New Environmental norms for Thermal Power Plants: Challenge’s

29 Jan 2023

INTRODUCTION:

Coal is central to India’s energy needs. It contributes around 75 per cent of India’s current electricity generation and, according to NITI Aayog projections, will remain the dominant source of power for the next couple of decades. Coal is abundantly available and provides a reliable, cheap baseload power. But the coal-based thermal power industry is responsible for a significant share of emissions of the industrial sector in India and it therefore has an outsized impact on air pollution.  Cleaning the sector will have vast benefits for the environment and on human health.

In continuing efforts to safeguard the environment and reduce emissions from power sector, India has made the commitments to reduce the emissions intensity of its GDP by 33 to 35 % by 2030 from 2005 level and to achieve about 40 percent cumulative electric power installed capacity from non-fossil fuel based energy resources by 2030 with the help of transfer of technology and low cost international finance.  India also committed for introducing new, more efficient and cleaner technologies in thermal power generation.

Recognizing the central role, thermal power plays in worsening air quality, the Ministry ofEnvironment, Forest & Climate Change (MoEF&CC) announced in December’ 2015 tighter standards for coal-based thermal power plants. In order to reduce emissions from Thermal Power Stations, Ministry of Environment, Forest and Climate Change has issued new environmental norms in December’ 2015 regarding Suspended Particulate matter (SPM), SOx, NOx and Mercury. Norms for specific water consumption by Thermal Power Stations have also been notified by the government to conserve water.

The present installed capacity of coal based thermal power plants is 1,94,445 MW as on 31.05.2019 and approximately 40 GW is under construction which is likely to be affected by the new norms. The Ministry of Environment, Forest & Climate Change has notified the revised standards for coal-based Thermal Power Plants in the country, with the primary aim of minimising pollution. The new standards aim to drastically cut emissions of particulate matter (PM), sulphur dioxide (SO2), oxides of nitrogen (NOx) and mercury. In addition, the new norms also require power plants to sharply curtail freshwater use. These standards are proposed to be implemented in a phased manner. In order to implement new norms, the thermal power plants are categorised into 3 categories, namely those:- (i) Installed before 31^st December, 2003 (ii) Installed after 2003 upto 31^st December, 2016 and (iii) Installed after 31^st December, 2016.

The new standards are aimed at reducing emission of PM10 (0.98 kg/MWh), sulphur dioxide (7.3 Kg/MWh) and Oxide of nitrogen (4.8 kg/MWh), which will in turn help in bringing about an improvement in the Ambient Air Quality (AAQ) in and around thermal power plants. The technology employed for the control of the proposed limit of Sulfur Dioxide - SO2 & Nitrogen Oxide - NOx will also help in control of mercury emission (at about 70-90%) as a co-benefit. Limiting the use of water in thermal power plant will lead to water conservation (about 1.5 M³/MWh) as thermal power plant is a water-intensive industry. This will also lead to a reduction in energy requirement for drawl of water. With regard to implementation of water norms, the thermal power plants are categorised into following three categories:

• All plants with Once Through Cooling (OTC) shall install Cooling Tower (CT) and achieve specific water consumption of 3.5 m3/MWh within 2 years of notification.
• All existing CT based plants shall reduce specific water consumption up-to maximum of 3.5 m3/MWh within a period of 2 years of notification.
• New plants to be installed after 1st January 2017 shall have to meet specific water consumption of 2.5 m3/MWh and achieve zero water discharge.

The standards have been made stringent for recent plants, compared to earlier ones and most stringent for those plants to be set up in future. These standards are based on the recommendation of the Central Pollution Control Board (CPCB) after consultations with stakeholders. The above norms were compiled within two years from the notification by the existing thermal power stations and from 1.1.2017 by the plants under construction. From 2017, thermal power plants across India will have to cut particulate matter emissions by as much as 40 per cent and reduce their water consumption by nearly a third according to this notification. The timeline has now extended by March’ 2021.

OTHER STATUTORY PROVISIONS:

The Electricity Act 2003 envisages a strong push to the promotion of efficient and environmentally benign policies, thrust on rural electrification and stronger provisions for punishment for not following the environment norms. Section 67(2) of the Act empower the appropriate Government to frame rules for power companies to specify the avoidance of public nuisance, environmental damage and unnecessary damage to the public and private property by such works. The National Electricity Policy and the Tariff Policy further provide guidelines for the development and operation of the Power Sector within the ambit of the Electricity Act.

The new National Tariff Policy notified by the Central Government on 28^th January, 2016 also look to strengthen regulatory mechanism so that power companies become more efficient and conscious towards their duties to environmental protection. The new tariff policy is focus on clean energy, and has a challenge to add 1.75 Lakh MW of renewable energy. It also includes the elements, which will promote Swachh Bharat Abhiyan and help waste to energy, prosper in India. Under the policy, the power plants will have to use processed municipal waste water available in their vicinity (in 100 km radius). It will allow distribution companies to buy any amount of power produced from the waste.  The new policy reflects a concern to environment and encourages renewable energy. Several unique aspects which have not been touched in the past are being brought out in this policy. The new tariff policy will give a big push to electricity generated from renewable energy sources and address concerns related to the environment. To release clean water to meet drinking water needs of cities and reduce pollution of rivers, it will be mandatory for thermal power plants within specified area of sewage treatment facilities to use treated sewage water.

NEED OF TIGHTEN ENVIRONMENTAL NORMS:

With a view to reduce Green House Gas emission, harnessing of renewable resources to the extent possible, promotion of hydro and nuclear generation, enhancing efficiency of the existing power plants and introduction of new technologies for power generation for enhancing efficiency and demand side management are being pursued. Since coal will continue to dominate power generation in future, Super Critical Technology has been introduced for reduction of green-house gases. Government of India has taken a number of Initiatives to adopt a more pro-active, market-oriented approach to rid the Power Sector and problems being faced by it. These range from changing the structure of the Power Utilities to the operating environment and the Legislative and Regulatory framework governing the Power Sector. Most significant changes have been the unbundling of the vertically integrated business of generation, transmission & distribution and the entry of private sector in power generation, transmission & distribution. These Initiatives are expected to set the stage for a quantum jump in the capacity addition programme considering environmental issues and also making clean electricity available to all includes rural households.

NEW STANDARDS RATIONALE:

MoEF&CC has given a tight albeit achievable deadline to meet the new standards. Existing plants were given two years from the notification whereas the plants commissioned after 1^st January 2017 were to comply from the start of their operations. The timeline has now been extended till March’ 2021. The limit of different parameters are as given below:

Standards (in mg/Nm3)

The new standards were based on CPCB and MoEF&CC’s extensive consultations with experts and industry studies. The norms considered a range of factors like age and size of the units and available pollution control technologies. CPCB analysed reported data emissions of all plants 

report PM and several plants also tracked SOx and NOx emissions to assess norms that are achievable. Norms in other major countries, including China, provided a peer benchmark. Environmental clearances given since 2003 required units larger than 500 MW to keep space for future installation of flue gas desulphurization (FGD); therefore space availability isn’t an issue for these units. Also, Environmental clearances after 2008 required plants to meet PM of 50 mg/Nm3, which means that plants that became operational after 2008 should be able to meet this standard.

The power sector had itself agreed to improve its environmental performance under the voluntary 2003 under the Corporate Responsibility for Environmental Protection (CREPS), which included meeting tighter PM emissions standards (100 mg/Nm3) and implementing SOx/NOx standards by 2005–06. The sector failed to act on its voluntary commitment. In fact, a study revealed that almost two thirds of coal-based thermal power plants failed to comply with even the prevailing loose standards.

FINANCIAL IMPLECATIONS:

The technology availability or suitability for Indian coal was not the impediment-electrostatic precipitators (ESPs) can be augmented to achieve norms; flue gas desulphurization (FGD), to control SOx, is a mature technology; suppliers are confident that Selective Catalyst Reduction (SCR) technology will work for Indian coal to control NOx. The exact investment needed by a plant would depend on the combination of upgradation and new installation required, which in turn would depend on existing abatement technology, actual emissions, applicable norms and age of the plant. Based on the projected capital expenditures given by the plants, the State Electricity Regulatory Commission estimated a generation tariff impact of around 22 to 25 paisa per unit. Estimated Cost of pollution-control technologyfor controlling the different environmental parameters are given below:

However, some legitimate concerns need to be addressed. Commercial issues like financing for the investment required and cost recovery through tariff increase remain unresolved. Therefore, concerted action steps from all policymakers/regulators and various Electricity Regulatory Commissions, Central Electricity Authority (CEA)/Ministry of Power (MoP) and MoEF&CC/Central Pollution Control Board are critical to achieve timely implementation. Equipment installation can be done during scheduled shut down or may need less than one month of shut down. However, procurement and installation of FGD could take up to 24 months. Additional time may now be needed for some plants. Plants under construction need to change construction plans and procure equipment to meet the new norms within timeline, which would be a challenge.

UTILIZATION OF FLY ASH:

The Extra Ordinary Gazette Notification issued by Government of India, Ministry of Environment and Forest dated 3^rd November 2009 in regard to the amendments made in the Environment (Protectionn) Act, 1986 and The Environment (Protection) Rules,1986, provides for mandatory directives for utilization of Fly Ash generated at the Thermal Power Plants. It provides that the amount collected from sale of fly ash and fly ash based products by coal and/or lignite based thermal power stations or their subsidiary or sister concern unit, as applicable should be kept in a separate account head and shall be utilized only for development of infrastructure or facilities, promotion and facilitation activities for use of fly ash until 100% fly ash utilization level is achieved ; thereafter as long as 100% fly ash utilization levels are maintained , the thermal power station would be free to utilize the amount collected for other development programmes also and in case, there is a reduction in the fly ash utilization levels in the subsequent year(s), the use of financial returns from fly ash shall get restricted to development of infrastructure or facilities and promotion or facilitation activities for fly ash utilization until 100% fly ash utilization level is again achieved and maintained.

POLLUTION-CONTROL TECHNOLOGY

Many large-scale manufacturers, including BHEL, Mitsubishi and GE-Alstom, have strongly emphasized that pollution control technologies options are widely available and can easily meet even the tightest standards that have been proposed. An overview of various options based on the size and vintage of units, required emission levels that need to be achieved, indicative range of investment needed and installation time required. The two most important parameters to decide what pollution-control options are most appropriate are age and size of the unit.

Investments in plants/units that have exceeded their design life of 25 years (34.1 GW capacity) must be made carefully considering their efficiency and availability. Most of them should probably be expeditiously shut. Basic upgradation targeting mainly PM control may, however, suffice in the interim. This relaxation must be accompanied by a clear plan to decommission units and, in a few cases, replace them with new supercritical units. Units with good operating performance, low cost of generation and recent R&M that has extended remaining life may be allowed to invest so they can meet the new standards.

1. Particulate matter (PM)

 Units commissioned between 1990 and 2008 (43.0 GW total capacity) may need to upgrade the ESP to meet the PM norms of 100 and 50 mg/Nm3. In some cases, it may involve adding fields in series or parallel or increasing the height of ESP. The cost of these renovations would be around Rs 15 lakh/MW.   The units installed after 2008 (109.4 GW capacity) were required to meet PM norms of 50 mg/Nm3 by the environment clearances. Therefore, a basic performance revamp may suffice for these units. However, some units were required to meet 100–150 mg/Nm3 and others are poorly performing an investment of at most Rs 10 lakh/MW may be required for these units.  Units in pipeline should be able to meet the 30 mg/Nm3 PM standard with a combination of ESP and FGD. In fact, an integrated design would mean that the ESP size can be made smaller than a standalone one for meeting the norm.

1. Sulphur dioxide (SO₂)

FGD is a mature technology for controlling SOx. It is used in many countries and has been shown to be effective for a wide range of coal qualities and operating conditions. China has installed FGD in over 91.4 per cent of its fleet in recent years. Limestone is the key raw material required for FGD. Based on the assumption that only units larger than 500 MW will install FGD and smaller units can install partial FGD, around 10–12 million tonnes of limestone is required, which is a small fraction of cement industry’s limestone use. Moreover, gypsum (byproduct) produced by the wet FGD process can be used by the construction industry 

 Units of size less than 500 MW installed between 1990 and 2016 (54.2 GW capacity) need to meet the SOx norm of 600 mg/Nm3. These units may choose economical options such as partial FGD or sorbent injection. The cost is estimated to be around Rs 25–30 lakh/MW (assuming FGD for half the plant capacity). Units of size 500 MW and more, installed between 1990 and 2016 (98.3 GW capacity), have to install limestone-based wet FGD or lime-based dry FGD, depending on raw material and water availability. The costs are estimated to be Rs 50–60 lakh/MW.

1. Oxides of nitrogen (NOx)

 Minimal measures are needed to meet emissions of less than 600 mg/Nm3 for the 31.1 GW of capacity installed between 1990 and 2003 on a case-to-case basis. Some units are already meeting these levels, according to data reported by the plants to CPCB it is conservatively estimated an investment of Rs 10 lakh per MW.

 A capacity of 121.3 GW that was installed after 2003 has to reduce emissions to 300 mg/ Nm3. According to CPCB, some plants are already meeting these values. Manufacturers, including BHEL, have already been supplying boilers that meet these emissions. Those plants whose emissions exceed the norms will need to choose from several options including burner modification, over fire air supply (OFA) etc., depending on the base level of emissions and technical constraints. The costs for these upgrades will be around Rs 10–15 lakh/MW. In rare cases, plants may need to instal SNCR or SCR. These would cost Rs 20–25 lakh/MW. Upcoming units need to meet the NOx emissions of 100 mg/Nm3. SCR and SNCR technologies have been used globally to cut NOx to these levels. Some industry players, however, feel that the technology’s effectiveness needs to be established for Indian coal (high ash, chemical composition and physical characteristics).

An existing plant would obviously not require all pollution-control equipment to be installed. For example, many new plants, installed after 2008, may not require to do anything for PM and NOx control. The exact investment required by a plant would depend upon a number of factors like age, size and technology of units; currently installed pollution-control equipment and their maintenance status; actual emissions; and applicable norms. The De-NOx process will require ammonia or urea particularly for new plants. Currently, both are imported. The annual requirement for ammonia is estimated to be 5 million tonne and for urea 7 million tonnes.

Major Technical Issues

The little progress has been made towards the implementation of new standards. The plants raised several issues for not making sufficient progress. Many plants have insufficient knowledge or experience of advanced pollution control technologies. Plants expressed concern that the pollution control technologies were unsuitable for high-ash Indian coal and manufacturer capacity is insufficient to meet the projected demand; some think space for the installation of pollution control equipment’s and storage of raw material would be a constraint. Most plants believed that the costs to install pollution control equipment were high with little clarity on cost recovery. They also felt the timelines were tight.

1. Suspended Particulate Matter- Retro-fitting of additional fields in ESP/ replacement of ESP etc. required to achieve the proposed norms in existing plants. There may be space constraints in modification in ESP area in the existing plants. A capacity of around 60 GW (302 Units) may have such space problems while retrofitting equipment to meet revised environmental norms.
2. Sulphur Dioxide (SOx)- FGD system would need to be installed to meet the amended norms regarding SOx control for all categories of existing plants as well as plants under construction. The Units of less than 500 MW size and some older 500 MW units face layout problems for installation of FGD system due to non-availability of space. A capacity of around 90 GW (430 units) is facing problem due to non-availability of space for FGD. A capacity of around 90 GW (151 units) of existing plants and 72 GW (73 units) of plants under construction would require installation of FGD plant.
3. Oxides of Nitrogen (NOx)- The proposed standards of 600 mg/Nm3 (302 existing units) would require modification of the combustion process using low NOx burners. The proposed standards of 300 mg/Nm3 and 100 mg/Nm3 would require installation of de-nitrification systems like Selective Catalytic Reduction (SCR) systems. Layout issues for installation of DeNOx system in the existing units. The globally available SCR system for NOx control are not proven for Indian coal having high ash contents. A capacity of around 120 GW (279 units) of existing plants and 72 GW (73 units) of under construction plants may require installation of SCR systems to meet new norms.
4. Financial Issue– Financing for investment required to meet the norms remains one of the main concerns—the investment required and its impact on cost of generation. Uncertainty over the recoverability of cost and time taken for tariff approval were additional concerns. This issue is exacerbated by the weak financial health of discoms which, in turn, has already affected the power generators.

Recommendations:

1. MoEF should survey the implementation status of power plants to assess compliance with the new norms and develop a revised schedule. Revision of timelines should be on a case-by-case basis backed by strong commitments, clear evidence of progress and bank guarantees.
2. Plants under construction should meet the standards on the commissioning date since modification at a later may be disruptive; however, retrofitting to meet the norms within the next one to two years may be permitted if there are techno-economic benefits. Plants with firm retirement or replacement plans may be allowed to operate in the interim.
3. CEA should act as the key technical advisor and prepare a ‘Technology Guidelines’ document that details technological options to control pollutants, their suitability for Indian coal, life cycle and O&M costs. Capital cost benchmarking for the options should be done. Work that has already been done by industry leaders, such as NTPC can be used.
4. CERC should prepare a simplified tariff application for in-principle capital expenditure (capex) and preliminary tariff approval that should also be used by state regulators. ERCs should ask plants to urgently provide unit-wise assessment of capex required and tariff impact.
5. CERC could consider uniform tariff increases based on minimum capital costs that are in accordance with CEA guidance. (Final tariff approvals can be modified to account for approved costs.) The tariff increases could be staggered to make them acceptable to discoms/consumers.
6. CEA and CPCB should develop a monitoring mechanism and regularly track the progress made by individual plants in installing equipment. The quarterly progress report should be made available in the public domain.
7. CEA and POSOCO need to prepare a scheduled shut-down plan for the entire fleet for         installation of pollution control equipment to avoid supply disruption.
8. Government should divert a portion of National Clean Energy Fund (NCEF)—a coal cess would be recovered from the power sector to support installation of pollution control equipment. Support could come in the form of subsidized loans, credit enhancement or even equity component of the investment required.
9. The government should work on an expedited plan to retire or replace old capacity based on operating and environmental performance and incremental investment required to comply with new norms. Incentives should be given for replacing the units with SC units— for e.g., they may not need Environmental Clearances (ECs). New investors can be encouraged to come in by giving them coal linkages and PPAs associated with the old plants.
10. Incentives should be considered for plants that meet norms by the deadline. For e.g. ‘merit order dispatch’ preference could be given to these plants.
11. Requirement to arrive at an understanding of various technology solutions to meet new standards and address issues of suitability for Indian coal, cost and supplier capacity.
12. To short out regulatory bottlenecks (tariff increase and capital investment approvals) and financial issues, discuss cost recovery and financial support ideas. To understand any other issues, such as supplier capacity, raw material availability, waste management etc.  The power regulators devise a monitoring and enforcement plan.

CONCLUSION:

Government has notified the key performance standards for power stations to ensure environmental protection. The government yet to take concrete steps to actually implement these standards due to lack of resources that might assist in performing their functions- most notably, enough professional staff and appropriate information technology systems. In order to maintain the revised environmental norms, the government is required to develop a strong monitoring mechanism and strengthen the regulatory bodies to monitor these norms. For maintaining the revised environmental norms, substantial capital investment needs to be required by the power companies. The regulators are required to take care in this regard.