Cleaning coal based power
Winter’s onslaught is not a particularly pleasant thing for those living in Delhi NCR. The level of air pollution shoots up invariably, days get hazy, breathing becomes problematic, schools close for a few days and then the news goes out of fashion on news channels and people get used to the pain. While immediate trigger every year is the paddy burning in surrounding areas, the more discreet and nationally widespread problem of air pollution which is thermal power plants, does not get enough attention unless there is a news about government closing some plant or the other under court orders. Only a few weeks back, Delhi government temporarily shut down Badarpur thermal power plant of NTPC as air quality in the city deteriorated too much and courts came down heavily asking the government what it was doing to fight the menace.
Earlier this year, in the month of May, the government told Parliament that a total of 19 thermal power plants across India were found violating the environment guidelines, including on installation of pollution control equipment. In a written reply, the then environment minister Prakash Javadekar informed Lok Sabha that “Polluting industries including Power plants are required to install pollution control equipment to meet the prescribed effluents and emission standards as specified in the environment clearance, consent and the guidelines to control the emissions of highly polluting industries.” He had informed further that the CPCB has issued directions to the noncompliant thermal power plants. Out of over 200 thermal power plants of the country, about 116 are coal-based.
According to the data, four of these plants are in Chhattisgarh, three each in Uttar Pradesh and Jharkhand and two each in Bihar and West Bengal. Andhra Pradesh, Gujarat, Maharashtra, Odisha, Rajasthan also have one such power plant. Fortunately, the problem of pollution from coal based thermal power plants, though not new, is not getting increasing attention which is a welcome development. But what makes these plants so bad and what are the options in dealing with these?
A couple of years ago, the nonprofit public interest research and advocacy organization Centre for Science and Environment (CSE) conducted a study according to which NTPC, India’s largest coal based power producer, was way below the prevailing standards across various parameters. The study, titled ‘Heat in Power’ analyzed 47 plants over 16 states representing over half of the thermal power generation capacity and concluded that the Badarpur plant was the most polluting power plant of the country.
The study analyzed and rated coal-based thermal power plants on multiple environmental and energy parameters and found around 18 of the 47 plants as having a score less than 20 per cent, based on approximately 60 parameters. It declared NTPC’s Badarpur plant, contributing about 8 per cent of Delhi’s power, as the poorest performing plant. The plant accounted for anything between 80-90 per cent of the particulate matter, SOx and NOx from the energy sector in Delhi. As per CSE, which advocated the closure of the Badarpur plant, the 767 acres fly ash pit beside the plant, has grown at an alarming rate.
The report of the CSE generated wide public debate and is said to have played a role in government’s change of policies on various parameters including air pollution, water conservation, ash utilization and monitoring systems. The government proposed to control emissions of particulate matter (PM), sulphur dioxide, nitrogen oxides and mercury and also cut water use by coal-based thermal power plants.
Experts say the proposed changes are significant as India currently has poor standards to check emissions from the thermal power sector. The new standards are estimated to cut PM emissions from new thermal plants (after 2017) by 25 per cent, sulphur dioxide emissions by 90 per cent, nitrogen oxides by 70 per cent and mercury by 75 per cent. The plant set up after 2003 will come under slightly relaxed norms. According to CSE, the new standards could lead to an 80 per cent cumulative drop in freshwater withdrawal by thermal power plants.
Broadly, Indian thermal power plants are among the most inefficient and polluting of lots. The average efficiency of the Indian plants is under 35 per cent, one of the lowest among the major power producing countries and large number of plants operate at only 60-70 per cent capacity. The CSE report had found that the average carbon dioxide emissions from Indian power stations were 14 per cent higher than the average in China. The Indian thermal power plants also utilize only 60 per cent of their fly ash generation and used a lot more water compared to the plants elsewhere in the world.
Alarmed by the possible environmental impact of coal based power plants, government has sprung into action. Besides tightening emission norms, it has also made it mandatory for new coal based plants to operate on supercritical technology. The basic difference between supercritical and the subcritical plants, which constitute most of the country’s plants, is the boiler which makes it more efficient. In supercritical boilers, water directly converts into steam without wasting energy in first boiling water, thus reducing coal consumption and reducing carbon dioxide.
For any foreseeable future, India would heavily depend on coal based power because of multiple reasons that range from low cost availability of coal to price of alternative fuels. As such, it is imperative that the country moves towards a cleaner and more efficient coal based power generation. This requires actions on multiple fronts, namely, tightening of emission norms, gradual but definite push towards clean coal technology, improving fuel mix to get better calorific results, higher capacity utilization, reducing water usage and increased utilization of fly ash. It is good that government is seized of the matter, but action is required at a much faster pace before any significant and visible impact could be felt on ground. Surely, air pollution will remain a problem in India for a long time, fixing coal based power generation sector could be a significant achievement.