Quick answer
It's an optional price plan with electricity at 3.9¢ per kWh from 11 p.m. to 7 a.m. every day, but 39.1¢ on weekdays from 4 to 9 p.m. It pays off if you can move big loads like EV charging overnight and keep weekday evening use low.1
The prices and hours
| Period | Hours | Price |
|---|---|---|
| Ultra-low overnight | Every day, 11 p.m.–7 a.m. | 3.9¢/kWh |
| Weekend off-peak | Weekends and holidays, 7 a.m.–11 p.m. | 9.8¢/kWh |
| Mid-peak | Weekdays 7 a.m.–4 p.m. and 9–11 p.m. | 15.7¢/kWh |
| On-peak | Weekdays 4–9 p.m. | 39.1¢/kWh |
As listed by the Ontario Energy Board for rates effective November 1, 2025.1
A simple example
Charging an electric vehicle with 10 kWh costs about 39¢ at the overnight price, but about $3.91 if the same charge happens during weekday on-peak hours. That's the same energy at ten times the price, before delivery charges and rebates.
Who should be careful
- Homes that heat or cook with electricity in the early evening, when on-peak is 39.1¢.
- Anyone at home during weekday afternoons and evenings who can't shift use.
What makes it work better
- An EV charger set to start after 11 p.m.
- A home battery that charges overnight and powers the house from 4 to 9 p.m.
- A smart thermostat that pre-heats or pre-cools before the on-peak window.
Common follow-up questions
Is Ultra-Low Overnight available everywhere in Ontario?
It is one of the three regulated price plans the Ontario Energy Board lists for residential and small business customers. Ask your local utility how to switch.
What if my usage doesn't fit?
You can switch plans again. Compare a few months of your own hourly usage before and after to see which plan costs less.
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Answers are general information as reported by the sources listed on the date shown, not personal financial or technical advice. Programs, prices and rules change. Canadian Energy Standard is an independent company, not affiliated with any government, utility or program named here.