5.6 Energy Sources: Hydro

Author: Sabrina Thomason

Sir Adam Beck Generating Station – Niagara Falls, Ontario. Source:


Hydroelectricity is produced when water falls from a higher point to a lower point creating speed and kinetic energy. The moving water is channeled through an intake canal and used to spin a turbine. The rotation winds a generator that transforms this movement into electricity that is sent out into the grid to power everything we do.

Hydroelectricity accounts for nearly one-third of Ontario’s electricity production (26%) and over half of Canada’s electricity (60%) thanks to the abundance of lakes and river systems nationwide.

Source: Ontario Electricity Generation by Fuel Type (2018)

Ontario’s hydroelectric fleet has 66 power stations, 241 dams, and 29 small hydroelectric plants on 24 river systems throughout the province. In 2019 this fleet produced over 32.5 terawatt hours of electricity. For context this is equivalent to powering 81.25 billion desktop computers for 1 hour each.

The first hydroelectric water turbine was invented in 1849 by engineer James Francis and remains the most widely used water turbine in the world today. Since this initial invention other turbine types have also been developed and include The Pelton Wheel, an impulse water turbine, in 1870 by Lester Allen Pelton and The Kaplan Turbine, a propeller type turbine with adjustable blades, in 1913 by Viktor Kaplan.

The Ontario hydroelectric system we know and depend on today is thanks to then MP, Adam Beck who at the start of the 20th century pushed forward the plans to build hydro dams in and around the Niagara Falls river systems. This collection of dams is now known as the Sir Adam Beck Generating Station and consists of two of Ontario’s largest dams and a power station. At the time very little of Ontario was fueled by electricity but rather natural gas. So, with this new source of energy Hydroelectric Power Commission of Ontario – HEPCO and Hydro Ontario was commissioned, and thus the province had to work to build infrastructure that would transport this new energy resource into cities and make it usable. The development of electric street cars in cities like Toronto is a biproduct of this transition toward electricity and away from gas.

However, there are some environmental drawbacks. Hydro compared to other power production sources in Ontario, across Canada and even globally, is relatively emissions free; yet most dams are made of concrete which is a very carbon heavy building method. Also, the areas surrounding hydro dams can be prone to flooding in the spring when there is an increased amount of moving water in the system. This flooding can cause huge amounts of methane to be released causing plant life in these areas to die and decompose while underwater.

Hydro dams can also have significant negative impact on river and lake ecosystems for aquatic life, such as fish populations like freshwater salmon and trout, which are dependent on seasonal cycles of fast and slow moving water and balanced PH. Dams can change and even regulate this water flow and disorient fish from knowing when spawning season is or when they need to move up or down steam. This directly affects fish populations and therefore indirectly affects other animal and plant populations that exist in this same ecological food chain. There are some efforts being done to help mitigate this damage to fish populations including salmon cannons. These tubes are set up in ways that help redirect schools of fish traveling up or down streams back towards less affected areas, so they can return to the correct path of travel and spawn at corresponding times of the year.

There are several pros and cons of hydroelectric power. Yet overall, for now hydroelectric dams are a simple yet effective source of renewable energy.


Energy B.C. “Run of River” February 2017. Retrieved from http://energybc.ca/runofriver.html

Government of Canada, Canada Energy Regulator. “Canada Energy Regulator / Régie De L’énergie Du Canada.” CER, Canada Energy Regulator / Régie De L’énergie Du Canada, 29 Jan. 2021, www.cer-rec.gc.ca/en/data-analysis/energy-markets/index.html.

Government of Canada, Environment Canada. “Environmental Impacts of Hydro Power.” Environment Canada – Air, 30 Mar. 2010, http://www.energybc.ca/cache/runofriver/www.ec.gc.ca/energie-energy/defaultc410.html

International Hydropower Association. “A brief history of hydropower.” https://www.hydropower.org/iha/discover-history-of-hydropower

Ontario Power Generation. “Hydroelectric Power.” OPG, 11 Nov. 2020,  www.opg.com/powering-ontario/our-generation/hydro/.


Sabrina Thomason is a mature student studying Interior Design in her 3rd year at Ryerson University.

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