Air Quality Management 

Air pollutant emissions resulting from fuel combustion in thermal power generation such as nitrogen oxides (NO_X), sulfur dioxide (SO₂) and particulate matter (PM) can pose health risks and exacerbate climate change. These emissions are difficult to avoid entirely. Therefore, EGAT places great importance on air quality and pollution control to minimize health risks for stakeholders and preserve surrounding ecosystems. 

Targets for 2024	Performance Results
● Control key pollutant emissions (SO2, NOX and PM) to remain within regulatory limits.	● Key pollutant emissions were successfully controlled within target limits.
● Maintain the operational efficiency of Flue Gas Desulfurization (FGD) systems at all Mae Moh Power Plant units at no less than 93%.	● FGD systems at all Mae Moh units operated at the targeted efficiency.
● Apply Best Available Technology (BAT) to minimize emissions in all new projects from their Commercial Operation Date (COD) onwards (starting from 2019).	● BAT was implemented in all new projects with COD from 2019 onward, including: – Bang Pakong Combined Cycle Power Plant Unit 1 and South Bangkok Combined Cycle Power Plant Unit 4, which utilize nitrogen oxide (NOX) emission control systems through Dry Low NOX Burners when using natural gas as fuel and Water Injection systems when using diesel fuel.  – Mae Moh Thermal Power Plant Unit 14 which is equipped with a Flue Gas Desulfurization (FGD) system, Electrostatic Precipitator (ESP) for particulate matter control and nitrogen oxide emission control systems including Dry Low NOX Burners and Selective Catalytic Reduction (SCR).

Management

EGAT is firmly committed to managing and controlling air pollutant emissions from power plant stacks to ensure compliance with regulatory standards. This includes adherence to the Ministry of Industry’s Notification B.E. 2547 which stipulates permissible levels of air pollutants emitted from electricity generation facilities and the Ministry of Natural Resources and Environment’s Notification B.E. 2566 which sets emission standards for power plants. 

To minimize environmental impact and safeguard public health, EGAT monitors fine particulate matter (PM2.5) emissions from stack outlets, ensures the operational efficiency of Flue Gas Desulfurization (FGD) systems at all Mae Moh Power Plant units and applies Best Available Technology (BAT) to reduce emissions to the lowest feasible levels. 

A key component of EGAT’s air quality management strategy is the implementation of Continuous Emission Monitoring Systems (CEMS) which operate 24 hours a day to measure sulfur dioxide (SO₂), nitrogen oxides (NO_X) and particulate matter (PM). These systems ensure real-time compliance with legal requirements and help minimize environmental impacts. Monitoring results are continuously reported to the Department of Industrial Works and local communities through display screens, public notice boards at power plants and EGAT’s official websites. 

In addition to stack monitoring, EGAT operates Ambient Air Quality Monitoring Stations (AAQMS) around the clock and conducts biannual spot checks in surrounding communities. These efforts focus on measuring Total Suspended Particulates (TSP), PM-10, SO₂ and NO₂ using advanced instruments and technologies. The results are shared with local communities, and if any readings indicate potential risks, the monitoring system automatically alerts the power plant to initiate prompt corrective actions, ensuring timely environmental management. 

EGAT systematically collects air pollutant emission data to support ongoing environmental management efforts. This includes monitoring the concentrations of nitrogen oxides (NO_X), sulfur dioxide (SO₂) and particulate matter (PM) emitted from the stacks of eight EGAT-operated power plants. The collected data is used to calculate the total annual emissions (in tons) and the pollutant intensity, expressed as kilograms per megawatt-hour (kg/MWh) of net electricity output. 

To ensure accuracy and reliability, EGAT gathers actual operational data through two main components: 

1. Power Plant Service Hours and Gross Electricity Generation – This includes the total operating hours and the amount of electricity generated by each power plant. 
2. Pollutant Emission Quantity Data – This refers to the measured quantities of pollutants released into the atmosphere which are obtained through two methods: 
   • Continuous Emission Monitoring System (CEMS): Installed at the stack outlets, this system provides real-time, continuous measurements of actual emissions during plant operation. CEMS data is considered highly reliable as it reflects real-time operating conditions. Currently, Mae Moh Power Plant is the only facility utilizing CEMS data due to its completeness and readiness for use. 
   • Stack Sampling: Conducted twice annually, this method involves collecting emission samples from the stacks to represent annual pollutant levels. Measurements include concentrations of NO_X, SO₂, total PM, oxygen (O₂) and gas flow rate, taken during at least 80% of full-load operation. 

This comprehensive data collection approach enables EGAT to effectively monitor, analyze and manage air pollutant emissions, ensuring compliance with environmental standards and supporting its commitment to sustainable power generation. 

To ensure the accuracy of monitoring systems, EGAT verifies the performance of CEMS at all eight power plants twice a year. The organization also reports air quality performance to joint environmental monitoring committees including tripartite and subcommittees, and submits compliance reports to relevant government agencies every six months. 

Through these comprehensive measures, EGAT continues to uphold its commitment to environmental stewardship and public health protection. 

Air Pollutant Emissions from EGAT Power Plants 

Emissions	2024	2023	2022
SO2 Emissions (tonne)	13,239.06	15,153.05	15,862.27
SO2 Intensity (kg/MWh)	0.21	0.24	0.27
NOX Emissions (tonne)	33,594.63	37,689.27	33,264.62
NOX Intensity (kg/MWh)	0.54	0.60	0.57
PM Emissions (tonne)	709.51	787.87	616.03
PM Intensity (kg/MWh)	0.01	0.01	0.01

Note: The total electricity generation used for calculating SO₂ Intensity, NO_X Intensity, and PM Intensity is 61,953,338.07 megawatt-hours (MWh).