Overview

Transmission system plays an important role in supply of power to the consumers through the vital link between the generating stations and the distribution system. The energy resources like coal, hydro and renewable are unevenly distributed in India. Coal reserves are mainly available in Central and Eastern part of the country, whereas hydro energy resources are primarily available in Himalayan Range in the Northern and North-Eastern parts. Renewable resources like wind and solar potential are also mainly concentrated in states like Tamil Nadu, Andhra Pradesh, Karnataka, Rajasthan, Maharashtra, Gujarat & Ladakh etc. The major load centres of the country are located in central part including Northern, Western and Southern regions. This skewed distribution of resources necessitated development of robust transmission system including establishment of inter-regional corridors for seamless transfer of power from surplus to deficit regions/areas. In this process, it enables access to power generation from anywhere in the country to various consumer spread throughout the country. The transmission system has expanded over the years for evacuation of power for evacuation of power from generating stations to load centre through Intra State and Inter State Transmission System. The progressive integration of regional grids started in 1992, and on 31st December 2013, our country achieved 'ONE NATION'-'ONE GRID'-'ONE FREQUENCY' with synchronous interconnection of Southern Region Grid with rest of the Indian Grid with the commissioning of 765kV Raichur-Solapur Transmission line. However, there were constraints in market operation due to transmission congestion resulting into market splitting and different market prices in different regions. During 2013-14, about 16% of electricity transacted through power exchanges was constrained due to transmission congestion. Further, strategically important Ladakh region was not interconnected with national electricity grid. The present Government after assuming power in 2014, has given emphasis to have congestion free transmission network, so that there is no constraint in flow of power from surplus region to deficit region. Accordingly, transmission system in the country has been continuously strengthened with addition of transmission lines and inter-regional capacity as under:

 

Addition in Transmission line (ckm)

Addition in Transformation capacity (MVA)

FY 2014-15

22,101

65,554

FY 2015-16

28,114

62,849

FY 2016-17

26,300

81,816

FY 2017-18

23,119

86,193

FY 2018-19

22,437

72,705

FY 2019-20

11,664

68,230

FY 2020-21

16,750

57,575

FY 2021-22

14,895

78,982

FY 2022-23 (till Oct. 22)

7,042

40,657

Total

172,422

614,561

With the above transmission capacity addition, the country has become one of the largest synchronous interconnected electricity grids in the world with 4,63,758 ckm of transmission line and 11,45,107 MVA of transformation capacity (as on Oct.22). Besides, our inter-regional capacity increased by whopping 212% to 1,12,250 MW since 2014. 
The above transmission capacity addition has benefitted in development of power sector in the country. Some of the major ones are as under:- 
  • Transmission Congestion, experienced earlier in 2014, along with market splitting has become a rarity now, resulting into discovery of single price across the power market. Volume of electricity that can not be cleared in Power Exchanges as percentage of Unconstrained Clear Volume has reduced to only 0.06% in 2020-21 as compared to 16% in 2013-14. 
  • High Altitude border areas of Ladakh got interconnected with national electricity grid in January 2019 with the commissioning of 220 kV Srinagar- Leh line. This helped the people of Ladakh to get access to 24x7 quality power from the national Grid. 
  • Transmission and Distribution infrastructure of our North Eastern States including Sikkim are strengthened with implementation of two Central Sector Schemes namely, North Eastern Regional Power System Improvement Project (NERPSIP) and Comprehensive Scheme for strengthening of Transmission & Distribution in Arunachal Pradesh and Sikkim. Implementation of these Schemes would improve the reliability of State Electricity Grids of North Eastern Region and enable the end-consumers to draw 24x7 power from the Grid.
  • Transmission System is playing a catalyst rote in energy transition of our country, by extending the grid to renewable rich areas and facilitating the Renewable Energy projects to connect into the grid. Continuing transmission capacity addition has helped in increase of Renewable Energy (excluding hydro) by three times from 35.52 GW in 2014-15 to 104.88 GW in 2021-22.
  • This huge transmission capacity has facilitated seamless transfer of power from power surplus regions/areas to power deficit regions/areas and thus optimizing the use of generation resources as well as meeting the demands of end consumers without any transmission constraints. Peak and Energy Deficit have reduced to 0.4% in 2020-21 in comparison to more than 4% in 2013-14.