Punjab State Transmission Company Limited (PSTCL) was carved out of the Punjab State Electricity Board in 2010. With a line length of 12,377.52 ckt. km and a transformer capacity of 37,708.67 MVA, the utility is one of the largest transcos in the country today. Over the years, PSTCL has implemented several initiatives to improve its operational performance such as remote monitoring, the use of HTLS conductors and hotline maintenance. As of November 2020, the transmission loss stood at 2.58 per cent, significantly lower than the loss level of over 4 per cent in 2016-17. PSTCL has also maintained a system availability of 99.97 per cent in the past fiscal.
Going forward, the company has planned a capex of almost Rs 21 billion from 2021-22 till 2024-25. Further, it has planned physical network additions of 503 ckt. km of line length and 4,652 MVA of substation capacity by 2022-23, as well as schemes for system strengthening.
Company overview, network and operational performance
PSTCL’s transmission network comprises transmission assets at the 400 kV, 220 kV and 132 kV voltage levels. Post the unbundling, capital investments were made to strengthen and enhance the capacity of the transmission network in the state. As of March 2020, the total length of PSTCL’s transmission lines stood at 12,377.52 ckt km. The maximum increase of 4.27 per cent in line length over the past four years has been at the 220 kV level.
The transco’s substation base stood at 171 as of March 2020, an increase of 0.59 per cent from 2016-17 levels. Of this, 101 substations are at the 220 kV level, registering a CAGR of 2.42 per cent during this period. The number of 132 kV substations has decreased from 69 to 65, registering a negative CAGR of 1.97 per cent.
PSTCL’s transformers base stood at 629 as of March 2020, recording a CAGR of 1.19 per cent over the past four years. For 2019-20, its total transformation capacity stood at 37,708.67 MVA.
In terms of its operational performance, PSTCL has been successful in reducing its transmission losses from the 2016-17 level while maintaining a high system availability.
The transco has been implementing various initiatives for the upkeep of its network, thus ensuring optimum performance. It has implemented remote control operations at a few of its substations. Further, to address the issue of overloading, measures for de-loading such as the installation of HTLS conductors that allow greater flow of power through the same corridors are being undertaken.
For preventive maintenance of lines, special maintenance drives, like tightening of dead-end jumpers, tree trimming and washing of porcelain disc insulators, are being carried out. Also, anti-fog disc insulators have been installed at strategic locations to safeguard from tripping in foggy seasons. Offline cleaning of porcelain disc insulators with 400 kV transmission lines is also being carried out.
Further, hotline maintenance activities, like jumper tightening disc insulator replacement and repair of substation yard equipment, have been started. Hot line maintenance activities have also become a regular feature.
As per data shared by the company, PSTCL’s total revenues for 2019-20 stood at Rs 13.64 billion rising from Rs 12.81billion in the previous year, recording a growth of 6.48 per cent. The company, however, had a net loss of Rs 335.70 million during this period, as compared to a net loss of Rs 81.7 million in the previous fiscal.
Future plans and investments
The planned capex for 2020-21 is Rs 2,170.60 million. Over the next four years, that is, from 2021-22 to 2024-25, PSTCL plans to incur an annual capex of Rs 5,828.70 million, Rs 5,683.10 million, Rs 4,500 million and Rs 4,950 million, respectively.
As per data from the 19th Electric Power Survey, the energy consumption in Punjab is expected to reach 71,508 MUs by 2024-25. The peak requirement during the period is expected to reach 17,217 MW. Considering the load requirement of 15,654 MW by 2022-23, PSTCL envisaged that the existing generation from its units is likely to be about 6,000 MW. Hence, the remaining requirement of around 9,950 MW has to be sourced from outside Punjab, that is, from Powergrid’s 400 kV interstate grid. To meet the growing demand, a reliable, adequate and robust transmission network would be required.
In terms of physical network additions, PSTCL is planning to add 503 ckt. km of line length from 2020-21 to 2022-23 and over 4,652 MVA of substation capacity during this period with the majority of infrastructure additions at the 220 kV levels.
Its future plans include augmentation and addition of 220/66 kV and 66/11 kV transformers at the 220 kV grids as well as augmentation of bus bars, extension in control room buildings, and other works related to system strengthening. Further, it plans to set up substations at the 400 kV level, including one based on AIS technology. It also has plans for the replacement of existing conductors with HTLS conductors.
Further, certain 220 kV grids have single 100 MVA, 220/66 kV transformers, which will be augmented with additional 100 MVA, 220/66 KV transformers, keeping in mind the space availability. The implementation of OPGW-based reliable communication at 132 kV and above substations has been planned, along with the digitalisation of PSTCL’s existing substation at Passiana.
For the SLDC functions, most of the planned schemes are related to the installation of remote terminal units (RTUs) across the state. The RTUs are to be installed on various substations and are to be integrated with the SCADA system.
In the future, Punjab is expected to have 4,772 MW of solar and 50 MW of small-hydro in 2022-23. To this end, PSTCL has submitted that when the connectivity of such projects will be finalised (other than the ones already identified to be connected at the 132/220 kV level), it will approach the commission to allow expenditures/costs for such schemes.
Challenges and the way forward
The weak financial performance and constrained liquidity profile of PSTCL is a cause for concern. Thus, the transco requires proactive support from the Punjab government to ensure the timely recovery of dues from the counterparty.
That said, PSTCL’s network modernisation and augmentation initiatives are expected to ensure that the transco maintains its strong transmission availability and the state is able to meet its future power requirements.