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View Points | November 2016

Change norms for clean air

As India´s current policies and norms were found wanting, the proposed draft for new emission standards is a necessary step in the right direction, believes researcher Nayan Nitesh.

India´s pollution challenges are bigger in comparison to other countries. One, because it is a developing nation and two, because large swathes of the country still aren´t exposed to industrialisation as compared to others. As such, if our energy usage is not changed from what it is now, India is likely to be in the grip of pollution for an extended period of time.

Thermal power plants account for a major share of power generation in India, with the sector having witnessed rapid capacity addition at both - the central and state levels, over the last few decades. The major contributors to this mix are coal-based thermal power stations. By the end of 11th Five Year plan, coal-based power plants alone contributed 85 per cent to the total installed capacity of thermal power plants, as against 14 per cent of gas-based power plants. In fact, coal-based power also accounts for a major chunk of the total power generated in the country.

However, capacity additions aside, coal-based thermal power plants are a significant source of emissions. This is a matter of great concern to India, as the resultant impact on human health and the environment is troubling. Coal power generation femits harmful pollutants such as suspended particulate matter (SPM), sulphur oxides (SOx), nitrous oxides (NOx) and mercury (Hg) as well as greenhouse gases (GHG) like carbon dioxide (CO2). Thus, in order to curb emissions, relevant regulatory authorities at the Centre and state level need to revise the existing emission standards for SPM, besides also introducing new standards for other pollutants and further ensuring compliance.

India´s premier fuel is not supreme in quality. Of the total pollution from the industrial sector, coal-based power currently accounts for approximately 60 per cent of particulate matter (PM) emissions, 45-50 per cent of SO2 emissions, 30 per cent of NOx emissions and more than 80 per cent of mercury emissions. Vast reserves and low purchase price of coal have made it one of the cheapest sources of power generation in the country.

In contrast, the uncertainty around domestic gas reserves, its availability and price have adversely impacted existing gas-based power plants and prospective investments. However, coal-based plants also present significant opportunity in regards to efficiency and emissions improvement over the inherently much less emissions-intense gas-based power plants.

While our current policies and norms to overcome this challenge were found wanting and India´s standards for pollution and resource use lag far behind global norms, the current proposed draft for new emission standards is a step in the right direction; though more may be necessary.

SOX and NOX
Other major health concerns are SOX and NOX, for which India thus far has no standards specified, leaving little impetus to deploy emission controls.

The new draft norms are a step ahead in clearly specifying SOX and NOX standards. However, relaxation of older and smaller units to continue to emit 600 mg/Nm3 will remain a major source of concern for agricultural and health pollution. Here it is important to note that the European Union standards - which are in fact considered lax, compared to other countries, also allow for only 200 mg/Nm3 for all older units.

Thus, India should at least target standards of a similar level, if not above. The norms should therefore mandate all existing thermal power plants to comply with 200 mg/Nm3 with an allowed time frame of a few years to reach the target of 100 mg/Nm3.

Furthermore, the risk of pollution remains even after emission control if ash ponds are not well constructed. According to Harvard Medical School, a vast majority of the over 1,300 coal combustion waste impoundments ponds in the United States are poorly constructed, increasing the risk of waste leaching into groundwater supplies or nearby water bodies. Many of India´s coal-based power plants are way below global standards in terms of efficiency and are struggling to dispose fly ash generated by them. Thus, the emission norms by themselves may not be sufficient until best practices and norms are specified for ash ponds. Particulate Matter
Considering the standard of 30 mg/Nm3 for particulate matter (PM), this is a significant step up as compared to previous emission standard of 150 mg/Nm3 and will go a long way in reducing emissions from newly constructed coal-based thermal plants. However, the relaxation for older units constructed before 2003 up to 100 mg/Nm3 and for units from 2003-2006 up to 50 mg/Nm3 is still high permissible PM standards, considering they form the majority of operational units in India.

The proposed 30 mg/Nm3 (PM) emission standard mirrors that of China and Europe. But, it is also important to note that in contrast, smaller units in China are no longer allowed, and most of their existing small plants have been decommissioned.

Meanwhile, according to data filed by the Central Electricity Authority (CEA), approximately 70 per cent of the operational units in India are of sizes less than or equal to 210 MW. These units tend to have the worst net efficiency and plant load factor, added to whihc the number of older units is also significantly higher, thus lowering the practical feasibility of overall reduction in emissions.

Moreover, existing and new plants in China all fall within the 2 tier standard; and existing plants are given a duration within which to comply, with a slightly less stringent standard, failing which they are decommissioned. India providing a three tier structure already allows for relatively lax standards; thus the proposed standards should at least stipulate that ´if older coal plants (built before 2003) are unable to meet the standards, they should be retired earlier´.

Monitoring and Implementation
A study conducted of power plants in India demonstrated that even the previous lax emission norms were not being met by a large number of coal-based thermal power plants. While many reported compliance on paper, their actual emissions far exceeded the previous standards of PM, and recommended standards for SOX, NOX, Hg etc. Simultaneously, monitoring agencies reported facing challenges like being under staffed and thus unable to ensure implementation.

Another notable development is that after China launched its emission standards in 2012, they also added on the Air Pollution Prevention and Control Action plan with specific time-bound objectives for 5-10 year time frame.

Efforts were made to rectify small coal-firing boilers and accelerate construction of desulphurisation, de-nitration and dust removal projects in key industrial sectors. Also, China has a robust plan to switch from coal to natural gas for power generation which means the rate of increase in emission from coal, if not emission itself, will be significantly reduced.

A further challenge in monitoring and enforcement emerges due to the cost implication of retrofitting of emission control kit and the operating cost; so, there needs to be a stricter mechanism to make this work. In China, they have alternatively provided incentives for emission control and slapped fines for exceeding limits, where suited. Thus, in addition to the specification of emission norms, the Chinese government offers incentives such as emission control tariff premiums to encourage installation of emissions controls like flue gas desulphurisers. It is widely recognised that FGD (flue gas desulphurisation) units can help achieve emission standards and actually ensure implementation. In India, very few thermal power plants are currently recommended for installation of FGD and it is yet to be made mandatory by law for all thermal power plants. These norms would work better with monitoring of PM levels by cities to ensure local enforcement. In China, for example, the central government began to disclose names of the 10 best and 10 worst air quality cities monthly; it set targets of PM 2.5 in the three key regions and PM 10 in other key areas, majority of them are seen as compulsory targets. Such measures may be necessary to include and mandate while specifying norms.

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