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.
Electricity is produced through mechanical energy, which is harnessed by rotating turbines. Individual generators produce electricity using different kinds of resources. This may include facilities such as coal-burning plants, natural gas fired plants, hydroelectric dams, wind farms, solar panel installations, as well as many others. The resources used in energy production vary significantly and interact differently with the electricity grid.
Some generators, such as nuclear power plants, have limited “ramp rate” flexibility, which is the ability of a power generator to increase or decrease energy output. To meet demand for energy at peak times, more flexible power generators are used, such as natural gas fired plants. Other technologies, such as solar and wind are used whenever they are available. The integration of all these different energy sources requires careful oversight and management.
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. Consumers are beginning to play a more active role in the electricity system. For example, initiatives like net-metering and feed-in-tariffs allow for consumers to pursue renewable energy production to offset their electricity bills.
The North American power grid
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.
In August 2003, through a combination of natural factors and human error, the largest blackout in human history left about fifty million people without power. The blackout originated in Ohio, but grew to envelop most of northeastern North America, reaching as far as Toronto and Ottawa in Canada. A hot summer day caused a peak in demand for power, straining generators and overloading transmission lines. A coal-fired generator near Cleveland broke down. Then, a major transmission line sagged and burnt out when it came in contact with tree branches, knocking out power for the area. The power surge overloaded more transmission lines and those in turn tripped off circuit breakers, causing a cascade of failures across state lines and national borders.
Although the blackout only lasted for about a day, it had significant economic impact. Businesses were either asked, or forced, to cut back power for at least a week while repairs went on. Loss in power caused many nuclear plants to be shut down for safety reasons because they had nowhere to send their power, a process which was both costly and time-consuming. This blackout underscored the importance of responsible management and the United States adopted more stringent reliability standards, reflecting the existing standards in Canada.
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. Canada provides enough electricity to power about 7 million American homes.
What is the future of the electricity grid?
Technology is advancing and changing rapidly, meaning that the electricity grid cans be improved and modernized. Newer technologies for storing energy are being used to better integrate renewable energies such as solar and wind, or to better deal with electricity peaks. By storing energy during times of low demand, that energy can then be used during periods of high demand.
When discussing modernization of the electricity grid, the idea of the smart grid is at the forefront. “Smart” stands for Self-Monitoring Analysis and Reporting Technology, which means that there would be two-way communication between devices and data collection systems. The idea is to have more control over the energy use of products to conserve energy.
Smart meters track electricity consumption and report it to the utility so that homeowners and businesses can make more informed decisions about their energy use. The use of smart devices and appliances in homes and businesses is also on the rise. For example, with an HVAC systems it is possible to manage the air conditioning and heating in a home, reducing energy use when no one is home.
All these elements contribute to the network that makes up a smart grid. The advantages of a smart grid are manifold. It would help with the detection of outages, allow power to be distributed and managed more efficiently between utilities and customers, better integrate renewable energy sources, and possibly allow for the integration of electric vehicles into the grid. Although there are security and privacy concerns about having the electricity grid connected to a system that collects data, smart technology will play a big part in the future of electricity use in Canada.
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