For the longest time the state of Punjab had to live with a strange dichotomy. A state, prosperous and cash rich – thanks largely to its agricultural successes – Punjab remained strikingly poor in power; its record in meeting the energy needs of its growing population and burgeoning industry sector dishearteningly low. In fact, the state’s ailing power infrastructure and its inability to cater to the rising energy demands have never been more apparent than in the last 8-10 years. Around 2009, the situation became particularly bad as the state was experiencing a severe shortage of power. This was largely due to the fact that there was no addition to its power generation capacity in over a decade. The situation became so grave, in several parts of the state, that outages rose to crisis levels causing a wave of public outcry and discontent.
It was in this backdrop that the Punjab State Power Corporation Limited (erstwhile PSEB) invited proposals for setting up of a supercritical power plant under Case-2 of tariff based bidding guidelines of Government of India. Under Case-2 framework fuel, technology and location are specified and all the necessary clearances required to set up the project are obtained by the procurer, i.e., PSPCL in this case.
Nabha Power Limited (NPL), initially proposed to be set up at a place near Nabha in Patiala district in southeast Punjab was moved to Nalash, a village in the Rajpura tehsil of Patiala.
After an intense competitive bidding process, L&T Power Development Limited (L&T PDL) emerged as the winner and began implementing through its subsidiary Nabha Power Limited (NPL) what would go on to become country’s first indigenously manufactured Supercritical thermal power project.
In January 2010, NPL signed a 25-year Power Purchase Agreement (PPA) with PSPCL and a Fuel Supply Agreement (FSA) for 5.55 million TPA with South Eastern Coalfields Limited for the project.
Work on the NPL Project began in 2010. With nearly all the engineering know-how, and technological expertise required for the project within L&T work on NPL progressed swiftly despite its challenging scope and aggressive timelines. All the major equipment were manufactured indigenously at L&T’s state-of-the-art manufacturing facility located at Hazira – nearly 90% of the equipment were manufactured in-house by L&T. Additionally, the technological tie-up and JVs with world leaders like Mitsubishi Hitachi Power Systems (Japan), Clyde Bergmann (USA), Howden (UK) and the likes proved crucial to the cause.
L&T-Sargent & Lundy was tapped for its engineering and design services and JVs with Mitsubishi Hitachi Power Systems (MHPS) helped provide the supercritical boilers and steam turbines for the project. L&T’s joint venture with Howden provided design, engineering, manufacture, and supply of axial fans and supplied rotary air-preheaters. L&T Power, meanwhile, had its own sizeable pool of experienced piping engineers, and piping foundry and software, and it supplied its own heat exchangers and power plant vessels.
Of course this is not to say that NPL didn’t face any challenges. There were stringent timelines for completion of Unit-1 (48 months) and Unit-2 (52 months) as per the terms of the PPA, but thanks to the project managements skills of L&T, all the obstacles were overcome without hurting the project deadline.
A critical issue encountered by the project was the delay in commissioning of the dedicated railway siding. As an interim measure, arrangements were made to transport coal using dumpers. However, the matter was resolved, and the siding was commissioned in February 2016. NPL now has a fully operational railway siding and is successfully operating the siding as well as the Wagon Tipplers with highest reliability and safety standards.
Spread over an area of roughly 1200 acres, NPL is a state-of-the-art Supercritical Thermal Power Plant featuring completely automated operations. The Supercritical Technology offers operational flexibility in terms of better temperature control, shorter start-up time and sliding pressure operation. Additionally, it allows for higher efficiency by consuming less fuel and generates lower emissions. NPL’s design heat rate is 2205 Kcal/KWh which is among the best in the country.
NPL features a twin-fire vortex boiler design, which distributes uniform heat flux across the furnace. The sliding pressure operation provides flexibility in operating the units from part load to full load. The vertical mills are designed with hydraulic oil pressure as a function of coal flow with a dynamic classifier in the mill outlet to control the coal fineness. Other notable efficiency efforts include a state-of-the-art automation of complete operations, including automation in coal rake unloading through wagon tipplers.
Normally at a large size supercritical power plant a fair amount of time is required to stabilise the unit, but the team at Rajpura managed to stabilise the unit in a short of span of time and achieved availability of more than 93% during the first year of operation. This, despite there being not much experience of running supercritical plants in the country. The consistently high availability ranging in the 90s is testament to the technical prowess and capability of the dedicated leaders and young engineers stationed at Rajpura.
It has been close to four years since the second 700 MW unit of NPL went online thereby helping it achieve the full envisaged capacity of 1400 MW. The plant’s journey since then has been remarkable in many ways. NPL is in top of the merit order in the state amongst all the thermal power stations providing cheapest source of power to the state grid. The plant contributes approximately 50% of the total power generation during off-peak season in the state and 25% during the peak season.
The distinction with which NPL has been operating since first commencing operations can be seen in the numerous awards and accolades it has won for its exemplary performance. One of its most prized moments came in 2016 when the Bureau of Energy Efficiency, Ministry of Power, Government of India, awarded it the ‘Best Thermal Power Plant’ award at National Energy Conservation Awards.
Besides, a systemic approach to safety as well as O&M with a range of management systems certifications such as QMS (ISO 9001:2015), EMS (ISO14001:2004) and OHSAS (OHSAS18001:2007) add to its already impressive credentials. The plant has also received NABL accreditation for its coal testing lab.
NPL has kept a watchful eye on its environmental footprint too. It consistently achieving close to 100% Dry Fly Ash Utilisation year after year is ample proof of its seriousness. Additionally, NPL holds the distinction of being a zero-liquid discharge facility.
NPL is also gearing up to meet changing environmental norms. While the latest notification issued by the Ministry of Environment, Forest and Climate Change (MoEFCC) on emissions are mainly intended to put a check on conventional thermal power plants – a supercritical power plant has a significantly smaller environmental footprint –NPL too needs to install additional control measure for air emissions.
To this end, it has already finalised the technology and is currently seeking regulatory approvals. Officials in-charge of operations suggest that it’s nearly impossible to meet the deadlines that are being stipulated by the Central Electricity Authority (CEA). This is due to a number of factors such as uncertainty on benchmark cost, securing feedstock and regulatory capex approvals.
NPL has already been engaged in serious discussion with CEA, CERC and MoEFCC to bring about greater clarity on the norms and the mechanism for pass through of costs.
In a little more than three years, NPL has become critical to Punjab’s power requirement and is continuously and reliably meeting the state’s energy demand. The success of the project has encouraged the government of Punjab to sign a memorandum of understanding with NPL to explore the possibility of further expanding the project scope with an additional 700-MW unit at the plant site.