What is coal and how is it extracted from the ground?
Coal is a hardened sedimentary rock made of ancient plant material. Coal deposits formed a long time ago, when the world’s continents looked very different and there were vast ancient seas. Organic materials, such as the remains of plants and animals, would sink to the bottom of the sea and become covered by sediment (i.e., rocks and sand) and compacted. Over the course of millions of years, the organic matter was transformed under high pressure and very hot temperatures, resulting in what we refer to today as fossil fuels—crude oil, natural gas, and coal. As a fossil fuel, coal is burned to produce heat and converted to electricity. It is one of the largest sources of electricity on Earth, but also produces some of the highest greenhouse gas emissions. Coal fuelled the start of the Industrial Revolution and remains the cheap energy source of choice for emerging economies.
In its natural state, coal exists in seams underground, and must be mined. To get at coal deep underground, coal mines plunge more than a kilometre into the Earth while shallow coal seams are strip-mined. Mining underground seams can be done in several ways, depending on the landscape and the characteristics of the coal seam, including depth, length, continuity and structure. Strip mines can be located right on the surface or on top of mountains, in which case, layers of soil and vegetation are stripped away to get at more shallow coal seams.
There are two types of coal: thermal coal is burned for electricity generation or heat, while metallurgical coal is used in steel production. About half the coal produced in Canada is thermal coal, while the rest is metallurgical.
How is electricity produced from coal?
Once out of the ground, coal is taken to a power plant where it is burned to heat water to make steam. The pressure created by that steam spins a turbine (this is mechanical energy), which in turn spins magnets inside a generator to produce electricity.
How is coal transported?
Coal sent for export is mainly transported by rail or by ship. Coal can also be mixed with water and sent via pipeline in a slurry. This is more efficient than train or truck, but uses a lot of water and is not common in Canada for long-distance transport.
How does the electricity produced from coal travel to where it needs to go?
There are three stages in the electricity system—generation, transmission, and distribution. Generation is about producing electricity, transmission is about moving it, and distribution is about delivering it to individual customers.
Transmission lines carry electricity from generating stations to end users or consumers. When electricity is running through these lines, some electricity is lost due to resistance and dissipates as heat. To reduce the amount of electricity lost in transit, these transmission lines carry high voltage electricity.
Power generators produce low voltage electricity and in order for this electricity to be transported to where it needs to go, the voltage has to be increased. A “step up” transformer is used to convert it to a higher voltage that the transmission lines can carry. Once the electricity reaches its destination, a substation “step down” transformer converts it back to a lower voltage so that it can be used by consumers.
The last part of the electricity grid is the distribution network, which is essentially the network of wires that takes the electricity from the transformers and carries it to the end-users. Electric utilities are private companies or government organizations that handle the production, transmission and distribution of electricity. Managing the electricity grid is a complicated process and an important responsibility.
Canada is connected to the United States through an international network called the North American Power Grid. Along the U.S. border there are more than 35 transmission connections, which allow for a flexible and mutually beneficial trade in electricity between Canada and its neighbour.
What is the electricity produced from coal used for?
Electricity is used in our homes and businesses for things like lighting, heating and cooling, and powering appliances and electronic devices. We live in a world dependent on electricity. From the refrigerator in your kitchen and to the computer that you’re using to access this website, electricity is the thing that makes possible most of our modern-day conveniences.
How does coal use impact the environment?
Of all the fossil fuels, coal produces the most greenhouse gas emissions, contributing to climate change and pollution. It also has an impact on the land because large areas of land are stripped of vegetation and mining disturbs the earth, leaving the landscape barren for many years. Power plants burn thermal coal to generate electricity, but the use of coal for electricity in Canada is gradually being phased out in an effort to step down the carbon ladder.
Coal emits about twice the CO2 of natural gas per unit of energy produced. It also produces acid rain-causing nitrogen oxides and sulfur oxides, mercury and other toxins, as well as the sooty particulates responsible for 18th-century London’s ubiquitous grime.
A number of Canadian communities, like Sydney, N.S., were built around coal mining, and collapsed when the mines closed; serious environmental problems left behind by the coal industry have only recently been addressed. The Sydney Tar Ponds, for example, were created by decades of runoff from a nearby coal-fired steel mill. Decades of work and hundreds of millions were spent to clean up the site.
Where do we find coal mines and coal-fired power plants in Canada?
- The largest producer of coal in Canada is British Columbia. Up to 90 per cent of the coal mined in British Columbia is metallurgical coal, with the rest being thermal coal. There are seven mines in British Columbia that produce thermal coal. However, British Columbia doesn’t get any of its electricity or heating from coal and exports most of it to international markets. Westshore Terminals close to Vancouver is the largest coal terminal on North America’s west coast, which mainly sends coal overseas by ship to Asia.
- The second-largest producer of coal is Alberta. Coal is burned to generate nearly half of the province’s electricity. This accounts for about two-thirds of Canada’s total electricity generation.
- The third-largest coal producer in Canada is Saskatchewan, which is also the second-largest producer of electricity generated from coal.
- Nova Scotia represents the third-largest producer of coal-fired electricity generation in Canada. About two-thirds of Nova Scotia’s electricity is generated from burning coal.
Did you know?
In 2018, the government of Canada announced regulations to phase out coal-fired electricity generation by 2030.