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Despite Clear Benefits, Why Won’t the Govt. Deploy Flue Gas Desulphurisation?

Despite Clear Benefits, Why Won’t the Govt. Deploy Flue Gas Desulphurisation?

Representative photo: Johannes Plenio/Unsplash

  • Thermal power plants have resisted implementing new emissions standards by repeatedly seeking extensions to the compliance deadline – and the environment ministry has allowed these extensions.
  • Data from the Central Electricity Authority (CEA) and the environment ministry indicate that most thermal power plants are unlikely to comply even within the extended timeline.
  • Meeting some of these standards require the plants to install flue-gas sulphurisation (FGD) systems, which remove sulphur dioxide from the plants’ emissions.
  • A June 2022 study by researchers at the CEA and IIT Delhi analysed emissions and air quality at 240 stacks in 67 thermal power plants across the country.
  • Its most important finding was compelling evidence highlighting the benefits of FGDs – but the authors also cautioned against implementing FGDs for some very curious reasons.

Outdoor air pollution is a growing concern in most parts of India. New Delhi and nine other cities in the country rank among the 25 worst in the world in terms of air quality.

A particular source of concern against this background are coal-based thermal power plants, which are the largest emitters of sulphur dioxide, nitrogen oxides and particulate matter. Higher exposure to these pollutants degrades human health, ecosystems, agriculture and human-made structures.

Despite these facts, and the long time for which they have been known, the Union environment ministry first notified emission standards to regulate these pollutants only in December 2015. Earlier, there were norms only for emissions related to particulate matter. The 2015 emissions standards also specified water consumption limits for thermal power plants and required zero waste-water discharge.

To comply with these new norms, thermal power plants need to install various emission control systems within a specified timeframe. One such system is a flue-gas desulphurisation (FGD) unit, which is well-known to be effective at controlling sulphur dioxide emissions from thermal power plants.

Given the serious health, environmental and social hazards of air pollution, our priority should be to reduce these emissions as much and as soon as possible. Unfortunately, the power plants’ compliance with the norms – including FGD implementation – doesn’t inspire confidence.

Repeated revisions

The Dadri thermal power plant. Photo: NTPC website

Thermal power plants have resisted implementing the new norms by repeatedly seeking extensions to the deadline. The environment ministry has caved and has revised the deadlines several times already.

At first, all thermal power plants were required to comply by December 2017. Most of them missed this deadline. Just a month earlier, in fact, compliance with the norms had turned into a legal issue. In an ongoing matter related to air pollution, the Supreme Court considered the implementation of the new norms to be an important mitigative measure. The Association of Power Producers, a group of eight major generating companies in India, had impleaded themselves in this matter and argued that the government should ease the norms and extend the deadlines.

Source: Author provided

Just before the December 2017 deadline, the Union power ministry asked the government to extend the deadline to December 2019 for the NCR region and December 2022 for power plants in the rest of the country. It submitted a staggered implementation schedule prepared by the Central Electricity Authority (CEA).

The environment ministry accepted this proposal and, in an affidavit to the Supreme Court, submitted the CEA’s plan. However, it subsequently deviated from this commitment by amending the norms anew in 2021. This amendment pushed the deadline even further, without the Supreme Court’s explicit approval. It also set up a task force to classify thermal power plants into three categories based on certain parameters (see table 1 below).

Accordingly, all non-retiring thermal power plants were required to comply with the new rules at best by December 2024. So the deadline had in effect been pushed forward by two more years. Plants that fail to meet the revised deadline would have to pay a penalty.

In July 2021, in response to a Rajya Sabha question, the power ministry said:

“Environment compensation proposed to be levied on thermal power plants by Environment Ministry for non-compliance beyond the timelines will result in expeditious planning by thermal power plants for installation of sulphur regulator technology.”

However, this so-called threat of compensation proved futile. In September 2022, just a quarter before the charges would have come into force, the environment ministry modified the timeline yet again, pushing them further by two more years and revising the penalty.

The tables below show the latest compliance timelines for each category of thermal power plants and the compensation per unit of generation to be levied for non-compliance.

Pushing a deadline just as it approaches isn’t only inappropriate, it’s also legally untenable. Such a delay dilutes institutional credibility and negates any impact the proposed pecuniary deterrents could have had.

Further, coal and power shortages and fluctuations in short-term market prices of electricity could make it economical to run a non-compliant thermal power plant despite the penalty. So relying on a penalty to achieve compliance can in fact lead to a ‘pay and pollute’ culture.

In any case, it is also unclear whether the government will use the compensation collected to reduce impacts of air pollution, and if so, how. So in addition to financial penalties, the government also needs to consider more stringent measures, such as suspension of environment clearance until compliance is achieved.

There exists a parallel in India’s change from BS IV to BS VI fuel, which was possible because all stakeholders adhered to strict timelines and the concerned agencies were able to take concerted action. There is no reason why such a mechanism can’t be implemented for thermal power plants, whose emissions are of equal, if not greater, concern.

Also read: India’s Coal Power Plants Need Rs 86,135 Crore to Comply With Emission Standards: Study

Power sector’s role

Representative photo: Andrey Metelev/Unsplash

After the 2015 notification, some private power generators filed petitions before the Central Electricity Regulatory Commission (CERC) seeking to declare it a ‘change of law’ event. Such a declaration would have allowed the thermal power plants to recover the costs incurred on this account through a consumer tariff.

Though it was clear that the notification constituted a ‘change in law’ event, the power ministry declared this explicitly only in May 2018 – past the first deadline. As the ‘change in law’ was applicable to all thermal power plants, some thermal power plants had explicitly asked the CERC to create a country-wide mechanism for this purpose in 2016 itself!

The CERC sought the CEA’s advice, as the latter is responsible for specifying technical and safety standards for the construction, operation and maintenance of all electrical plants and equipment. The CEA took almost two years to publish a standard technical specification of FGD systems and to draft an implementation plan.

The initial deadline for compliance was well past at this point. In addition,  the CEA also questioned the need and effectiveness of FGDs for all thermal power plants and suggested delaying the deadline further than the 2021 amendment specified. This eventually came to pass with the September 2022 amendment to the rules.

The CERC – despite being the competent authority to decide whether an event could be considered a change in law under the power-purchase agreement – acted only after the power ministry issued a directive.

In contrast, in similar matters vis-à-vis coal price increase, the CERN had acted expeditiously and proactively to relieve thermal power plants in the form of a compensatory tariff. In fact, it had granted such a relief without being allowed by the electricity law or the power-purchase agreements.

Instead of creating a coherent country-wide mechanism to implement FGD, such regulatory decisions and delays have sown confusion and uncertainty.

An August 2020 judgement by the Appellate Tribunal for Electricity finally clarified the issue. The tribunal allowed plants to recover all prudent costs incurred towards compliance with the new norms.

The CERC and a few other state commissions had also made suitable provisions in their tariff regulations in 2019 to allow these costs.

Ultimately, in August 2021, the CERC issued a suo motu order formulating a mechanism to recover costs for all thermal power plants whose tariff was discovered through competitive bidding. India ultimately lost five years to ensure regulatory certainty for recovery of costs alone.

As a natural fallout of these delays and uncertainty, FGD implementation suffered. See the figure below for project-category-wise implementation status of existing thermal power plant capacity.


Source: CEA report, October 2022 

(Including capacity for which feasibility studies have started but haven’t been completed and capacity for which a feasibility study hasn’t yet been undertaken; including capacity under ‘tender specification made’, ‘NIT issued’ and ‘re-tendering’ stages; includes CFBC, SO2 compliant plants and units that are to be decommissioned or retired.)

Only 17% of category A projects have installed FGDs; none in category B and only 3% in category C have done so. As a result, the vast majority of thermal power plants are unlikely to comply even within the extended timeline.

Also read: Retrofitting Coal Power Plants With Carbon Capture May Lead To Increased Water Stress

Potential impact of FGD

Looking up a chimney at a coal power plant. Photo: Zoltan Tasi/Unsplash

A recent study published by the CEA and the Centre for Atmospheric Sciences at IIT Delhi analysed emissions and air quality at 240 stacks in 67 thermal power plants across the country. The main objective of the study was to evaluate the impact of FGD implementation on sulphur dioxide emissions.

Its most important finding was compelling evidence highlighting the benefits of FGDs. Specifically, it reported that these systems reduced sulphur dioxide emissions by 55% in a 60-80 km radius around the plant.

In 2020, the CEA had argued that the impact of sulphur dioxide emissions is not significant beyond 40 km, and had proposed prioritising FGD implementation only in critically polluted areas. The new study strikes down this idea.

It also noted that the conversion from sulphur dioxide to sulphate aerosols can occur even hundreds of kilometres from the source – and FGDs can significantly decrease (by about 30%) the surface concentrations of sulphate aerosols.

The Vindhyachal thermal power plant in Mirzapur, Uttar Pradesh, is located in a critically polluted region (it has the highest sulphur dioxide atmospheric column burden over India). Here, the effects of FGD were found to be phenomenal, reducing sulphur dioxide emissions by 83-85%.

However, despite its findings, the study also cautioned against implementing FGDs at all thermal power plants for some very curious reasons. It attempted to push the deadlines even further by proposing a staggered plan in which all thermal power plants would comply by 2034!

These concerns are not based on the data the study collected or analysed. They are addressed in detail below.

FDG technology is new in the Indian context” – FGD technology is neither new nor complex. It has been part of the thermal generation industry for many years. There is no dearth of experience and expertise in this area. Countries such as China and the US, which have many coal-based thermal power plants, installed FGDs decades ago and have reaped the contributions to air quality.

The study also records statements from Indian manufacturers, such as BHEL, which state: “Sufficient domestic manufacturing capacity exists in the nation for catering to current as well as future requirements of FGD implementation.” So there is no lack of technological expertise to ensure compliance.

Impact on foreign exchange – The study cited the impact on foreign exchange as a major concern. This is because some parts of FGD systems need to be imported. However, it failed to note that the power sector already relies heavily on imports.

Solar power plants in India import solar cells, modules and inverters. From April 2021 to January 2022, solar-cell imports cost India $3,447 million (approx. Rs 26,000 crore). Despite such a big bill, India has set itself a target of installing 280 GW of solar power capacity by 2030. The CEA has neither proposed delaying this capacity addition nor staggering it beyond 2030.

In contrast, FGD import costs are likely to be much lower. All thermal power plants are also guaranteed regulatory certainty to recover these costs. So there is no reason to delay implementation on these grounds.

Increased carbon dioxide emissions due to FGD implementation” – The study argued that since running an FGD system increases auxiliary consumption (by around 1%), it will also increase carbon dioxide emissions from thermal power plants.

This is theoretically correct – but overlooks the magnitude of increase in emissions due to FGDs. The argument also doesn’t propose any equally effective alternatives to control sulphur dioxide emissions. So it is difficult to take this concern seriously.

Using carbon dioxide emissions as an excuse to avoid an effective way to control sulphur dioxide emissions isn’t just inappropriate; it’s also deceitful.

Adverse impacts on global warming” – As noted earlier, sulphur dioxide emissions from thermal power plants are a major source of sulphate aerosols. Implementing FGDs at all thermal power plants can significantly reduce their concentration in the atmosphere.

The study claimed that such sudden and significant reduction in sulphate aerosols could accelerate the adverse impact of global warming – but without any evidence to substantiate such a serious claim. It then recommended delaying FGD implementation until all probable adverse effects were known.

This bizarre recommendation appeared even as the authors acknowledged that thermal power plants themselves were major contributors to global warming and climate change.

Power plants in the US and China, among others, have  had FGDs for many years now. To date they have never modified their emissions standards in this regard. This suggests that there is little reason, if any, to suspect that the  supposed impact is significant.

Water scarcity – The study suggests against implementing FGDs at thermal power plants in water-scarce regions. Running a TPP is an inherently water-intensive activity. The new norms also specify water consumption limits and mandate zero waste-water discharge for this very reason.

However, the study doesn’t exhort thermal power plants to comply with the new water consumption norms. Since running a plant requires much larger quantities of water, cutting FGDs’ water consumption is hardly going to help.

Not installing FGDs at such thermal power plants would mean continuing the status quo as far as air pollution is concerned. The solution should be to install FGDs and not run thermal power plants in water-scarce periods. Additionally, the government should diligently enforce strict adherence to water-consumption norms and then monitor for compliance.

Lifecycle cost and benefits – The study cited a lack of comprehensive lifecycle cost-benefit studies of FGD in India as a concern. This is bizarre. No such “comprehensive studies” were conducted before building new thermal power plants and setting up new coal mines, which obviously have much worse impact.

Such studies are undoubtedly useful and necessary, but they can’t be a precondition to install FGD systems. The correct starting point for this exercise should be for all existing and proposed thermal power plants and mining projects to install them.

Socioeconomic cost-benefit analysis – Raising yet another curious objection, the study pointed to the absence of a thorough socioeconomic cost-benefit analysis of FGD systems. It suggested that such analyses should be completed for existing FGDs and that their findings be evaluated before installing new FGDs at all thermal power plants.

The study failed to mention, however, that to date no such “thorough” exercise has been undertaken before approving new thermal power plants and coal-mining projects even though it is a prerequisite under the environmental impact assessment notification of 2006 and the Forest (Conservation) Act 1980.

The right place to commence these important practices would be when approving new thermal power plants and mining projects. FGDs are emission-control systems for thermal power plants, so the plant’s cost-benefit analysis will automatically include the corresponding analyses for its FGD system.

In sum, there is no merit to the concerns the IIT-CEA study has raised to further delay FGD implementation. Instead, it is extremely important and urgent to focus on its evidence-based findings and accelerate the installation of FGD systems at thermal power plants. If the authorities decide to go with its unsubstantiated concerns, however, it will be a travesty of both science and social and environmental justice.

Ashwini Chitnis is an independent researcher and policy analyst in Pune.

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