Eliminating coal-fired electricity in Ontario

In 2003, coal represented approximately 25%, or 7,560 MW, of Ontario's supply mix. In 2014, coal represented 0%, all while grid reliability and domestic supply improved.

The elimination of coal stands as the single largest greenhouse gas (GHG) emissions reduction action on the continent and was primarily responsible for Ontario achieving its 2014 emissions reduction target of 6% below 1990 levels.

The elimination of coal-fired electricity was a shared effort between the Ontario Ministry of Energy and two of its agencies:

  • Ontario Power Generation (OPG), the largest generator of electricity in the province, primarily through hydroelectric and nuclear sites
  • the Independent Electricity System Operator (IESO), whose duties include both procuring electricity supply and planning the electricity system over the long-term

The action plan

In 2001, Ontario had five coal-fired generating stations, comprised of 19 units totalling about 8,800 MW.

In 2003, Ontario committed to phase out coal-fired electricity entirely. That same year, the province announced that it would close Lakeview Generating Station (GS) (2,400 MW).

Ontario’s commitment to eliminate all of its coal-fired generation was enacted in a phased approach. Lakeview GS (2,400 MW) ceased operations in 2005, followed by Atikokan GS (211 MW) in 2012, Lambton GS (1,980 MW) and Nanticoke GS (3,940 MW) in 2013 and Thunder Bay GS (306 MW) in 2014.

The IESO was responsible for ensuring system reliability and sustainability during and following coal phase-out. A number of gas generators were built to replace much of the coal capacity that was phased out. These were operated through 2-3 peak seasons (summer and winter) and had to demonstrate consistent reliable performance before IESO allowed the controlled shutdown of the coal-fired generating fleet. Two nuclear units were also returned to service at the Bruce Nuclear Generating Station.

Bringing on large numbers of generators with a different fuel-type than coal posed new administrative and operational challenges to overcome:

  • establishing new processes for reporting and monitoring
  • enhancing new focus on gas-electric coordination
  • adapting to new operational characteristics such as ramp-up time.

Ontario enshrined its commitment in the Cessation of Coal Use Regulation (2007), which set an end date of December 31, 2014, and the Ending Coal for Cleaner Air Act (2015) which stipulates that coal cannot be used in future to generate electricity in Ontario.

The action plan timeline of events

  • 2001: Ontario announces that it will stop burning coal at Lakeview GS. Ontario appoints the Select Committee on Alternative Fuel Sources to make policy recommendations on alternative power sources.
  • 2003: Ontario announces the planned closure of the Lakeview Generating Station and commits to closing the province’s four remaining coal-fired power plants.
  • 2005: Lakeview GS Closes
  • 2006: Ministry of Energy instructs former Ontario Power Authority (OPA now IESO) to plan for coal phase-out at the earliest practical time, but still ensure adequate system capacity and reliability
  • 2007: Cessation of Coal Use Regulation directs end date of Dec. 31, 2014
  • 2012: Atikokan GS Closes
    Ending Coal for Cleaner Air Act is introduced
  • 2013: Nanticoke GS and Lambton GS Close
  • 2014: Thunder Bay GS Closes
  • 2015: Atikokan and Thunder Bay GS reopen, fueled by biomass
    Ending Coal for Cleaner Air Act is passed

Coal capacity was reduced in a staged approach from 2003-2014 to maintain system reliability and operational efficiency

Thunder Bay306306306306306306(April)

A new supply mix for Ontario (2003-2014)

Coal-fired electricity was replaced by a mix of baseload, intermittent and peaking capacity and a strong conservation and demand management approach

  • Nuclear: +1,500 MW
    Two units at Bruce Power were refurbished and returned to service in 2012.
  • Natural Gas: +5,500 MW
    The addition of new combined cycle facilities, a peaking plant and combined heat and power facilities.
  • Non-Hydro Renewables: +5,500 MW
    Added generation under procurements.

Percentage share of total generation 2003 and 2014footnote 1

Energy supplyPercentage of total generation 2003Percentage of total generation 2014
Non-hydro renewables0%7%

Post-coal energy planning

Ontario’s post-coal energy strategy is designed around five principles:

  • cost-effectiveness
  • reliability
  • clean energy
  • community engagement
  • conservation and demand management before building new generation

Ontario today

Approximately 94% of the electricity generated in Ontario in 2019 was emissions-free.

Nuclear energy provided approximately 61% of Ontario’s electricity generation, while hydroelectric stations provided approximately 25%.

Non-hydro renewables, such as wind, solar and bioenergy, provided approximately 7% of Ontario’s grid-connected electricity generation in 2019.

Benefits to Ontario

As a result of the phase-out of coal-fired electricity generation, Ontario has transformed its energy supply mix which has helped to decrease GHG, nitrogen oxides, sulphur dioxide and mercury emissions.

Electricity sector greenhouse gas emissions forecast (Megatonnes CO2e)

GHG Emissions32.927.530.926.417.219.614.812.

Nitrogen oxides, sulphur oxides and particulate matter emissions forecast (Tonnes)

PM 2.5178715291876131417792120562132418011613133011931205141315081538228822852356225722202024217221832359240024222376

The case for eliminating coal

The burning of coal for electricity generation is a significant source of GHG emissions, local and regional air pollution and mercury emissions.

The merits of eliminating coal-fired electricity include:


  • Increased North American natural gas supply has driven down prices, making gas-fired electricity more competitive.

The environment

  • Coal use is a major source of air pollutants, including nitrogen oxides (NOx), sulphur oxides (SOx), mercury and particulate matter (PM).
  • GHG reduction targets incent adoption of cleaner technology.

Keys to success

Ontario's success can be replicated in other jurisdictions while maintaining system reliability through the following principles:

  • build a broad implementation team: The Ministry of Energy worked with OPG and the IESO. OPG established a multi-disciplinary senior team consisting of Station Operations, Fuel Supply, Energy Planning & Forecasting, and Market Operations. The IESO procured electricity supply to maintain system reliability through long-term planning of the electricity system
  • manage your supply: OPG optimized coal inventories by developing a strategy on how to offer coal-fired electricity into the market. This strategy allowed for an adjustable rate of coal consumption to draw down the coal inventory in the lead up to closure dates
  • develop a long-term, coordinated plan including the conversion of existing infrastructure and overall supply-mix changes
  • keep the plan flexible in the event of a shift in supply/demand forecasts
  • consider how to mitigate cost increases in the sector (i.e., developing programs for industrial and residential consumers)
  • have a diverse supply mix to reduce reliance on any single supply source
  • take the time to get it right. Have a planned and staged approach to ensure system reliability
  • be prepared to develop new approaches to monitor and operate different forms of generation
  • incorporate Labour in the process: Obtain agreement with labour unions, ensuring operating staff are available on final day of operation. Scale staff throughout decommissioning and retain key roles throughout
  • communication planning is critical to anticipate and address issues from the public and stakeholders (e.g., price impact, system reliability and adequacy concerns)

Sharing Ontario’s lessons

Ontario can offer advice and guidance, thanks to its success in replacing coal-fired generation with a diverse mix of clean supply and demand management.

There is potential for OPG to partner with other jurisdictions looking to convert coal facilities to cleaner fuel types or build advanced biomass generating stations.

Appendix A

Supply mix as %
Province/StateYearCoalNatural Gas/OilNuclearHydroelectricNon-Hydro Renewables
New York2019N/A35.537.421.65.6
West Virginia201984.29.6N/A2.63.5

Ontario data source: IESO, 2018 Electricity Data
U.S. State data source: U.S. Energy Information Administration

Appendix B

2003 coal fleet details
Generating stationNumber of unitsFuel typeDelivery typeLocation
Atikokan1LigniteRailNorthwestern Ontario
Thunder Bay2Lignite / Northern Power River Basin BlendRail / VesselNorthwestern Ontario
Lambton42 Units (with scrubbers) – High Sulfur Coal
2 Units – Low Sulfur Coal
VesselSouthern Ontario
Nanticoke8Southern Powder River Basin / Low Sulfur BlendVesselSouthern Ontario
Lakeview4Low Sulfur CoalVesselSouthern Ontario

The schedule for phase-out was as follows:

  • Four Lakeview Units
  • Two Lambton Units (with low sulfur coal)
  • Four Nanticoke Units
  • Four Nanticoke Units
  • Two Lambton Units (with high sulfur coal) and 1 Atikokan Unit
  • Two Thunder Bay Units