The idea
Ontario’s electricity comes from a mix of sources, and each one trades off differently between cost, emissions, land, and reliability.
| Source | Emissions while running | Reliable output? | Main drawback |
|---|---|---|---|
| Nuclear | Very low | Yes, constant | Long-lived waste; huge build cost |
| Hydroelectric | Very low | Mostly | Floods land; disrupts rivers and fish |
| Wind | None | No — varies with weather | Needs backup or storage |
| Solar | None | No — daily and seasonal | Same, plus winter in Canada |
| Natural gas | Substantial | Yes, and fast to start | Emits and methane leaks |
pie title Ontario's generation mix "Nuclear" : 55 "Hydro" : 24 "Wind" : 9 "Natural gas" : 8 "Solar and other" : 4
Check the numbers before you quote them
The mix shifts year to year with demand, water levels, and which reactors are being refurbished. Treat the chart above as a rough illustration, then find current figures from the system operator — that is exactly the scientific literacy skill described in the scientific literacy expectation.
The question worth arguing about
There is no source without a cost. The real question is which costs we are willing to carry, and who ends up carrying them — which is what Energy Source Debate is for.
Curriculum connection
D1.1
assess social, environmental, and economic benefits and challenges resulting from the production of electrical energy from various sources
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D1.2
evaluate how electrical energy production and consumption impact various communities locally or globally, and describe ways to achieve sustainable practices
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D1.4
analyse social, environmental, and economic impacts of emerging technologies related to electrical energy production, consumption, storage, and conservation
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