Electricity

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.

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.

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.

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.