Your Ontario Electricity Rate — Decoded.
Most homeowners don't know which rate plan they're on — or how much it's costing them. ShiftAI models Time-of-Use and Ultra-Low Overnight pricing hour by hour, so your solar savings estimate actually reflects your bill.
Ontario electricity pricing is time-dependent. Your solar estimate should be too.
Ontario runs one of the most time-variable electricity pricing systems in Canada. Under the Regulated Price Plan (RPP), set by the Ontario Energy Board, residential customers pay different rates depending on when— not just how much — they use power.
There are three plans to choose from: Time-of-Use (TOU), Ultra-Low Overnight (ULO), and Tiered. Most homeowners are on TOU by default.
Why does this matter for solar? Because a solar panel produces power during the day — and whether that energy is worth 15.7¢/kWh (TOU mid-peak) or 39.1¢/kWh (ULO on-peak) changes your 25-year savings estimate by tens of thousands of dollars.
ShiftAI models both plans correctly.
“Most solar tools use a flat rate. Ontario doesn't have one.”
— ShiftAI Methodology v1.0
Time-of-Use (TOU) Pricing
Most Ontario households pay TOU rates. Electricity costs more during morning and early evening weekday hours — and less overnight and on weekends.
| Period | Hours | Rate |
|---|---|---|
| Off-Peak | 12 AM – 7 AM | 9.8¢/kWh |
| On-Peak | 7 AM – 11 AM | 20.3¢/kWh |
| Mid-Peak | 11 AM – 5 PM | 15.7¢/kWh |
| On-Peak | 5 PM – 7 PM | 20.3¢/kWh |
| Off-Peak | 7 PM – 12 AM | 9.8¢/kWh |
Effective: November 1, 2025 – April 30, 2026 · Source: Ontario Energy Board (OEB)
11 AM–5 PM — Solar production peaks during mid-peak hours, directly offsetting your most expensive daytime electricity.
5–7 PM weekdays — On-Peak hours. ShiftAI knows exactly what your solar panels are doing at this moment.
Your solar panels produce the most power between 9 AM–3 PM — which overlaps with mid-peak (winter) or on-peak (summer) TOU hours. ShiftAI calculates exactly how many kWh are generated in each period, and prices them correctly.
A flat-rate calculator misses this entirely.
Ultra-Low Overnight (ULO) Pricing
ULO was designed for EV owners and smart-home users. For solar homeowners with battery storage, it's the most powerful rate arbitrage available in Ontario.
| Period | Hours | Rate |
|---|---|---|
| Ultra-Low Overnight | 12 AM – 7 AM | 3.9¢/kWh |
| Mid-Peak | 7 AM – 4 PM | 17¢/kWh |
| On-Peak | 4 PM – 9 PM | 39.1¢/kWh |
| Mid-Peak | 9 PM – 11 PM | 17¢/kWh |
| Ultra-Low Overnight | 11 PM – 12 AM | 3.9¢/kWh |
| Period | Hours | Rate |
|---|---|---|
| Ultra-Low Overnight | 12 AM – 7 AM | 3.9¢/kWh |
| Weekend Off-Peak | 7 AM – 11 PM | 7.6¢/kWh |
| Ultra-Low Overnight | 11 PM – 12 AM | 3.9¢/kWh |
Effective: November 1, 2025 – October 31, 2026 · Source: Ontario Energy Board (OEB)
A battery charged overnight at ULO rates and discharged during the 4–9 PM on-peak window can save Ontario homeowners an additional $1,000–$1,500/year— on top of standard solar savings.
ShiftAI models this arbitrage in every estimate where ULO is applicable.
Rates set by the Ontario Energy Board. Effective Nov 1, 2025. Arbitrage savings estimate based on 700 kWh/month household. Source: OEB.
Battery storage + ULO = the highest-yield residential arbitrage strategy in Ontario.
Charge your EV at 3.9¢/kWh overnight. Deploy that stored energy — or your solar — during the 39.1¢ peak window.
ULO vs. TOU at a Glance
| TOU | ULO | |
|---|---|---|
| Cheapest rate | 9.8¢ | 3.9¢ |
| Most expensive | 20.3¢ | 39.1¢ |
| Rate spread | 10.5¢ | 35.2¢ |
| Peak hours | 7–11 AM, 5–7 PM | 4–9 PM (weekdays) |
| Best for | Most homes | Solar + Battery owners |
Which Rate Plan Is Right for You?
| Tiered | TOU | ULO | |
|---|---|---|---|
| How it works | Pay by volume | Pay by time of day | Pay by time of day (4 periods) |
| Cheapest rate | 10.3¢/kWh | 9.8¢/kWh | 3.9¢/kWh |
| Most expensive | 12.5¢/kWh | 20.3¢/kWh | 39.1¢/kWh |
| Seasonal changes | Threshold changes | On/Mid-Peak hours swap | No — same year-round |
| Weekend pricing | Same as weekday | Off-Peak all day | Weekend Off-Peak all day |
| Best without solar | ✓ Predictable | ✓ If you shift usage | ✗ Risky |
| Best with solar | Moderate | ✓ Good | ✓✓ Best with battery |
| ShiftAI models it | ✓ | ✓ | ✓ |
Rates set by the Ontario Energy Board. Effective November 1, 2025. Subject to annual review each November 1. Source: OEB Regulated Price Plan.
Solar + Battery on ULO: The highest-ROI combination available to Ontario homeowners.
Solar + Battery on ULO: How the Math Works
Conservative estimate: $1,000–$1,500/year in additional annual savings compared to the same system on TOU pricing.
This is the ULO arbitrage that ShiftAI includes in every residential estimate where battery storage is present.
ShiftAI models Ontario rates correctly. Here's how.
See exactly how TOU and ULO affect your solar savings.
ShiftAI runs a free, grid-aware estimate for your Ontario home — modelling the rate plan you're actually on.