States like West Bengal, Haryana, Rajasthan and Tamil Nadu are openly flouting the Centre?s policy to phase out high-emitting 500 mw sub-critical power units in their capacity addition programmes.
West Bengal Power Development Corporation (WBPDCL) has adopted the outdated technology for its Sagardighi expansion power project. Utilities in Haryana, Rajasthan, Madhya Pradesh and Tamil Nadu are also developing sub-critical power generation capacities. However, most of these projects are based on 600 mw units, which offer better economies of scale and help in reducing per mw fixed cost of the power projects. Moreover, unlike WBPDCL’s Sagardighi project, the projects in other states were envisaged during the previous Plan, when the ministry had not yet issued any direction on usage of technology for the 11th Plan capacity addition programme.
As super-critical units are more energy-efficient and environment-friendly than sub-critical ones, the power ministry decided to introduce this clean technology as part of its strategy to reduce carbon footprints of the domestic power sector. In a circular issued on October 21, 2009, the power ministry has stipulated usage of super-critical technology as a key parameter for assessing a project’s eligibility for coal linkage.
WBPDCL had initially envisaged putting up two 660 mw super-critical units under the project. But after two years, the WBPDCL’s board decided to go for 500 mw sub-critical units. ?Our recommendation for supercritical units still stands,? a senior official in the Central Electricity Authority told FE. The state utility on November 20 initiated tendering for the implementation of the Sagardighi project after securing the power ministry’s clearance. The deviations would not compromise the developer’s eligibility for mega power project benefits.
Environmental concern aside, the WBPDCL’s decision does not make any commercial sense either. Super-critical plants consume 3% less coal per mw of electricity generation compared to sub-critical units. With coal prices rising, a fuel-efficient technology can help developer keep generation costs in check. Besides, super-critical units in India are entitled to carbon credit benefits and offer a new stream of revenue for developers.
Further, the state utility will have to acquire additional land for making up the 320 mw capacity shortfalls that would arise from its decision to choose sub-critical units over super-critical ones. But the state utility maintains that it chose sub-critical units because they are easy to operate and maintain which is not possible with super-critical technology which requires stringent, specialised maintenance practices. The technology is new and has not yet been tested in India. As of now, there is no supercritical unit in operation in the country. “Unlike sub-critical units, supercritical plants require very specialised, stringent maintenance practices,” a senior official in the WBPDCl, told FE.
“Besides, provenness of the technology has also not been established so far,” he said while marshalling arguments in support of the state utility’s decision to choose sub-critical units over supercritical ones for the Sagardighi project. He, however, admitted that the power ministry was indeed insisting on the WBPDCL using supercritical units for the project. However, state utilities like Rajasthan Rajya Vidyut Utpadan Nigam, Maharashtra State Power Generation Company and Andhra Pradesh Power Generation Corporation as well as NTPC and DVC are using supercritical technology at power projects.