,190 ckt km, with a transformation capacity of 2,345,135 MVA. Furthermore, HVDC bipole capacity, including back-to-back systems, is expected to increase to 66,750 MW by the end of 2031-32. Several interregional transmission corridors are planned for the 2027-32 period, with 24,600 MW of interregional transmission capacity expected to be added. This expansion will increase the total interregional transmission capacity to approximately 167,540 MW by the end of 2031-32.
Transmission system for delivery of power to green hydrogen/green ammonia manufacturing hubs: As per initial estimates by the Ministry of New and Renewable Energy (MNRE), additional electricity demand from green hydrogen/green ammonia production is projected to reach 70.5 GW by 2031-32. While the MNRE is currently reassessing this demand, the transmission system has been planned based on the initial estimates to ensure power delivery to all the green hydrogen/green ammonia manufacturing hubs. The planned transmission system will be implemented in a phased manner, in line with the development of green hydrogen/green ammonia manufacturing hubs.
Estimated cost: An estimated expenditure of Rs 4,909.2 billion is required to implement an additional transmission system at voltage levels of 220 kV and above during the 2027-32 period. This budget covers the construction of transmission lines, substations and reactive compensation systems. Of this, the cost for the ISTS is estimated at Rs 3,916.24 billion, while that for the intra-state transmission system is Rs 992.96 billion.
Private sector participation in transmission
Till March 31, 2024, 144 ISTS schemes have been identified for implementation through the tariff-based competitive bidding (TBCB) route. Of these, 106 ISTS transmission schemes have been awarded through TBCB and 38 projects are currently under bidding. Of the remaining four projects, one project has been cancelled by the Central Electricity Regulatory Commission, one project has been requested for closure by the transmission service provider and construction on the other two could not start due to litigation.
Out of the 106 transmission schemes awarded for implementation through the TBCB route, 53 schemes have already been commissioned and 49 are under implementation, entailing an estimated cost of Rs 663.95 billion. In addition, 38 ISTS schemes, valued at Rs 1,238.86 billion, were under bidding as of March 31, 2024. These entail 19,100 ckt km of transmission lines, including 5,500 ckt km of HVDC lines; 1,37,990 MVA of transformation capacity; and a 14,500 MW HVDC system.
Meanwhile, at the intra-state level, some states have initiated the competitive bidding process for the award of transmission schemes. So far, Uttar Pradesh, Rajasthan, Madhya Pradesh and Maharashtra have started implementing transmission projects through the TBCB route. A total of 22 intra-state transmission schemes in Uttar Pradesh, Rajasthan, Madhya Pradesh and Maharashtra have been completed under the TBCB route. One intra-state transmission scheme in Odisha is under bidding and will be awarded through the TBCB route. Besides, some intra–state transmission schemes are being planned to be implemented through the TBCB route by the Jammu & Kashmir and Rajasthan governments as well as by DVC.
To conclude, the intra-state-and interstate-level transmission networks are expected to undergo significant network expansion and strengthening in the coming years. However, to expedite the implementation and commissioning of transmission systems, there is a need to address issues pertaining to RoW constraints, lack of trained manpower and contractual disputes. By proactively addressing these challenges, the reliability and efficiency of the transmission network can be enhanced, supporting the country’s energy transition goals and ensuring reliable power supply.
Priyanka Kwatra
