Assam is witnessing a steep rise in its peak power demand. According to the Central Electricity Authority’s report on the Intra-State Transmission Resource Adequacy Plan for Assam, the state’s peak electricity demand is projected to grow at a compound annual growth rate of 8.51 per cent to 6,363 MW (including upcoming industrial demand) by 2034-35 from an actual peak of 2,812 MW in 2024-25. The growth is being driven by industrial development, urbanisation and expanding rural electrification, placing increasing pressure on the state’s transmission infrastructure. In response, the state is ramping up investments in grid expansion, capacity augmentation and network modernisation.
Assam Electricity Grid Corporation Limited (AEGCL) is the largest state transmission utility in the north-eastern region. Following the restructuring of the Assam State Electricity Board in 2003, AEGCL inherited 3,862 ckt kms of extra high voltage (EHV) lines above the 66 kV voltage class and 38 EHV substations with a combined transformation capacity of 1,636.50 MVA. Since then, its network has expanded substantially. According to the company’s FY 2024-25 true-up petition, AEGCL operated 5,426.24 ckt km of transmission lines and 82 grid substations with a transformation capacity of over 10,000 MVA across different voltage levels as of the end of FY 2024-25. As the state’s power demand shoots up, AEGCL is undertaking further augmentation, reconductoring and capacity enhancement projects to remove existing bottlenecks in its transmission network.
Current performance
AEGCL has consistently delivered strong operational and financial performance. The company has maintained transmission system availability above 99 per cent over the years. In FY 2024-25, average transmission availability stood at 99.08 per cent. Network efficiency has also improved steadily, with transmission losses declining from 3.31 per cent in FY 2022-23 to 3.28 per cent in FY 2023-24 and further to 3.24 per cent in FY 2024-25. This has been supported by the commissioning of new 132 kV and 220 kV substations, augmentation and replacement of power transformers, and the replacement of ageing transmission lines with high-temperature low-sag (HTLS) conductors.
On the financial side, AEGCL reported revenue from operations of Rs 7.19 billion in FY 2024-25, up from Rs 6.22 billion in FY 2023-24. Similarly, net profit improved to Rs 3.05 billion from Rs 1.95 billion, reflecting a year-on-year growth of 56 per cent and providing greater headroom for transmission network investments.
Challenges
Assam’s rapidly growing electricity demand is highlighting the vulnerabilities of its transmission network. Much of the existing network is nearing its operating limits due to sustained load growth and ageing infrastructure. Several 132 kV corridors are experiencing thermal overloading, voltage instability and constraints during contingencies. Insufficient transformation capacity at grid substations is also limiting operational flexibility.
The ageing transmission network is a key concern. Important 132 kV lines, including Bornagar-Dhaligaon, Sonabeel-Depota, Sonabeel-Ghoramari, Ghoramari-Depota, Nalbari-Rangia, Nalbari-Barpeta and Barpeta-Dhaligaon, have been in service for over 30 years. These lines form critical evacuation and interconnection corridors supplying the lower Assam distribution network. However, ageing conductors, deterioration of tower hardware, reduced conductor tensile strength and lower current carrying capacity have affected their performance. As a result, these corridors are increasingly unable to meet rising demand, particularly during summer evening peaks and periods of high agricultural load.
The state also faces a shortage of transformation capacity. Existing transformers have become a bottleneck for power evacuation to downstream substations, restricting efficient utilisation of available generation and transmission assets.
Key initiatives
AEGCL has been implementing a series of network-strengthening measures to tackle these challenges. The company’s focus is on expanding transformation capacity, upgrading transmission lines, improving voltage profiles and modernising substations. A key part of this effort is the Assam Intra-State Transmission System Enhancement Project, which is being implemented with funding support from the Asian Infrastructure Investment Bank (AIIB).
As of October 2025, under the AIIB-funded project, the company was constructing several new gas-insulated substations (GIS) along with associated transmission lines. The project also included the conversion of the existing Gohpur air-insulated substation into a GIS facility and the augmentation of transformer capacity at multiple substations. In addition, new 400 kV, 220 kV and 132 kV transmission lines, line-in line-out (LILO) connections and bay extensions were under developed to integrate the new infrastructure into the state grid. AEGCL had also completed the replacement of conventional ground wire with 636 km of optical ground wire. All 17 contract packages for the project’s transmission and substation works had been awarded, with implementation under way.
Capacitor banks have also been installed at multiple substations to support voltage maintenance at the 33 kV bus. Alongside these works, the utility has undertaken several initiatives to improve network reliability and reduce transmission losses. In FY 2023-24, AEGCL commissioned the 132 kV Hatsingmari grid substation (GSS) and the 132 kV LILO of the Pare-Nirjuli line at Nalkata GSS. This has improved voltage profiles across downstream transmission and distribution networks. The utility also replaced ageing transmission lines with HTLS conductors, upgraded old 25 MVA transformers at several substations, and installed a 160 MVA transformer at the 220 kV Agia GSS to strengthen load-handling capacity.
In FY 2024-25, the company commissioned the 220 kV Amingaon GIS and several new 132 kV GIS. It also continued transformer replacements, capacity augmentation and HTLS reconductoring works. Assets worth Rs 1.46 billion were capitalised during the FY 2024-25.
In FY 2025-26, transformer augmentation at the Nalbari and Rangia GSS is estimated to further reduce transmission losses to 3.21 per cent. Additional projects include new 220 kV and 132 kV lines, LILOs, and 220 kV substations at Khumtai, Jakhalabandha, Bihpuriya, Chaygaon, Nagaon, Agomoni, Sankardevnagar, as well as the 132 kV Amingaon GIS.
Beyond these efforts, AEGCL is strengthening its cybersecurity framework. During the past year, it expanded secure LAN connectivity across substations and offices, deployed an operational technology firewall, renewed endpoint security licences, conducted cyber hygiene training and phishing simulation exercises, and strengthened its secure email infrastructure.
Future plans
In the ongoing financial year, AEGCL plans to complete several high-impact projects aimed at enhancing system reliability and sustaining the long-term downward trajectory of transmission losses. The company expects to commission the New Rangia GIS and Sonapur GIS, along with key transmission links, including the 400 kV single-circuit LILO at Sonapur GIS from the Silchar-Byrnihat transmission line, the LILO of both circuits of the 400 kV Balipara-Bongaigaon line at the New Rangia GIS, and the 220 kV LILO of both circuits of the Amingaon-Rangia double-circuit transmission line. These additions are expected to bring transmission losses down to 3.19 per cent by the end of FY 2026-27.
Alongside network expansion, the company is modernising its existing assets. It plans to upgrade the substation automation systems at the 220 kV Jawaharnagar and 132 kV Matia GSS. The existing systems have become obsolete and could otherwise increase the risk of equipment failure.
AEGCL has also proposed dedicated expenditure on cybersecurity during FY 2025-26 to FY 2029-30, reflecting its continued focus on protecting critical grid infrastructure.
The company’s investment pipeline also points to a significant acceleration in project execution. Capital expenditure is projected to increase from Rs 4.69 billion in FY 2024-25 to Rs 11.81 billion in FY 2026-27. A major contributor to this growth is the AIIB-funded project, under which annual capex is expected to rise sharply from Rs 2.82 billion to Rs 8.74 billion over the same period.
The company’s growth plans are also supported by the state government. In July 2026, the Assam government released the draft budget for the state for 2026-27, in which Rs 46 billion has been earmarked for power evacuation infrastructure. The proposed works include a 400 kV evacuation system through the Chapar-Rangia, Chapar-Agia and Agia-Sarusajai corridors for the Chapar Thermal Power Project, new 400 kV grid substations at Khumtai and Umrangsu, and the modernisation of the Sarusajai 220 kV grid substation. Together with AEGCL’s ongoing investments, these projects are expected to significantly enhance the state’s transmission capacity and meet the growing power demand.
