The estimated expenditure for implementing the additional transmission system (including transmission lines, substations, and reactive compensation) during 2022-27 is projected at ₹4.25 trillion (~$50.55 billion), according to the Volume II – Transmission of National Electricity Plan issued by the Central Electricity Authority (CEA).

Expanding India’s transmission system from 2022-27 will include the addition of 114,687 ckm of transmission lines and 776,330 MVA of transformation capacity at 220 kV and above. Additionally, 1,000 MW of High Voltage Direct Current (HVDC) bi-pole capacity is planned. These developments will bring the total transmission line length to 571,403 ckm, the transformation capacity to 18,47,280 MVA, and the HVDC bi-pole capacity to 34,500 MW by the end of 2027.

This expansion is driven by projected electricity demand and generation capacity additions outlined in the 20th Electric Power Survey (EPS) report. By 2026-27, the peak electricity demand is expected to reach 277 GW, for which an installed generation capacity of  609.6 GW is required.

Considering inputs from the Ministry of New and Renewable Energy (MNRE) and the Solar Energy Corporation of India (SECI), around 111 GW of wind and 208 GW of solar capacity is likely to be added by 2026-27, bringing the total estimated installed generation capacity to 669 GW by that time.

In 2022-23, 14,625 ckm of transmission lines and 75,902 MVA of transformation capacity were added, followed by 14,203 ckm of transmission lines and 70,728 MVA in 2023-24. The target for 2024-25 is 16,667 ckm of transmission lines and 1,16,490 MVA of transformation capacity.

Adequate reactive compensation in bus reactors, line reactors, and static compensators (STATCOMs) has been planned to provide reactive power support to the grid under steady-state and dynamic conditions. Upcoming substations, particularly those integrating renewable energy generation, will have space for future reactors and STATCOMs.

Substantial growth in interregional transmission capacity has ensured power can flow from surplus to deficit regions, optimizing the use of generation resources. By the end of 2021-22, the interregional transmission capacity stood at 112,250 MW. During 2022-27, an additional 30,690 MW of interregional transmission capacity is planned, which will increase the total capacity to 142,940 MW by 2026-27.

As of March 2024, 6,490 MW of inter-regional capacity had already been commissioned, with 7,400 MW under construction, 8,400 MW under bidding, and 8,400 MW planned for bidding and construction in 2024-25. By March 31, 2024, the total inter-regional transmission capacity was 118,740 MW.

Perspective Transmission Plan (2027-32)

The estimated expenditure for additional transmission systems during 2027-32 is projected to be ₹4.91 trillion (~$58.4 billion). These cost estimates will be revised as states and union territories continue firming up their intra-state transmission plans.

The peak electricity demand for 2031-32 is projected to be 366 GW, requiring an installed generation capacity of 900 GW.

The revised EPS report projects peak demand at 388 GW by 2031-32. Considering renewable potential zones and additional coal-based and pumped storage generation capacity, the installed generation capacity is expected to reach 997 GW by 2031-32.

For this period, 76,787 ckm of transmission lines and 4,97,855 MVA of transformation capacity at 220 kV and above will be added, bringing the total to 6,48,190 ckm and 23,45,135 MVA, respectively.

The HVDC bi-pole capacity will rise to 66,750 MW. The transmission system will also support 47.2 GW of battery energy storage systems, reducing the need for additional transmission infrastructure and improving system utilization.

Inter-regional transmission capacity is planned to increase by 24,600 MW during 2027-32, reaching 167,540 MW by 2031-32.

Transmission System for Green Hydrogen Hubs

Additional transmission systems will be developed for coastal areas in Gujarat, Odisha, West Bengal, Andhra Pradesh, Tamil Nadu, and Karnataka to support green hydrogen and green ammonia production. The estimated additional electricity demand for green hydrogen/ammonia production by 2031-32 is 70.5 GW, although MNRE is revising this figure. The transmission system for these hubs will be implemented in phases that align with establishing production facilities.

Last November, CEA began planning to install transmission infrastructure in consultation with the Central Transmission Utility to cater to the power demands of upcoming green hydrogen and green ammonia plants across seven coastal and three inland states.

Technology Upgradation

Several advanced technologies, including hybrid substations, digital substations, compact towers, extra-high-voltage cables, high-temperature low-sag conductors, UAV route surveys, and voltage-sourced converters, are being considered to optimize the transmission system’s development. These technologies will help enhance power flow, ensure efficient grid management, and address challenges like right-of-way limitations.

Transmission System Augmentation (2017-22)

During the period from 2017-22, the Indian government had planned to add 1,04,400 ckm (circuit kilometers) of transmission lines and 3,27,889 MVA of transformation capacity at voltage levels of 220 kV and above. By the end of the period, 88,865 ckm (85% of the target) of transmission lines and 3,49,685 MVA (107% of the target) of transformation capacity had been added. The planned 14,000 MW of HVDC bi-pole capacity was also completed during this time.

By March 31, 2022, the total length of transmission lines stood at 456,716 ckm, with a transformation capacity of 1,070,950 MVA at 220 kV and above. The HVDC bi-pole capacity, including back-to-back connections, reached 33,500 MW. Some planned transmission systems were delayed due to issues such as right-of-way problems, delays in forest clearances, contractual issues, land acquisition difficulties, and the COVID-19 pandemic. However, other unplanned systems were also commissioned during this period.

Recently, CEA released a draft amendment to the “Manual on Transmission Planning Criteria, 2023.” The amendment introduces a new chapter detailing the procedures for planning electric power transmission systems and updates parameters for certain conductors.