Air Quality Management 

Air Pollutant Emission Monitoring System Weather Forecasting System

EGAT is committed to the careful and effective management of air pollutant emissions generated from fuel combustion in thermal power generation in order to minimize impacts on the health of stakeholders and surrounding ecosystems. 

2025 TargetsPerformance
● Control pollutant emissions to ensure compliance with the limits specified in the EIA/EHIA. ● Pollutant emissions remained within the limits specified in the EIA/EHIA. 
● Maintain the operating efficiency of the Flue Gas Desulfurization (FGD) systems at all generating units of the Mae Moh Power Plant at 93% or higher. ● The operating efficiency of the Flue Gas Desulfurization (FGD) systems at all generating units of the Mae Moh Power Plant was maintained at 93% or higher. 

Management Approach 

EGAT manages emissions from power plant stacks to ensure compliance with the control limits and standards prescribed in the Notification of Ministry of Industry, B.E. 2547 (2004) on the Amount of Air Contaminants Released from the Plant Which Generates, Transmits or Sell Electricity and the Notification of Ministry of Natural Resource and Environment, B.E. 2566 (2023) on the Standard for Control of Air Pollution Released from the Power Plant. EGAT also continuously monitors PM2.5 emissions from power plant stacks and maintains the operating efficiency of the sulfur dioxide removal systems (FGD) at all generating units of the Mae Moh Power Plant. Emphasis is placed on the adoption of the best available technology to minimize emissions, thereby reducing long-term impacts on the environment and public health in a sustainable manner. 

EGAT operates a Continuous Emission Monitoring System (CEMS) to monitor sulfur dioxide (SO₂), nitrogen oxides (NOₓ), and particulate matter (PM) from power plant stacks on a 24-hour continuous basis. This enables EGAT to control air quality from electricity generation processes in compliance with legal requirements and to minimize environmental impacts. Monitoring results are reported to the Department of Industrial Works and disclosed to surrounding communities through display screens, notice boards at plant entrances, and EGAT power plant websites. 

In addition, EGAT has installed Ambient Air Quality Monitoring Stations (AAQMS) that operate continuously, 24 hours a day, together with periodic monitoring conducted twice a year in communities surrounding the power plants to surveil and track ambient air quality. Parameters monitored include Total Suspended Particulates (TSP), particulate matter with a diameter of not more than 10 microns (PM10), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂), using modern equipment and technologies. The results are regularly communicated to communities. If monitoring results indicate the potential for adverse impacts on nearby communities, the system will issue an alert to the power plant so that corrective actions can be taken promptly and environmental quality can be managed in a timely manner.

To monitor operational performance, EGAT verifies the accuracy of the CEMS at all eight power plants twice a year to confirm the reliability and precision of the data. In addition, air quality performance results are reported to the joint committees for monitoring operations and community environmental development, including both the tripartite committees and tripartite subcommittees. EGAT also submits reports on compliance with environmental prevention and mitigation measures, as well as environmental impact monitoring measures, to government agencies and legally designated permitting authorities on a semi-annual basis. 

With regard to the management of coal dust, the Mae Moh Mine conducts assessments of air quality impacts arising from mining operations, including blasting, excavation or drilling, overburden and coal removal, and soil spreading, as specified in the Environmental Impact Assessment (EIA) report. Measures to mitigate air quality impacts include: 

  1. Dust mitigation measures in the mine pit and overburden disposal areas, such as increasing moisture at work sites, installing water spraying systems, using overburden conveyor systems, spraying water on roads, and improving road surfaces
  2. Dust mitigation measures at coal stockpile areas, such as installing water spray systems around the coal stockyard
  3. Measures to mitigate impacts from spontaneous coal combustion, such as compacting the surface of temporary coal piles and surveying hot spots before ignition occurs using infrared cameras

Air emissions from EGAT power plants
Emissions 202520242023
Sulfur dioxide (SO2) emissions (tonnes) 14,730.6013,239.0615,153.05
Sulfur dioxide (SO2) emission intensity (kg/MWh) 0.26 0.210.24
Nitrogen oxides (NOx) emissions (tonnes) 35,332.9333,594.6337,689.27
Nitrogen oxides (NOx) emission intensity (kg/MWh) 0.620.540.60
Particulate matter (PM) emissions (tonnes) 718.94709.51787.87
Particulate matter (PM) emission intensity (kg/MWh) 0.010.010.01

Notes 
1. Power plant service hours and gross electricity generation data.
2. Pollutant emission quantity data are collected using two methods:
          2.1 Data collection from the Continuous Emissions Monitoring System (CEMS) at power plant stacks. These values are more reliable than those obtained through other sampling methods because they are collected under actual operating conditions. Mae Moh Power Plant is the only EGAT power plant using CEMS data because the data are complete and available for use.
          2.2 Data collection through stack sampling, which measures actual pollutant emissions from power plant stacks twice a year and is used as representative data for annual pollutant emissions. Data are collected at an operating load of at least 80% of full load.
3. Total electricity generation used to calculate SO2, NOx and PM emission intensity was 56,867,608.89 MWh.