How We Make Electricity

How We Make Electricity


We make electricity from a variety of sources. Our use of coal in generating electricity has declined significantly in recent years, thanks to the use of more wind power and natural gas. Learn more about each type:

coal petcokenatural gas hydro&tidal wind biomass fuel oil


Coal

For many years, coal has supplied most of Nova Scotia’s electricity. Until 1999, our plants were supplied with coal mined in Nova Scotia, utilizing what was a local and economic resource. Most of the coal we use is sourced from international markets but we purchase domestic coal if it is available, meets environmental requirements, and is competitively priced.

Nova Scotia has the most aggressive greenhouse gas regulations in Canada, requiring a 25% reduction in emissions over the 2010 to 2020 period. The federal government has agreed to let Nova Scotia’s regulations take precedence over proposed national rules, provided that provincial rules achieve the same environmental benefit. This will save Nova Scotians hundreds of millions of dollars by allowing us to close coal units when it is most advantageous to our customers, not simply based on age, as the federal rules would have required.


LINGAN GENERATING STATION
Generating Capacity620 MW
LocationLingan, Cape Breton Island
  • Constructed in the 1970s, Lingan's four units were commissioned separately from 1979-1983. Lingan is Nova Scotia Power’s largest generating station. 

  • ‘Low-NOx’ combustion systems were installed from 2006 to 2008 on all four units. The systems help prevent the creation of nitrogen oxides with a resulting reduction in NOx emissions of about 40 per cent.

  • In 2012 Nova Scotia Power announced that two of Lingan's units would be operated only on a seasonal basis due to decreased industrial load, increased renewable energy use and to meet environmental requirements.
 


POINT ACONI GENERATING STATION
Generating Capacity171 MW
LocationPoint Aconi, Cape Breton Island
Due to its design, Point Aconi is primarily fueled by petcoke, which is a solid by-product of the oil refining process.

  • The plant’s circulating fluidized bed technology means it can use petcoke in its boiler while significantly reducing emissions. Petcoke has a high heating value compared to coal and is usually lower cost than coal, but it also has a higher sulphur content. Point Aconi has a 90 per cent reduction of sulphur dioxide emissions and lower nitrogen oxide emissions than typical coal boilers because of its special boiler technology.

  • Point Aconi has greater fuel flexibility than the other three coal plants because the exhaust flue gas that comes out of the boiler goes into a baghouse that filters particulate emissions.
 

POINT TUPPER GENERATING STATION
Generating Capacity154 MW
LocationPoint Tupper, Cape Breton Island
  • Point Tupper Generating Station was commissioned as an oil-burning unit in 1973. It was converted to coal and recommissioned in 1987. 

  • A ‘Low-NOx’ combustion firing system was installed in 2008 to prevent the creation of nitrogen oxides.

  • The main boiler exhausts flue gas through its own electrostatic precipitator designed to capture 99 per cent of fly ash emissions.
 

TRENTON GENERATING STATION
Generating Capacity307 MW
LocationTrenton, Nova Scotia
  • Trenton Unit 5 was commissioned in 1969 and underwent a multi-million dollar complete refurbishment in 2009, leading to improved efficiency of the unit. 

  • he refurbishment at Unit 5 included a new generator and a ‘baghouse,’ a technology that acts as a large filter for the plant’s emissions. It significantly reduces fly ash emissions and allows the plant to have greater fuel flexibility. 

  • Trenton Unit 6 was commissioned in 1991 and was modified with a ‘Low-NOx’ combustion firing system in 2008 to prevent the creation of nitrogen oxides. 

  • Both Trenton units have electrostatic precipitators designed to capture 99 per cent of fly ash emissions from coal burning. 
 

Petcoke

We buy petcoke when doing so will save money for customers compared to other fossil fuels. It has higher carbon dioxide and sulphur dioxide emissions than coal, but lower mercury. We mostly use it at the Point Aconi generating station, which has special equipment that captures 90% of the sulphur.

LINGAN GENERATING STATION
Generating Capacity620 MW
LocationLingan, Cape Breton Island
  • Constructed in the 1970s, Lingan's four units were commissioned separately from 1979-1983. Lingan is Nova Scotia Power’s largest generating station. 

  • ‘Low-NOx’ combustion systems were installed from 2006 to 2008 on all four units. The systems help prevent the creation of nitrogen oxides with a resulting reduction in NOx emissions of about 40 per cent.

  • In 2012 Nova Scotia Power announced that two of Lingan's units would be operated only on a seasonal basis due to decreased industrial load, increased renewable energy use and to meet environmental requirements.
 


POINT ACONI GENERATING STATION
Generating Capacity171 MW
LocationPoint Aconi, Cape Breton Island
Due to its design, Point Aconi is primarily fueled by petcoke, which is a solid by-product of the oil refining process.

  • The plant’s circulating fluidized bed technology means it can use petcoke in its boiler while significantly reducing emissions. Petcoke has a high heating value compared to coal and is usually lower cost than coal, but it also has a higher sulphur content. Point Aconi has a 90 per cent reduction of sulphur dioxide emissions and lower nitrogen oxide emissions than typical coal boilers because of its special boiler technology.

  • Point Aconi has greater fuel flexibility than the other three coal plants because the exhaust flue gas that comes out of the boiler goes into a baghouse that filters particulate emissions.
 


POINT TUPPER GENERATING STATION
Generating Capacity154 MW
LocationPoint Tupper, Cape Breton Island
  • Point Tupper Generating Station was commissioned as an oil-burning unit in 1973. It was converted to coal and recommissioned in 1987. 

  • A ‘Low-NOx’ combustion firing system was installed in 2008 to prevent the creation of nitrogen oxides.

  • The main boiler exhausts flue gas through its own electrostatic precipitator designed to capture 99 per cent of fly ash emissions.
 


TRENTON GENERATING STATION
Generating Capacity307 MW
LocationTrenton, Nova Scotia
  • Trenton Unit 5 was commissioned in 1969 and underwent a multi-million dollar complete refurbishment in 2009, leading to improved efficiency of the unit. 

  • he refurbishment at Unit 5 included a new generator and a ‘baghouse,’ a technology that acts as a large filter for the plant’s emissions. It significantly reduces fly ash emissions and allows the plant to have greater fuel flexibility. 

  • Trenton Unit 6 was commissioned in 1991 and was modified with a ‘Low-NOx’ combustion firing system in 2008 to prevent the creation of nitrogen oxides. 

  • Both Trenton units have electrostatic precipitators designed to capture 99 per cent of fly ash emissions from coal burning. 
 

Natural Gas

Natural gas is considered cleaner than other fossil fuels like coal and oil because it produces fewer air emissions. The Tufts Cove Generating Station in Dartmouth can burn oil or natural gas to generate electricity, but economical prices in recent years have led to it being run primarily with gas.

Because we’re producing so much electricity using natural gas at Tufts Cove, we’re making less power using coal at our plants, resulting in lower emissions and electricity costs.

The Tufts Cove Waste Heat Recovery project added a sixth generator to the plant in 2011 that produces up to 50 MW of electricity, enough to power up to 35,000 homes.

The new equipment captures waste heat from the exhaust streams of the two natural gas combustion turbines and uses it to power a new steam turbine and generator set, generating 25 MW of electricity without any additional fuel or emissions. A second 25 MW is generated by burning gas added directly into the waste heat stream from the turbines to increase energy output even further.

The Tufts Cove Waste Heat Recovery equipment captures waste heat from the exhaust streams of the two combustion turbines to power a new stream turbine and generator set.


 

TUFTS COVE GENERATING STATION
Generating Capacity 500 MW
Location Dartmouth, Nova Scotia
  • The Tufts Cove Generating Station consists of three oil-fired units commissioned in the 1960s and 1970s as well as two natural gas fired combustion turbines commissioned in 2003 and 2004.

  • The three Tufts Cove oil-fired units were converted to also burn natural gas in 1999-2000. In recent years the plant has run largely on natural gas.

  • Electrostatic precipitators installed in the stacks at Tufts Cove remove particulate matter and prevent it from rising through the stacks into the air.

  • The Tufts Cove Waste Heat Recovery system captures waste heat from the exhaust streams to produce up to an additional 50 megawatts of electricity, enough to power up to 35,000 homes.
 

Hydro & Tidal

Nova Scotia has a 100-year history of using small hydro developments on our rivers to generate power. The first hydro plant was installed in 1903 by mining interests on the Liscomb River in Guysborough County.

We own and operate 33 hydroelectric plants on 17 hydro river systems across Nova Scotia, totaling 400 MW of generation capacity. Learn more about hydro & tidal power here.

Wind

Nova Scotia’s growth in renewable electricity has been largely through the development of wind power.

There are now more than 300 commercial wind turbines generating electricity in Nova Scotia, making our province a national leader in wind energy as a percentage of total generation capacity. Learn more about wind power here.

Biomass

Biomass is a renewable energy source used around the world. We operate a 60 megawatt biomass power plant in Port Hawkesbury, which supplies as much as 3% of the province’s electricity. It’s a facility that is helping us reach renewable energy requirements and provides a source of firm renewable energy that can back up intermittent wind generation. Plus, it’s a locally sourced fuel that helps displace imported coal.

Fuel Oil

Until the 1970s, most of Nova Scotia’s electricity was generated by burning oil. In the wake of the OPEC oil crisis, the government decided to switch from imported oil to Cape Breton coal as Nova Scotia’s primary source of electricity.

Today, oil supplies only a small amount of Nova Scotia’s electricity. The Tufts Cove Generating Station in Dartmouth is designed to burn either oil or natural gas, but due to price considerations in recent years has run primarily on gas.

We also operate three oil-fired combustion turbine units, located in Victoria Junction (66 MW), Tusket (24 MW) and Burnside, Dartmouth (132 MW). Because they burn expensive light fuel oil and tend to be less efficient than other thermal generating units, the turbines typically serve as a secondary source of generation and are not commonly used.


COMBUSTION TURBINES
Location and 
Generating Capacity
Burnside Combustion Turbine
Generating capacity: 132 MW
Location: Dartmouth, Nova Scotia
 
Victoria Junction Combustion Turbine
Generating capacity: 66 MW
Location: Victoria Junction, Cape Breton Island
 
Tusket Combustion Turbine
Generating capacity: 24 MW
Location: Tusket, Southwestern Nova Scotia
  • Because they burn more expensive light fuel oil and tend to be less efficient than other thermal generating units, Nova Scotia Power’s combustion turbines typically serve as a secondary source of generation. 

  • An exception is the two natural gas-fired combustion turbines at Tufts Cove Generating Station which operate highly efficiently and which create lower levels of air emissions than other thermal facilities. This is because the units are newer and use cleaner burning natural gas.