Ontario Electricity Rates Explained: TOU, Tiered, and UltraLow Overnight

Three price plans, one meter

Short answer: Most Ontario households served under the Ontario Energy Board's Regulated Price Plan (RPP) can choose how their electricity energy is priced: Time-of-Use (TOU), Tiered, or Ultra-Low Overnight (ULO). The designs differ in what they reward. TOU rewards avoiding weekday peaks, Tiered rewards simply using less, and ULO rewards running big loads overnight.

This guide explains the structures, not a price snapshot: the OEB resets RPP prices on a regular cycle, so read the current numbers on the OEB site (cited below) and use your own meter data to choose. It deepens our general utility rate plans guide for Ontario households.

What sits underneath all three designs

Your Ontario bill has more than energy on it. Delivery charges (your local distributor's wires, partly fixed and partly per-kWh), regulatory charges, and taxes are billed alongside the energy portion. Switching between TOU, Tiered, and ULO reprices the energy portion only. That is why a plan change moves the bill by less than the headline rate difference suggests, and why our electric bill breakdown is worth reading before optimizing anything.

Design 1: Time-of-Use

TOU divides the day into off-peak, mid-peak, and on-peak periods, with the map changing between summer and winter schedules. Weekends and holidays are off-peak all day. TOU suits households whose daytime weekday use is naturally low (everyone out at work and school, no home business) or who can move laundry, dishwashing, and EV charging into evenings and weekends without heroics.

The failure mode is structural, not moral: a home occupied all day with electric heating or cooling in the peak window will pay the on-peak price for its largest loads. Interval data settles it; our time-of-use strategy guide shows how to model a plan from a year of meter data before switching.

Design 2: Tiered

Tiered pricing charges one price up to a monthly kilowatt-hour threshold and a higher price above it, with the threshold differing between summer and winter. When you use the energy does not matter; how much does. Tiered suits small, steady households (many apartments and condos) that stay under the threshold, and anyone whose schedule cannot move: shift workers, home businesses, medical equipment.

The check is simple: look at your last twelve bills. If your usage lives under the threshold most months, Tiered quietly wins. If winter heating pushes you deep into the second tier, compare carefully.

Design 3: Ultra-Low Overnight

ULO is the newest design: a very low overnight price window every night, paired with higher on-peak prices on weekday late afternoons and evenings, with mid-peak and weekend shoulder periods between. It was designed for households that can put serious load into the night: EV charging is the headline case, along with water heating, laundry, and battery charging.

ULO is a bet you must win on schedule. The overnight discount is deep, but the on-peak penalty applies to cooking, cooling, and everything else a household does at 5 PM in January. Model it with real intervals before switching; EV owners should start with our EV charging cost guide.

How to choose: your data, three sums

1. Download your hourly or interval usage from your distributor's portal (most offer it; Green Button data is the standard format).
2. Price the same twelve months three ways using the OEB's current published prices for each design. The OEB also provides a bill comparison calculator for exactly this.
3. Stress the answer: does the winning design still win in your worst month, and does it depend on behavior you will realistically keep in February?

You can switch designs through your distributor; plan changes are not permanent commitments, but give each design a full season before judging it.

Who should not overthink this

If your monthly bill is small and mostly delivery charges, the design choice moves little money; pick Tiered simplicity or default TOU and spend your attention elsewhere. The design decision pays in proportion to shiftable load: EVs, electric water heating, electric space heating, and batteries are where the three sums earn their time.

Reading your Ontario bill against the three designs

Whatever design you are on, pull one winter and one summer bill and find three things: total kilowatt-hours, how they split across the periods or tiers your design uses, and how much of the bill is delivery and fixed charges that no design change can move. That last number disciplines expectations: plan savings apply only to the energy slice. If delivery dominates your bill (common for low-usage and rural accounts), the design decision is worth correspondingly less time. If the energy slice is large and your split shows heavy on-peak or deep second-tier use, the three-sum exercise from your distributor's data portal can pay for an afternoon many times over. Ask your distributor for the interval data if the portal hides it; Ontario distributors provide it, and Green Button format makes it portable.

Electric heating and heat pumps: the Ontario special case

Electric space heating concentrates consumption exactly where the designs disagree most. On TOU, a cold January weekday prices your largest load at on-peak for part of the day. On Tiered, the same month blows through the threshold early and prices most heating at the second tier. On ULO, overnight pre-heating and smart thermostat scheduling can move a real share into the discount window, at the cost of on-peak exposure for evening life. There is no universal winner; there is only your interval data. Households adding a heat pump should rerun the three sums with the heat pump's expected load before choosing, and cold-climate heat pump owners should pay special attention to auxiliary heat hours, which land wherever the weather puts them.

Switching without regret

Treat the first switch as an experiment with a review date. Note the date you change, keep the bills, and compare after a full season against your model. If the design underperforms the model, the usual causes are behavioral (the dishwasher did not actually move) or seasonal (your sample months were kind). Both are fixable, and you can switch again under the distributor's process. What you should not do is switch on a neighbor's result: two houses on the same street routinely produce opposite winners, because the designs price habits, and habits are not shared.

North of the border context: how Ontario's design compares

Ontario's choice among three regulated designs is unusual in North America. Alberta makes you shop a market (Alberta guide), BC hands you a two-step conservation price (BC guide), Texas runs a competitive retail market (Texas guide), and California imposes one engineered time-of-use design (California guide). Ontario's version of flexibility is a menu, not a market: the regulator designs the options, and you pick the one your meter data prefers. That makes the skill to learn here selection rather than shopping. Households that move between provinces routinely misapply the old province's instincts; if you have just arrived in Ontario, run the three sums before assuming your TOU habits from elsewhere still point the right way.

A note on how Ontario prices get set

RPP prices are set by the Ontario Energy Board on a regular cycle (historically each May and November) to forecast the cost of supplying regulated customers, including the Global Adjustment that recovers contracted and regulated generation costs. That is why your design choice matters but the levels move for everyone at once, and why a plan that won last winter should be re-run each spring with fresh prices and a fresh year of your own data. Distributors occasionally adjust delivery rates on their own cycles as well, which is another reason to model on your own meter history rather than on a neighbour's bill or a year-old explainer's example. The structures above endure; every specific number deserves a fresh look at the OEB page.

Frequently Asked Questions

Can I switch between TOU, Tiered, and ULO freely?

Ontario RPP customers can generally choose and change their price plan through their local distributor, subject to the distributor's process and timing. Confirm the mechanics and any notice period with your distributor, and check the current OEB rules, since the program terms are set provincially.

Does ULO make sense without an EV?

Only if you have other serious overnight load or a genuinely nocturnal household. Without a big shiftable load, the higher on-peak prices tend to eat the overnight discount. Model it rather than guessing.

Do these plans apply to businesses too?

The RPP designs discussed here are primarily residential and small-business regulated pricing, with eligibility rules. Larger or demand-billed accounts live under different structures; your distributor's rate pages are the reference.

Where do retailer contracts fit?

Ontario households may alternatively sign with an energy retailer at a contracted price. That is a separate product from the RPP designs, with its own contract risks and exit terms. Read any retailer contract fully and compare against the OEB's published information before signing.

Do I need a smart meter for these plans?

Time-based designs require interval metering, which Ontario deployed broadly. If your meter or distributor cannot support a design, they will tell you during the switch request.

The bottom line

Choose the design that prices your actual life cheapest: TOU for empty-at-peak houses, Tiered for small steady users, ULO for disciplined overnight load. Your intervals, three sums, one season of patience.

About the Editorial Team EnergyBS reviews public program rules, product specifications, utility rates, and reader-facing cost assumptions. Treat savings figures as estimates until you verify local prices, permits, rebates, and contractor quotes.