Chile: Generator Sets

National Emission Standards

National emissions limits for generator sets were established 2021.09 [5734]. These limits, Table 1 to Table 3, become effective from 2023.09 and are tightened for some engine categories from 2025.09.

Starting 2023.09, limits are based on EU Stage IIIA/EPA Tier 3 and Tier 2 nonroad, EPA Tier 2 marine and IMO Tier III standards. Staring 2025.09, limits for engines with rated power > 130 kW and engine displacement < 30 L/cylinder are tightened to those based on EU Stage IV/EPA Tier 4 nonroad and EPA Tier 4 marine standards.

Generator sets that operate in areas without access to the national grid and whose main use is to supply residential customers are exempted. The decree defines a new generator set as one that is imported after 24 months, and an existing generator set as one that was imported prior to 24 months from the entry into force of the decree.

**Table 1**
Emission limits for new generator sets with rated power below 560 kW
Date	Maximum Power	CO	NMHC	NMHC+NOx	NOx	PM
Date	kW	g/kWh
2023.09	19 ≤ P < 37	5.5	-	7.5	-	0.6
	37 ≤ P < 75	5	-	4.7	-	0.4
	75 ≤ P < 130	5	-	4	-	0.3
	130 ≤ P < 560	3.5	-	4	-	0.2
2025.09	130 ≤ P < 560	3.5	0.19	-	0.4	0.02

**Table 2**
Emission limits for new generator sets with rated power ≥ 560 kW and engine displacement < 30 L/cylinder
Date	Displacement	Maximum Power	CO	NMHC	NMHC+NOx	NOx	PM
Date	L/cyl.	kW	g/kWh
2023.09	d < 10	P ≥ 560	3.5	-	6.4	-	0.2
	10 ≤ d < 15	P ≥ 560	5	-	7.8	-	0.27
	15 ≤ d < 20	560 ≤ P < 3300	5	-	8.7	-	0.5
	15 ≤ d < 20	P ≥ 3300	5	-	9.8	-	0.5
	20 ≤ d < 25	P ≥ 560	5	-	9.8	-	0.5
	25 ≤ d < 30	P ≥ 560	5	-	11	-	0.5
2025.09	d < 10	P ≥ 560	3.5	0.19	-	0.67	0.03
	10 ≤ d < 30	560 ≤ P < 3700	5	-	1.8	-	0.04
	10 ≤ d < 30	P ≥ 3700	5	-	1.8	-	0.06

**Table 3**
Emission limits for new generator sets with rated power ≥ 560 kW and engine displacement ≥ 30 L/cylinder
Date	Max. Power	Max. Engine Speed	NOx	PM
Date	kW	rpm	g/kWh
2023.09	P ≥ 560	n < 130	3.4	0.15
		130 ≤ n < 2000	9 × n^-0.20
		2000 ≤ n	2.0

Santiago Metropolitan Region

Prior to the implantation of the national standards, generator set emissions for the Santiago Metropolitan Region were limited by regulations defining PM emission limits for stationary sources, Table 4. The limits applied to generator sets rated at 20 kW or more electrical output. Emissions were to be measured at rated conditions, converted to standard conditions (25°C and 1 atm) and corrected to 5% O₂ by volume.

**Table 4**
Emission limits for generator sets in the Santiago Metropolitan Region
Nominal Power, P	PM Limit	Application	Frequency of Certification
P < 300 kW	56 mg/Nm³	Continuous / Prime Power	Every 3 years
P < 300 kW	56 mg/Nm³	Emergency	Certification not required
P ≥ 300 kW	112 mg/Nm³	Continuous / Prime Power	Every 1 year
P ≥ 300 kW	112 mg/Nm³	Emergency	Certification required only once

In situations of poor ambient air quality, sources with PM emissions greater than 32 mg/Nm³ (28 mg/Nm³ if air quality is exceptionally bad) are not allowed to operate.

Prior to the national standard, several efforts to tighten the limits in the Santiago Metropolitan Region were made. For example, in November 2006, a draft regulation was published in Chile’s national gazette that would set emission limits in the Santiago Metropolitan Region for new and existing stand-by and emergency electricity generator sets of 20 kW or more electrical output, powered by internal combustion engines (Table 5). However, the final rule was never published and the proposal was abandoned. Efforts to implement EU Stage IIIA/EPA Tier 2 nonroad standards in the Santiago Metropolitan Region were also made in the mid-2010s.

**Table 5**
Proposed emission standards for generator sets in the Santiago Metropolitan Region, mg/Nm³
	Application	Nominal Power, P	PM	NOx	CO	THC
Existing Generators	Prime Power	20 kW ≤ P < 300 kW	45	5,000	600	400
	Prime Power	P ≥ 300 kW	5	5,000	600	400
	Emergency	P ≥ 150 kW	180	-	-	-
New Generators	Prime Power	20 kW ≤ P < 300 kW	45	2,900	600	400
	Prime Power	P ≥ 300 kW	5	2,900	600	400
	Emergency	P ≥ 20 kW	75	2,900	600	400