India’s power transmission segment is growing at an unprecedented pace, mainly due to the thrust provided by the recent policy and regulatory developments, as well as government initiatives. The pace of expansion is expected to continue in the future to meet the government’s renewable energy targets and 24×7 Power for All goals.
An estimated investment of Rs 2.6 trillion is required in the transmission segment to meet the future peak load, which is expected to reach 234 GW by 2021-22. Further, significant renewable energy capacity is likely to be added in the next few years in the backdrop of the government’s 175 GW by 2022 target.
That said, renewables are characterised by variability and uncertainty and a short gestation period. Hence, aside from a robust transmission network, major investments will also need to be made to address intermittency/variability in the system through renewable energy management centres (REMCs), static synchronous compensators (STATCOMs) and static VAR compensators (SVCs).
Also, as part of its Mission 41K, the Ministry of Railways has embarked a plan for the electrification of an additional 24,000 route km, that is, about 90 per cent of the railway broad gauge routes, which would require dedicated transmission lines to be set up. Meanwhile, the government’s e-mobility programme is also expected to alter load profiles, which would require the grid to be made more resilient to variable loads.
A look at the key trends in the transmission network, the infrastructure growth so far, the future growth drivers and the challenges…
Network size and growth
The transmission segment has grown significantly over the past few years, led by the need to cater to the growing load and provide connectivity to generation projects. As of March 2018, the total transmission line length stood at 390,970 ckt. km (220 kV and above) and the AC substation capacity stood at 804,458 MVA. While the line length grew at a compound annual growth rate (CAGR) of over 7.3 per cent, the AC substation capacity grew at about 11.8 per cent between 2012-13 and 2017-18. In addition, the high voltage direct current (HVDC) substation capacity stood at 22,500 MW as of March 2018.
The share of the private sector in the total line length increased from around 2.9 per cent in 2012-13 to 6.9 per cent in 2017-18, while in terms of substation capacity, it increased from only 0.6 per cent to 7.7 per cent. However, Power Grid Corporation of India Limited (Powergrid) continues to dominate the country’s transmission segment with around 145,400 ckt. km of lines and a capacity of 323,715 MVA. The interregional transmission capacity has also grown significantly over the years and stood at 78,050 MW as of February 2018. It increased at a CAGR of over 22 per cent from 2011-12 to 2016-17. Powergrid added a record 15,000 MW interregional power transfer capacity in 2016-17, which further facilitated the smooth exchange of power without any price split.
Renewable energy integration
An ongoing initiative for enabling the integration of large-scale renewable energy into the grid is that of the green energy corridors. Powergrid has devised two schemes for the creation of highways for renewable power transmission, the Greeen Energy Corridor (GEC) I and GEC II. GEC I comprises two systems, one starting from Gujarat, traversing Rajasthan and ending in Punjab, and the other in Tamil Nadu. These have been designed in the potential wind and solar-rich areas. GEC II, on the other hand, focuses on tapping power from the ultra mega solar parks in different states such as Andhra Pradesh, Madhya Pradesh, Karnataka, Rajasthan and Gujarat.
Under the GEC project, state-of-the-art STATCOMs and SVCs are also being implemented to maintain grid stability. SVCs and STATCOMs improve power quality by ensuring stabilised voltage levels and an enhanced power transfer capability of the transmission line.
To further enhance stability and facilitate energy balancing, a forecasting and scheduling mechanism is being implemented at the REMCs. The government has planned to build 11 REMCs across the country, alongside the state load despatch centres (SLDCs), and an REMC at the national level. These REMCs would work in tandem with their SLDCs/regional load despatch centres to enable smooth grid operations.
Significant projects to strengthen the cross-border electricity exchange have also been executed in recent years and some are in the pipeline. In August 2017, India and Nepal inaugurated two new transmission lines for higher levels of electricity transfer – the Katiya-Kushaha and the Raxaul-Parwanipur transmission lines. These will add 100 MW to the 350 MW power that India already supplies to Nepal.
Keeping in view the number of hydropower projects in the pipeline, India is planning high capacity east-west transmission corridors in Nepal that would connect the projects located in Nepal to the load centres in India. India has also planned several interconnections with Bangladesh, including the second Baharampur-Bheramara interconnection. In addition, the two countries have signed an MoU for the supply of 1,600 MW through dedicated high voltage direct current (HVDC) transmission lines. The country is also implementing several interconnections with Bhutan. These are the 400 kV Punatsangchhu I-Lhamoizingkha (Bhutan border), Lhamoizingkha-Alipurduar and Jigmeling-Alipurduar lines.
Another key growth driver for transmission infrastructure expansion is expected to be the electrification of railways. Indian Railways unveiled its Railways Mission 41k initiative in January 2017, with the objective of saving Rs 410 billion over the next 10 years through an integrated energy management system. Under this, 38,000 route km of rail track will be electrified between 2017-18 and 2021-22, to ensure 100 per cent electrification of its broad gauge rail routes. In order to meet its targets, it is focusing on the setting up of transmission lines, substations and transformers.
According to estimates by Edelweiss Research, around 8,000 km of transmission lines will be needed by Indian Railways to provide reliable and secure supply for the Golden Quadrilateral in the first phase. This is expected to fuel growth in the transmission segment, as well as create huge opportunities for equipment manufacturers in the country.
Smart grids and electric vehicles (EVs)
Another key area for transmission infrastructure expansion would be smart grids. An initiative to make the transmission grid smarter has been the Unified Real Time Dynamic State Measurement project, which is being implemented by Powergrid. Under the project, Powergrid is installing approximately 1,700 phasor measurement units (PMUs) at all HVDC and 400 kV and above voltage level substations. Under Phase I of the project, around 1,200 PMUs will be installed along with computer hardware and software at 34 control centres. These will pave the way for remote communication and management of power supply. Powergrid has already installed more than 900 PMUs and developed three of the six analytical tools planned under the project.
Further, with the increasing penetration of EVs in the grid over the next few years on the back of the government’s ambitious plans to move to an all-electric fleet, the Indian grid will experience some serious challenges due to EV charging. These are increase in harmonics, line losses and increased reactive power consumption, among others, which could potentially impact power system equipment and create voltage stability issues. This would necessitate investments in grid monitoring and automation, besides investments in reactive power compensation capabilities, which would prevent overloading of the grid.
Concerns and outlook
Several issues need to be resolved to ensure that the grid expansion plans are on track. Securing right of way remains a pressing concern for both private and public project developers, with varying policies and regulations being adopted by different states. Environmental and forest clearances continue to remain the leading challenges in project development. Further, large-scale capacity addition and connection of millions of new consumers to the grid require robust grid planning and empowering system operators and regulators to ensure the effective implementation of relevant policies and regulations.
The transmission segment should continue growing at this pace in order to meet the government’s renewable energy and 24×7 Power for All goals. This will also guarantee that a strong and reliable backbone grid is ready to support the shift in generation mix and distribution loads.