West Bengal’s energy availability in the past five years or so has seen a significant improvement with both peak and energy deficits of less than 1 per cent. The state’s leading generating company, West Bengal Power Development Corporation Limited (WBPDCL), which caters to more than 56 per cent of the total electricity requirement in the state, has played a key role in this regard.
Established in 1985 with only one generating unit at Kolaghat, the company today owns 26 units. All the coal-fired power stations in the state sector (except those of Durgapur Projects Limited) are under its control.
Being a largely coal-based generator, WBPDCL is currently implementing a host of initiatives to improve the energy efficiency of its thermal power stations. The addition of new supercritical units, renovation and modernisation (R&M) of old units, flexibilisation of its fleet, and retrofitting of plants with more environment-friendly emission control systems and better ash management methods are some of the steps the genco is undertaking.
“Our mission is to produce quality electricity in compliance with regulatory requirements in the most consistent and efficient manner, at a competitive price, through eco-friendly operations, and to undertake capacity addition by adopting modern technology,” says Santanu Basu, chairman and managing director, WBPDCL.
Capacity and performance
As of March 2017, WBPDCL’s installed capacity stood at 4,865 MW, comprising the 1,260 MW Kolaghat thermal power station (TPS), the 1,050 MW Bakreswar TPS, the 455 MW Bandel TPS, the 500 MW Santaldih TPS, the 600 MW Sagardighi TPS and the 1,000 MW Sagardighi Extension TPS.
Of these, the Sagardighi Extension TPS, set up in 2016-17, is the most recently commissioned power station. It houses the first 500 MW of the genco. Also, the project has a natural draught cooling system, which is a first for the company.
The company’s projects recorded a plant load factor (PLF) of 52.35 per cent in 2015-16, compared to a PLF of 62.74 per cent in 2014-15. The highest PLF during 2015-16 was recorded by the Santaldih TPS (Units 5 and 6) at 84.29 per cent, whereas the lowest PLF was recorded by the Sagardighi TPS (Units 1 and 2). The genco produced a total of 19,956 MUs of power in 2015-16, against 23,853 MUs in 2014-15, a decrease of 19.53 per cent.
WBPDCL has implemented a pilot project for energy efficient R&M work at the 210 MW Unit 5 of the Bandel TPS, funded jointly by the World Bank and the Global Environment Facility. The R&M implementation was completed in November 2015 and the unit has been operational since then. “The R&M project has enhanced the capacity from 210 MW to 215 MW and will ensure sustained generation from the unit for the next 15 years,” says Basu.
Further, the genco has a well-defined comprehensive ash disposal and utilisation policy for maximising ash utilisation. Ash utilisation at WBPDCL’s power plants has increased significantly. In 2015-16, the company’s fly ash utilisation was 99.15 per cent, as per the Central Electricity Authority. Dry fly ash from plants is being sold through the tendering process. A new tendering procedure through e-auction is currently in process for the Santaldih TPS, and the company plans to take this up for its other plants as well.
Some of the key initiatives to control emissions have been the installation of various state-of-the-art pollution control systems/devices such as high efficiency electrostatic precipitators (ESPs), dust suppression/dust extraction systems, clariflocculators, settling tanks and decantation chambers. Continuous ambient air quality monitoring stations have been installed at all power plants of over 500 MW generation capacity.
Further, online monitoring of stack is being undertaken at the Kolaghat, Bakreswar and Santaldih TPSs, and is in process for the Bandel and Sagardighi TPSs. Recirculation of the ash pond
water is already being done at the Sagardighi TPS and has also been done at Bakreswar and Santaldih. In addition, upgradation of the ESP for Stage I, Units 1, 2 and 3 of the Kolaghat TPS is in process and the terms of reference for Unit 5 of Sagardighi have been obtained from the Ministry of Environment, Forest and Climate Change.
Besides TPSs, WBPDCL owns six coal blocks, which have been allocated by the Ministry of Coal under the new regime of allocations and auctions (post the Supreme Court order cancelling all coal blocks). These are Pachhwara (North), Barjore, Gangaramchak and Gangaramchak-Bhadulia, Barjora (North), Tara (East and West), and Kasta (East). These mines are yet to be operationalised. “WBPDCL will be able to source around 50 per cent of its coal requirements from the allocated coal mines. This will eliminate coal scarcity and enhance the efficacy of all units, as better generation will improve the PLF and availability along with cost competitiveness,” says Basu.
WBPDCL has appointed mine developers and operators (MDOs) for all the allocated mines. It is among the first few gencos to have executed coal mining agreements with the selected MDOs under the new regime. The remaining statutory compliances for the commencement of mining activities in the coal blocks are also in process.
In addition to the allocated blocks, WBPDCL is the biggest shareholder in Bengal Birbhum Coalfields Limited, a joint venture company formed for mining coal from the Deocha-Pachami Dewanganj-Harinsingha coal block in West Bengal, and holds around 28 per cent share of the coal produced from the block.
One of the key projects being undertaken by WBPDCL is the installation of a supercritical unit at the Sagardighi TPS. This will be the first supercritical power project in West Bengal. Recently, the Power Finance Corporation sanctioned a loan of Rs 27.03 billion for developing the 660 MW Unit 5 of the plant. Construction of the unit will commence shortly and the project is expected to be commissioned by October 2020. The unit will generate 4,209 MUs of electricity.
WBPDCL also plans to undertake R&M of Units 1, 2 and 3 of the Kolaghat TPS. The R&M works are expected to begin from September 2017, and the installation of wagon tipplers will commence shortly.
As a step towards the eco-friendly disposal of bottom ash, the construction of a second ash dyke at the Bakreswar TPP is under way. The dyke is expected to be operational by July 2017.
Apart from these initiatives, WBPDCL is committed to adopting clean coal technologies and is in active interaction with the Japan International Cooperation Agency on the issue. It is also looking at flexibilisation of its power plant fleet, and exploring battery storage for renewable and thermal energy.
WBPDCL recorded a total income of Rs 73.11 billion for the year ended March 2015, a 0.91 per cent decline from the Rs 73.78 billion registered in the preceding year. The company’s net profit decreased by about 71 per cent to Rs 228.3 million from Rs 784.3 million during the same period.
Challenges and the way forward
The genco faces a number of challenges as assessed from the company’s regulatory filings. Coal quality is one of the biggest issues hindering the performance of WBPDCL’s power plants. The auxiliary consumption at the utility’s generating stations has been significantly impacted by the quality of coal received at the feeding point. Frequent start-ups and shutdowns, and ageing equipment at its stations are some of the other challenges that the genco has to deal with. Hence, in spite of a number of initiatives being taken by WBPDCL to optimise the running hours of load-bearing equipment, the auxiliary consumption has remained high.
That said, the company is optimistic about future growth. Says Basu, “WPDCL has maintained its lead role in West Bengal. It aims to contribute significantly to achieving the state’s aspiration to become the energy hub of the nation, as also to be the top-rated generation company in the country.”