Air pollutant emissions from electric utilities

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Electricity generation produces a large share of total national sulphur oxides (SOX) and nitrogen oxides (NOX). Sulphur oxides and NOX are mostly emitted from power plants burning fossil fuels such as coal and, to a lesser extent, natural gas and diesel. These air pollutants are responsible for the formation of fine particulate matter, ozone, smog and acid rain. They also adversely affect human health and the economy.

Key results

  • In 2015, electric utilities were the source of 24% and 8% of total Canadian emissions of SOX and NOX.
  • Most of the air pollutant emissions from electric utilities come from burning coal.
  • Electric utilities are also a source of carbon monoxide (CO), volatile organic compounds (VOCs), fine particulate matter (PM2.5) and ammonia (NH3) emissions. However, they account for less than 1% of the total national emissions of these pollutants.

Contribution of electric utilities to national air pollutant emissions by fuel source, Canada, 2015

Stacked column chart showing contribution of electric utilities to national air pollutant emissions by fuel source. Long description below.

Long description

The stacked column chart shows the contribution in percent of electric utilities to total national emissions of sulphur oxides and nitrogen oxides in 2015 in Canada by fuel source: coal, natural gas, diesel and other.

Data for this chart
Contribution of electric utilities to national air pollutant emissions by fuel source, Canada, 2015
Fuel sourceSulphur oxides (percentage of national emissions)Nitrogen oxides (percentage of national emissions)Carbon monoxide (percentage of national emissions)Fine particulate matter (percentage of national emissions)Volatile organic compounds (percentage of national emissions)Ammonia (percentage of national emissions)
Coal22.96.10.30.2<0.1<0.1
Natural gas0.20.90.2<0.1<0.1<0.1
Diesel<0.10.5<0.1<0.10<0.1
Other0.70.60.1<0.1<0.1<0.1
Emissions of air pollutants from electric utilities by fuel source, Canada, 2015
Fuel sourceSulphur oxides (kilotonnes)Nitrogen oxides (kilotonnes)Carbon monoxide (kilotonnes)Fine particulate matter (kilotonnes)Volatile organic compounds (kilotonnes)Ammonia (kilotonnes)
Coal242115163< 1< 1
Natural gas21614< 11< 1
Diesel< 191< 1< 1< 1
Other8128< 11< 1

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How this indicator was calculated

Note: Carbon monoxide, fine particulate matter, volatile organic compounds and ammonia are not shown in the chart due to their low share (≤ 1%) of total emissions in 2015. Excludes emissions from industries that generate electricity and heat as a supporting activity rather than as their primary purpose. "Other" fuel sources include waste material and other uncategorized sources of electricity generation.
Source: Environment and Climate Change Canada (2017) Air Pollutant Emission Inventory.

More information

In 2015, 96% of SOX and 76% of NOX emissions from electric utilities came from burning coal.

While generating electricity by burning fossil fuels causes air pollutant emissions, the use of non-fossil energy sources, such as hydro-electricity, nuclear power and other renewable sources to generate electricity does not emit air pollutants. A large share of the electricity generated in Canada comes from sources that do not emit air pollutants:

  • 59% of electricity comes from hydro
  • 16% comes from nuclear power plants
  • 5% comes from non-hydro renewable sources, such as wind, solar, tidal power and biomassFootnote [1]

Changes in emissions from electric utilities

Key results

  • Emissions of SOX and NOX from electric utilities declined by 59% and 40%, respectively, between 1990 and 2015.
  • Most of that decline occurred from 2005 onward.

Changes in emissions of key air pollutants from electric utilities, Canada, 1990 to 2015

Line chart showing the changes in emissions of key air pollutants from electric utilities. Long description below.

Long description

The indexed line chart shows emissions changes from 1990 to 2015, as a percent of 1990 emissions, for 2 air pollutants from electric utilities: nitrogen oxides and sulphur oxides.

Data for this chart
Changes in emissions of key air pollutants from electric utilities, Canada, 1990 to 2015
YearNitrogen oxides (emissions changes as a percentage of 1990 levels)Sulphur oxides (emissions changes as a percentage of 1990 levels)
199000
1991-2-4
19922-1
1993-6-12
1994-8-9
1995-4-14
19965-12
199712-4
199819-2
199918-3
2000210
2001171
2002180
2003123
20041-10
2005-3-15
2006-11-26
2007-6-20
2008-11-31
2009-14-38
2010-8-46
2011-21-53
2012-34-54
2013-36-55
2014-34-56
2015-40-59
Emissions of key air pollutants from electric utilities, Canada, 1990 to 2015
YearNitrogen oxides (kilotonnes)Sulphur oxides (kilotonnes)
1990253618
1991248592
1992258611
1993237547
1994233560
1995244533
1996265542
1997282591
1998302604
1999298601
2000308619
2001296624
2002300616
2003284635
2004256559
2005246526
2006225459
2007239492
2008225428
2009218384
2010234334
2011200293
2012166284
2013162278
2014167269
2015152252

Download data file (Excel/CSV; 1.42 KB)

How this indicator was calculated

Note: Carbon monoxide, fine particulate matter, volatile organic compounds and ammonia are not shown in the chart due to their low share (≤ 1%) of total emissions in 2015. Excludes emissions from industries that generate electricity and heat as a supporting activity rather than as their primary purpose.
Source: Environment and Climate Change Canada (2017) Air Pollutant Emission Inventory.

More information

Between 2005 and 2015, emissions of NOX and SOX decreased by 38% and 52%, respectively. Over the same period, the share of electricity that came from burning fossil fuels fell from 25% to 19%. This decline was mostly the result of a gradual drop in electricity generation from coal power plants.Footnote [2]

The emissions reductions since 2005 are mainly due to:

  • the change in the mix of energy sources used to generate electricity
  • the introduction of regulations
  • domestic and international agreements
  • better removal technologies
  • plant closures

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