Transmission sector on the move

The article focuses on growth drivers of the transmission sector that is witnessing the upward trajectory movement. - Ashok Upadhyay

The transmission network in India has grown significantly over the past few years driven by the need to support the growing load and provide connectivity to generation projects. India’s power transmission segment is growing mainly due to the thrust provided by the recent policy and regulatory development, as well as government initiatives. Between 2012-13 and 2018-19, the transmission line length grew at a compounded annual growth rate of over 7.5 per cent and substation capacity grew at about 11.8 per cent. 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 consumers. A conductive policy framework has helped the transmission sector to develop consistently at a significant growth rate. The growth is likely to continue over the next few years to meet future peak load, which is expected to reach 235 GW by 2021-22. Further, significant renewable energy capacity is likely to be added in the next few years against the backdrop of the government’s 175 GW by 2022 target.

The renewable energy characterised by variability and uncertainty and a short gestation period. Hence, aside from a robust transmission network, major investments will need to be made to address intermittency or variability in the system through renewable energy management centers. The power transmission segment is currently the most attractive infrastructure investment in India. The key drives will be increasing demand for power, addition of generation capacity including renewable, and new technology adoption for grid modernisation, as well as the need to reduce congestion and enable free flow of power regions. At the intra-state level, the key focus is on upgradation and modernisation of existing networks to cater to the increasing demand since not much network can be added owing to right-of-way issues.

As per National Electricity Plan, 2016- Transmission, a line length addition of 105,580 circuit kilometer and substation capacity addition of 292,000 MVA have been envisaged during thirteen plan period. Corresponding to the addition of lines, a major part of the investment will be on the erection of towers. On an average towers account for more than 35 to 40 per cent of the cost involved in the construction of transmission line. Along with their foundations, the towers constitute almost half the cost involved in the construction of transmission line. Therefore, market opportunities for technology providers and transmission tower players are likely to grow significantly in the coming years.

With the increasing renewable energy generation, the grid is expected to extend to far-flung areas. As the gestation period of renewable energy projects such as solar and wind is short, the associated transmission projects need to be completed at a fast pace in order to facilitate the evacuation of energy. This requires speedy development of transmission lines and towers using advanced technologies such as light detection and ranging for surveying drones for patrolling and helicopters for tower erection and stringing.

Key Drivers

Key drivers for development of transmission infrastructure in the country are as follows:

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. Government has devised two schemes for the creation of highways for renewable power transmission, the green energy corridor I and green energy corridor II. Green energy corridor I comprises two systems, one starting from Gujarat, travelling Rajasthan and ending in Punjab, and the other in Tamil Nadu. These have been designed in the potential wind and solar rich areas. Green energy corridor II, on the other hand, focuses on tapping power from the ultra-mega solar parks in different states such as Andhra Pradesh, Madhya Pradesh, Karnatak, Rajasthan and Gujarat.

Under the green energy corridor projects, advance technologies or systems are also being implemented to maintain grid stability. SVCs and STATCOMs are used to improve power quality by ensuring stablised voltage levels and an enhanced power transfer capability of the transmission line. To further enhance stability and facilitate energy balancing and scheduling mechanism is being implemented at the renewable energy monitoring centers. The government has planned to build 11 renewable energy monitoring centers across the country, alongside the state load dispatch centers and an REMC at the national level. These would work in tandem with their state load centers or national load dispatch centers to enable smooth grid operations.

Cross-border links

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. These will add 100 MW to the 350 MW power that India already supplies to Nepal. Keeping in view the number of hydro power projects in the pipeline, India is planning high capacity east-west transmission corridors in Nepal and would connect the projects located in Nepal to the load centers in India. India has also planned several interconnections with Bangladesh, including the second Baharampur-Bheramara interconnection. In addition, the two countries have signed MoU for the supply of 1600 MW through dedicated high voltage direct current transmission lines. The country is also implementing several interconnections with Bhutan. These cross-border links will drive the growth of transmission infrastructure in India.

Rail electrification

Another key growth driver for transmission 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 41,000 crore 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, sub-stations and transformers. 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 transmission equipment manufacturers in the country.

Smart grid and electric vehicles

Another key area for transmission infrastructure expansion would be smart grid. An initiative to make the transmission grid smarter has been the Unified Real Time Dynamic State Measurement project, which is being implemented by Powergrid. Further, with the increasing penetration of electric vehicles 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 electric vehicle 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 investment in reactive power compensation capabilities, which would prevent overloading of the grid. The government is also planning to provide several incentives and regulatory framework to promote e-vehicles in the country.

Private sector participation

Promoting competition in electricity sector is one of the aims of the Electricity Act, 2003. In the spirit of encouraging competition, various reform measures have been initiated by the Central and State Governments. Ministry of Power came out with competitive bidding guidelines were put in place for enabling competition in power transmission to enable private sector investments in the sector which allowed price discovery through market-based mechanism. This ensured that private transmission companies are allowed equal platform and opportunity to access the market as the public companies but most importantly it ensured competitive prices to benefit both, the consumers and the market. The initiatives undertaken by the Government of India and various states have led to competition in power transmission. India is one of the few countries where Transmission Sector has been opened up for private participation and has garnered significant interest from private players. However, the spirit of competition and private participation in the Indian electricity transmission sector is still in the nascent stages. With the huge generation capacity addition and improved generation with fuel issues getting sorted out for existing capacity, a corresponding increase in transmission capacity is needed to ensure that power generated reaches the end consumer. Major part of the total investment required has to come from private sector. Clearly, successful PPP in transmission would be vital to meet the huge investment and capacity enhancement target in transmission.


Despite having more than 350 GW of installed generation capacity, some of the states in the country continuously facing power deficit. One of the major reasons for this situation is the inadequate transmission capacity, not matching the generation capacities and load requirements. Power evacuation is turning out to be a bigger problem than power generation for the country. Plants supplying electricity to state electricity boards under long term power purchase agreements, lost part of generation due to transmission capacity bottlenecks. The Southern region is anticipated to face a peak-time shortage, whether other regions anticipated surplus power. However, the power transmission constraints do not allow met shortfall by the surplus power. Resource rich states like Chhattisgarh are also unable to evacuate the excess power. With a typical transmission project requiring ~4-5 years to get commissioned and inordinate delays expected in securing forest clearance in the region, it seems that the number of projects running below capacity, owing to transmission bottlenecks, will only increase in the near future.

Several issues are 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.

Many transmission projects have faced delays because of the developer’s inability to acquire land and get timely clearances from all stakeholders. There have been instances of transmission lines being forced to take a different route than planned, resulting in the entire project budget going out of control. Power transmission constraints have also made it difficult to evacuate excess power and channel it to regions that face shortages. Projects have had to purchase power from costlier sources while others remained under-utilised. Hence, there is an urgent need to timely address underlying issues in the transmission sector to ensure power demand is effectively met in the future.

Key issues faced by transmission project developers include delay in land acquisition as well as obtaining right-of-way and environmental clearances. Inadequate investments at the intra-state level, which are restricting the flow of power from surplus to deficit areas, and the ineffective implementation of open access transactions, also pose serious challenges for the transmission segment. There is an urgent need to create liquidity in the market to sustain private interest. State utilities also need to ensure payment security to make their projects as viable as the central level projects. With the shift to higher voltages and improved technologies, new challenges such as asset management hotline maintenance, emergency restoration of towers, augmentation of test facilities and transportation of heavy equipment’s via roads also need to be addressed.

Way forward

The transmission grid has expanded at a fast pace in the past few years. Despite significant growth, the transmission segment continues to be plagued by certain issues and challenges such as Right-of-Way transmission congestion and inadequate investment in the sub-transmission networks. Notwithstanding these issues, the utilities investment plans for the next few years indicate significant network additions, and hence, more opportunities for transmission tower and equipment market players. The uptake of modern technologies is also expected to increase as there is greater pressure to deliver transmission projects within strict timelines, lower implementation of risks and optimise costs. Since RoW is the key challenge facing the transmission segment, utilities are increasingly deploying double and multi-circuit lines instead of single-circuit lines in order to minimise their RoW requirement. Utilities are focusing on adopting higher voltage levels, specially designed towers and new technologies to gradually increase the power carrying capacity of transmission to optimise RoW. In addition, tower designers are designing compact towers that need less space. New tower designs are coming up that use less steel, have fewer sections and bends, and are easy to transport and assemble. Insulated cross arms are also being used to reduce both the height and width of towers.

Constructing tower foundations is a challenging task, given the risks posed by geology. The importance of selecting the most suited foundation for towers increases as the transmission network continues to expand across varied terrain. The increasing loads from lines that carry higher voltages also require bigger and heavier tower foundations. Given these diverse requirements, it is importance to focus on building appropriate and robust tower foundations.

Significant advancements have been made in tower designs and foundations to meet the transmission infrastructure requirements. These have helped in the expansion of the transmission network at a faster pace and in a cost-effective manner. However, for best results, it is essential to identify the right technology solution for a given transmission project taking into accounts the project terrain and RoW requirements, among other things. It is necessary to choose the best-suited tower installation technique that minimise costs and ensure maximum reliability. Tower structures that can be installed using helicopters are becoming popular, especially, at inaccessible locations.

Even within a state boundary, choked transmission networks are leading to underutilisation of generation capacity. Wind energy generation in Tamil Nadu run below capacity, as the transmission capacity available was insufficient. In addition, the state had a net deficit of electricity and had to purchase power from costlier sources. Going forward, the demand side capacity is expected to further increase with the industry moving towards Open Access. Open access will allow every end-user of electricity in the country to choose from all available transmission lines, thereby, increasing transmission load across the country.


The transmission segment should continue growing at this pace in order to meet the government’s renewable energy target and 24×7 power for all. This will also guarantee that a strong and reliable backbone grid is ready to support the shift in generation mix and distribution loads. Central and private sector transmission utilities have started adopting global practices for the development of transmission line projects. The state transmission utilities also need to align their approach with international standards as the pressure on the intra-state and inter-state transmission system is expected to increase in the coming years with the growing renewable energy integration and increasing medium or short-term flow of power through the grid. The transmission segment is expected to witness a paradigm shift in terms of how projects are planned and executed in the next few years.