2.2 RENEWABLE GENERATION More than half of Canada’s electricity is generated through renewable sources. Introduction As we have learned, renewable electricity is generated by sources that can be used continuously without being depleted and are generally free of greenhouse gas emissions. Let’s learn more about the different sources of renewable electricity, and how they generate that electricity.
Hydroelectricity Hydroelectricity involves harnessing the energy in flowing or falling water. Since various regions of Canada have abundant water—and geographic features that lend themselves well to highly efficient hydroelectric projects—this form of generation accounts for 60% of Canada’s electricity. In some parts of the country “hydro” is commonly used in a generic sense to refer to electricity. This reflects the prevalence of hydroelectricity in the supply mix in those regions. Properly speaking, however, it refers only to electricity generated at a hydroelectric facility.
Hydro Generation and Storage Hydroelectricity is the only renewable source of electricity that is well suited to generate baseload supply, meaning the minimum amount of electricity that we need to have consistently available. It is also dispatchable, meaning grid managers can decide when to use hydroelectricity and when to store potential generation for later use. There are two major kinds of hydroelectricity generation projects including dams and reservoirs and run-of-river projects. Dams and Reservoirs Most hydroelectricity is generated from projects that use a dam to create a reservoir. Water can be stored in the reservoir, allowing for ongoing generation even in drier seasons, and for generation to be scheduled for periods when other sources of electricity are less available. Pumped storage projects are becoming more common and operate essentially the same as reservoir-based projects. The difference being that water is pumped to an elevated reservoir, at a time when surplus or lowcost electricity is available for later use. Given the storage capacity of these two types of projects, hydroelectricity plays a very important role in balancing demand and supply on the electricity grid, and in ensuring that more generation from other renewable sources, like wind and solar, can be integrated into the grid while maintaining reliability. Run-of-River Another common form of hydroelectric projects is run-of-river, in which the energy in a river or stream is directly harnessed without use of a reservoir. While these projects lack storage capacity, they are lowimpact and add to the diversity of generation supply. They are also well suited to meeting generation needs in remote and off-grid areas.
Electricity Canada | Electricity Fundamental in Canada: Student Handbook
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