Transmission Corporation of Andhra Pradesh Limited (APTRANSCO), the state transmission utility of Andhra Pradesh, has been continuously improving its transmission losses and deploying new initiatives. Incorporated in 1999 after the unbundling of the erstwhile Andhra Pradesh State Electricity Board, the transco is responsible for the construction, operation and maintenance of power transmission infrastructure in the state. Today, it is one of the largest power transmission utilities in the country covering a geographical area of around 0.16 million square km and catering to a demand of almost 9,000 MW. The company currently owns and operates 322 substations and 28,000 ckt. km of line length, and plans to add nearly 180 substations and over 8,400 ckt. km of lines over the next five years. Since its inception, the company has been making efforts to strengthen its system reliability and modernise its operations to ensure the highest degree of availability. APTRANSCO has achieved a transmission loss level of around 3 per cent, among the lowest in the country, for which it has won several awards. Further, it has been at the forefront in the adoption of latest technologies available for substations and transmission lines, leading the way for other utilities in the country. Stepping up its technology efforts, it is now also working on setting up one of the largest energy storage projects for renewables in the state.
Network size and growth
As of February 2019, the total transmission line length stood at 27,884.97 ckt. km. Of this, around 41 per cent is operated at the 200 kV level, 39.96 per cent at the 132 kV level and the remaining at the 440 kV level. The line length grew at 28 per cent on a year-on-year basis, with over 2,000 ckt. km added during 2017-18 as against 1,616 ckt. km in 2016-17. In 2018-19, 1,570 ckt. km of lines were added as of February 2019. The maximum line length was added at the 400 kV level (46 per cent), followed by 132 kV (30 per cent). Meanwhile, 18 new substations were added till February 2019 with maximum addition at the 220 kV level (33.3 per cent), followed by 400 kV and 132 kV with 22.2 per cent each.
With respect to transformer capacity, APTRANSCO added 5,021 MVA of transformer capacity in 2018-19. Of this, about 17.28 per cent is operated at the 220 kV level, 18.28 per cent at the 132 kV level and the remaining 64.44 per cent at the 400 kV level.
The utility has made continuous efforts to enhance system efficiency. This is reflected in its low level of transmission losses and high system availability. APTRANSCO’s transmission losses have remained below 4 per cent over the past few years and decreased from 3.97 per cent in 2012-13 to 3.13 per cent in 2017-18 and 3.11 per cent till February 2019. The company has been able to overachieve its transmission loss level targets in the past five years. In 2016-17, transmission losses were recorded below the 3 per cent mark at 2.92 per cent. For this, it won the Golden Peacock award for sustainability in 2018. The company also won the IPPAI award for best transmission utility and the CBIP award for the best performing power transmission utility in 2018. Meanwhile, system availability has remained constant at 99.9 per cent throughout 2012-18 (99.98 per cent in 2017-18), one of the highest in the country. Ongoing efforts to this end indicate that the company will soon achieve the 100 per cent target.
In 2017-18, the transco’s total revenue stood at Rs 15.36 billion, a 29.18 per cent increase over the previous year. Since 2013-14, its total revenue has increased by over 5 per cent. This can be largely attributed to the increase in the tariff rate from Rs 91.36 per kW per month in 2016-17 to Rs 95.37 per kW per month in 2017-18. However, in the past five years, net profits have declined by 63.58 per cent. Net profits stood at Rs 1.23 billion in 2017-18 as compared to Rs 1.56 billion in 2016-17. The transco’s capex stood at Rs 18.22 billion in 2017-18, recording a compound annual growth rate of 7.34 per cent from 2013-14 to 2017-18. The debt-equity ratio stood at 1.73 in 2017-18.
APTRANSCO is planning to set up a battery energy storage system with a capacity of 250-500 MW with two to four hours of storage in order to address the morning and evening peak deficits, and intermittency problems due to increased use of renewable energy. The company had proposed to recover 70 per cent of the annual charges of setting up the storage system from renewable energy developers and the remaining from the distribution licensees and open access consumers. However, it is yet to submit a detailed petition in this regard to the commission. In another development, APTRANSCO invited expressions of interest in April 2019 for setting up one of the largest energy storage projects in the world. The project is aimed at harnessing storage technology to mitigate challenges faced by the transmission grid. The company has also proposed a number of wind evacuation schemes. These include the 400 kV Hindupur substation comprehensive wind evacuation scheme (1,300 MW), the 400 kV Jammalmadugu substation comprehensive wind evacuation scheme (950 MW) and the 400 kV Uravakonda substation comprehensive wind evacuation scheme (2,095 MW). Apart from these, a renewable energy management centre is also under implementation in the state and is expected to be commissioned in 2019-20.The company is also looking to lease out 12 spare dark optical ground wires (OPGW) laid on its transmission network for the telecom business. This will help provide last-mile communication and internet facility in remote areas, and offer an additional revenue stream to the transco.
Earlier in the year, APTRANSCO became the first public sector utility to adopt SAP India Private Limited’s Transmission Utility New Enterprise Solution (TUNES), a platform of digitalised energy management processes. It helps in meeting regulatory, environmental, operational, customer and technological requirements in a far more efficient manner than the conventional enterprise resource planning architecture. The company is also implementing new technology such as hybrid substations, new age high temperature low sag conductors and narrow-base towers. It has already installed 220 kV and 132 kV hybrid substations at Kakinada port and Visakhapatnam respectively. Hybrid substations require less space than air-insulated substations and are more cost effective than gas-insulated substations. The company is implementing quad moose conductors to evacuate power from the Vijayawada thermal power station (under construction) and the Polavaram hydropower project. This has helped the utility save around Rs 300 million per km while also reducing the time of project implementation. The narrow-base towers developed by APtransco are equivalent to monopole towers in terms of corridor requirement besides being easy to erect and maintain.
In view of the rapid industrialisation, the company has fast-tracked its plan to sanction high tension (HT) power connections to every mega industry in the state. It has devised an IT programme for providing HT connections within a short span of time. It has also adopted a fool proof cybersecurity mechanism with robust technologies to avoid any possible hacking or misuse.
APTRANSCO plans to incur a capital expenditure of Rs 2,377.8 million by 2023-24. The majority of this (60.5 per cent) is earmarked for the construction of new lines and substations. About 38.53 per cent will be utilised for the implementation of the supervisory control and data acquisition (SCADA) system and the remaining will be invested in the augmentation of assets.
APTRANSCO plans to add a transformer capacity of 31,779 MVA and an overhead transmission line length of 6,848.80 ckt. km by 2023-24. The highest capacity addition will be seen at the 400/220 kV level at about 38.8 per cent while the maximum line length addition will be added at the 220 kV level at around 52.37 per cent.
In sum, the utility seems well positioned to meet the anticipated growth in demand with significant capacity planned to be added in the near future. Further, the advancements in transmission technologies are expected to help the company improve its operational performance and keep pace with the changing sector requirements.