Time-of-Use Hydro Rates in Ontario 2026: TOU, ULO and Tiered

Source: Ontario Energy Board (OEB) Regulated Price Plan, prices set November 1, 2025, in effect through October 31, 2026. Supply prices only.

Quick answer

1. What are the current Ontario time-of-use rates?

Ontario sets one set of Regulated Price Plan (RPP) prices each year on November 1. The prices below took effect on November 1, 2025 and stay in place until October 31, 2026. They cover the Electricity line on your bill, which is the cost of the power itself. This is the table that answers the head question, so it sits right at the top.

On-peak power costs roughly twice as much as off-peak (20.3 vs 9.8 cents). That gap is the whole point of time-of-use: the system charges more when the grid is busiest so households have a reason to shift heavy loads, like laundry, dishwashers and EV charging, to cheaper hours. Since nearly two thirds of home usage already lands in off-peak, most of your kWh are billed at the lowest price by default.

2. Ontario peak hours: summer vs winter

The prices stay the same all year, but the hours when on-peak and mid-peak apply flip between seasons. Summer runs May 1 to October 31, winter runs November 1 to April 30. Off-peak hours never change. On weekends and statutory holidays, off-peak applies all day in both seasons.

The logic follows demand. In summer, the grid peaks midday when air conditioners run hardest, so 11 a.m. to 5 p.m. is on-peak. In winter, demand spikes at the morning and evening edges of the day when people wake up and come home, so those windows become on-peak instead. As of June 2026, summer hours are in effect.

3. Ultra-Low Overnight (ULO) rates

ULO is the second time-based plan. It offers a very cheap overnight price in exchange for a steep weekday evening price. The ULO hours are the same all year. This plan rewards households that can move large loads to the middle of the night.

The overnight rate of 3.9 cents is the cheapest residential price in Ontario, about 60 percent below TOU off-peak. The catch is the 39.1 cent weekday on-peak, nearly double TOU's on-peak and almost ten times the ULO overnight rate. ULO pays off only if you genuinely keep usage out of the 4 to 9 p.m. window on weekdays and push it overnight. An EV that charges from 11 p.m. is the textbook case. For the charging math, our EV charging cost calculator lets you compare ULO overnight against TOU off-peak directly.

ULO break-even for an EV. Say you drive 1,500 km a month and your EV uses about 18 kWh per 100 km, so roughly 270 kWh a month for charging. Charging all of it overnight, the supply cost difference between ULO and TOU off-peak is what matters:

Charging the EV alone saves about $16 a month on ULO. That is real, but it only holds if the rest of your home usage does not drift into the 39.1 cent window. If your household burns 200 kWh a month between 4 and 9 p.m. on weekdays, that block alone costs $78.20 on ULO versus $40.60 on TOU on-peak, wiping out the EV savings several times over. ULO is a plan you commit to with the whole house, not just the car.

4. Tiered rates and thresholds

Tiered pricing ignores the clock. You pay one flat price at any hour until you cross a monthly usage threshold, then a slightly higher price for the rest of the month. The threshold changes by season because winter heating pushes usage up.

For small business and other non-residential customers the threshold is a flat 750 kWh per month all year. Tiered is the plan for people who cannot control when they use power: someone working from home all day, a household on a fixed schedule, or anyone who finds the on-peak window unavoidable. The Tier 1 price of 12.0 cents sits between TOU off-peak (9.8) and TOU on-peak (20.3), so Tiered protects you from the on-peak penalty but never gives you the deepest off-peak savings.

5. TOU vs ULO vs Tiered: which is cheapest?

There is no single winner. The right plan depends on when you use power, not how much. Here is the quick decision guide, then a worked comparison.

Worked comparison. Take a household using 750 kWh in a summer month, split as 60 percent off-peak, 20 percent mid-peak, 20 percent on-peak under TOU timing.

For this profile Tiered edges out TOU because the on-peak share is high and not shiftable. Flip the assumption so the household moves most usage to off-peak, and TOU drops below $80 while ULO with disciplined overnight charging beats both. The lesson: ULO is powerful but unforgiving, and Tiered is the safe default when your schedule is fixed. Run your own numbers with the electricity cost calculator.

6. How to switch your price plan

Switching is free and reversible. You submit an election form to your local utility (Hydro One, Toronto Hydro, Alectra, Hydro Ottawa, and so on), either online or on paper. The new plan normally starts on your next billing cycle. There is no OEB fee, and you can switch back if the plan does not work out, though utilities may limit how often you change within a short period.

Before switching, pull two or three months of your hourly usage data through the OEB's Green Button program or your utility portal. That tells you what share of your kWh actually falls in each window, which is the only honest way to compare plans. Guessing usually overstates how much you can shift.

7. The rest of your bill: delivery and the OER

The TOU, ULO or Tiered rate is only the supply line. A full Ontario hydro bill adds:

• Delivery: the cost to move power to your home, part fixed and part per kWh. This is often the second largest line.
• Regulatory charges: the cost of running the grid and wholesale market.
• HST: 13 percent on the subtotal.
• Ontario Electricity Rebate (OER): a pre-tax credit that, as of November 1, 2025, is 23.5 percent of most of the bill, up from 13.1 percent. It appears as a negative line near the bottom.

Because of these extra lines, supply is only about 40 to 55 percent of the total for a typical home. That is why your bill is higher than the rate times your kWh, and also why shifting usage moves your bill less than the raw rate gap suggests: you only save on the supply portion. For a full picture of average Ontario bills and how supply, delivery and the OER stack up, see our Ontario electricity cost guide.

The OER jump matters more than it looks. Moving the rebate from 13.1 to 23.5 percent on November 1, 2025 lowered the effective price of every kWh by about a tenth across the board, no matter which plan you are on. It does not change which plan is cheapest, since the rebate applies to all of them, but it does shrink the dollar gap between plans. A household weighing a switch should run the comparison on supply cost first, then remember the rebate scales both options down together.

8. Worked example: estimating a monthly bill

A home on TOU uses 900 kWh in a winter month, billed roughly 65 percent off-peak, 17 percent mid-peak, 18 percent on-peak.

1. Off-peak: 585 kWh × 9.8¢ = $57.33
2. Mid-peak: 153 kWh × 15.7¢ = $24.02
3. On-peak: 162 kWh × 20.3¢ = $32.89
4. Supply subtotal: $114.24
5. Add delivery + regulatory (say $75), subtotal $189.24
6. Apply OER 23.5%: credit of about $44.47, subtotal $144.77
7. Add HST 13%: about $18.82
8. Estimated total: about $164

Delivery rates vary by utility, so treat this as a ballpark. The point of the breakdown is to show where your money goes: of the $114 supply cost, off-peak power is the single largest chunk even though it is the cheapest rate, simply because most kWh land there.

9. Common mistakes

Four errors cost Ontario households the most money on these plans. First, assuming TOU off-peak and ULO overnight are the same, they are not: 9.8 vs 3.9 cents is a large gap, but ULO punishes the 4 to 9 p.m. window hard. Second, switching to ULO without an EV or another large shiftable load, which usually backfires. Third, ignoring weekends, where off-peak applies all day and is the best time for laundry and batch cooking. Fourth, comparing plans on the rate alone and forgetting that you only save on the supply portion of the bill, not delivery or regulatory charges.

One more: people forget statutory holidays count as off-peak all day. Ontario has nine to eleven observed holidays a year where every hour is billed at the cheapest rate, so plan heavy chores around them.

10. Free calculators

These tools turn the rates above into dollars for your own usage:

Related reading: Ontario electricity cost guide, electricity rates by province, and cost to charge a Tesla at home.

11. FAQ

Disclaimer: Electricity rates and bill components change and vary by utility. This guide covers regulated supply prices only; delivery and regulatory charges differ by local distributor. Verify current rates and your own plan details with your utility or the Ontario Energy Board before making financial decisions. This is general information, not financial advice.

Data sources: Ontario Energy Board (OEB) Regulated Price Plan, prices effective November 1, 2025 (oeb.ca electricity rates page); OEB RPP backgrounder October 17, 2025; Ontario Electricity Rebate adjustment to 23.5 percent effective November 1, 2025. Figures are supply prices in Canadian cents per kWh. Current as of June 2026.