New Delhi: State-run NTPC Ltd has been facing problems at several of its power projects due to issues related to equipment supplied by Bharat Heavy Electricals Ltd (Bhel), said several people aware of the developments.

Turbine-generator (TG) sets supplied by India’s largest power generation equipment manufacturer to the country’s largest electricity utility have developed problems at Bongaigaon (Assam), Vallur (Tamil Nadu), Rihand and Faridabad (UP) plants over the last three years.

This comes in the backdrop of ongoing investigations into the explosion at the recently commissioned 500 megawatts (MW) unit of NTPC’s 1,550MW Unchahar plant, the equipment for which was supplied by Bhel.

The project supplies electricity to Uttar Pradesh, Haryana, Himachal Pradesh, Jammu and Kashmir, Punjab, Rajasthan, Chandigarh, Delhi and Uttarakhand.

To be sure, the blast was in the boiler area and the Union power ministry has set up a high-level committee headed by P.D. Siwal, member-thermal at the Central Electricity Authority (CEA), to investigate it and suggest measures to prevent such incidents.

NTPC has also set up a committee headed by executive director (operations) S.K. Roy to investigate the incident wherein the economizer duct blew, releasing flue gas and steam.

“There have been some issues regarding TGs for which we have been in constant touch with Bhel. Designs keep on evolving and changing. We faced a problem with all three TGs at Bongaigaon," said a senior NTPC executive requesting anonymity.

Another NTPC executive, who, too, did not want to be identified, confirmed the TG failures across several of the utility’s power generation plants.

The failures assume significance given that India’s largest power generator runs 105 coal-fuelled units, with its projects accounting for 16% or 51,635MW of the country’s installed power generation capacity of 331,117.58MW.

While an NTPC spokesperson did not respond to queries emailed on 3 November, a Bhel spokesperson in an emailed response said, “Bhel equipment is of proven technology and working satisfactorily at more than 300 installations in India, including 86 sets in NTPC alone. Bhel-supplied thermal sets have consistently exceeded national average efficiency parameters and (have been) awarded for meritorious performance."

In an attempt to keep pace with the fast-changing electricity sector, Bhel is positioning itself as a transportation solutions provider, particularly in crowded urban settings, Mint reported on 17 February.

The state-run firm wants to become a turnkey metro rail end-to-end solutions provider and also manufacture electric vehicles such as buses, cars, two-wheelers and boats.

“The high level of quality and reliability of Bhel products, manufactured by acquiring and adapting some of the best technologies from leading global OEMs (original equipment manufacturers) is a testimony to its adherence to international standards," the Bhel spokesperson said in the 7 November response.

“During a lifespan of 30 to 35 years of a thermal set, issues reported during operation are promptly attended to by Bhel experts. Bongaigaon, Rihand and Faridabad sets have been restored to normal operation and are working satisfactorily. Work on the TG set for NTPC Tamilnadu Energy Co. Ltd is underway and the set shall be restored to normal operation shortly," the spokesperson added.

Experts believe corrective measures can be taken.

“NTPC has a longstanding relationship with Bhel. NTPC should have known what the flaws in the equipment, if any, are and devise test procedures to ensure that those flaws are detected in time within the warranty period," said Anil Razdan, former power secretary.

“As long as NTPC follows the standard operating procedures, there shouldn’t be a problem. However, if these problems persist, it is a buyer’s market and NTPC should have no problem in going to other vendors," Razdan added.