What Are ULO Rates in Ontario?
Why Choose Home Battery Backup in Muskoka?
- Cost savings by utilizing ULO rates for charging.
- Reliable power supply during outages.
- Environmental benefits by reducing reliance on grid electricity.
- Potential eligibility for HRSP rebates.
The Ultra-Low Overnight (ULO) plan is one of three time-of-use (TOU) electricity pricing options available to Ontario residential customers. It was introduced by the Ontario Energy Board to encourage homeowners to shift electricity usage to overnight hours when demand on the grid is lowest.
Under the ULO plan, electricity prices vary dramatically depending on when you use power:
| Time Period | Hours | Rate per kWh |
|---|---|---|
| Ultra-Low Overnight | 11 PM – 7 AM | 3.9¢ |
| Weekend Off-Peak | Weekends & holidays, all day | 7.6¢ |
| Mid-Peak | 7 AM – 4 PM, 9 PM – 11 PM (weekdays) | 12.2¢ |
| On-Peak | 4 PM – 9 PM (weekdays) | 39.1¢ |
The key number: 3.9¢ vs. 39.1¢. That's a 10x difference between the cheapest and most expensive hours. This price gap is what makes battery storage so financially attractive in Ontario.
How Battery Storage Creates an Arbitrage Opportunity
Think of your home battery as a simple buy-low, sell-high machine for electricity:
- Charge overnight (11 PM – 7 AM) — Your battery fills up at the ultra-low rate of 3.9¢/kWh. A 13.5 kWh battery costs roughly $0.53 to fully charge.
- Power your home during peak (4 PM – 9 PM) — Instead of buying electricity at 39.1¢/kWh from the grid, your home draws from the battery. That same 13.5 kWh of stored power would have cost $5.28 from the grid at peak rates.
- Save the difference — Every day, you're effectively saving 35.2¢ on every kWh you shift from peak to overnight. For a 13.5 kWh battery, that's roughly $4.75 in savings per day.
Daily math: 13.5 kWh × (39.1¢ − 3.9¢) = 13.5 × 35.2¢ = $4.75/day savings. Over a year, that's approximately $1,734 — just from peak-hour arbitrage.
Realistic Annual Savings Estimates
Not every day is perfectly optimized. You won't always fully discharge the battery during peak hours, weekends have lower rates, and your usage patterns will vary seasonally. Here are conservative, real-world estimates:
| Battery Size | Daily Savings (avg.) | Annual Savings |
|---|---|---|
| 5 kWh (e.g., Enphase IQ 5P) | $1.50–$1.76 | $550–$640 |
| 10 kWh | $2.80–$3.52 | $1,000–$1,280 |
| 13.5 kWh (e.g., Tesla Powerwall 3) | $3.60–$4.75 | $1,300–$1,734 |
| 20 kWh (multi-battery) | $5.00–$7.00 | $1,800–$2,550 |
These figures account for weekends (when peak rates don't apply), seasonal variation, and the reality that most households don't fully cycle their battery every single day. If you also add solar panels, your savings increase further because the solar offsets daytime mid-peak usage and helps recharge the battery.
Who Qualifies for the ULO Rate Plan?
The ULO plan is available to all Ontario residential electricity customers served by a local distribution company (LDC). This includes homeowners and cottage owners in:
- Hydro One territory — covers most of Muskoka District, including Huntsville, Gravenhurst, Bracebridge, Dorset, Port Carling, and rural cottage areas
- Alectra Utilities — serves parts of Barrie and surrounding areas
- InnPower — serves Innisfil
- Collus PowerStream / EPCOR — serves Collingwood and area
To switch to ULO, you simply contact your local utility and request the rate change. There is no fee and no special equipment required — your existing smart meter already tracks time-of-use data. The switch typically takes effect within one billing cycle.
ULO + Battery: A Worked Example
Let's walk through a concrete scenario for a typical Muskoka or Simcoe County household:
| Item | Details |
|---|---|
| Battery | Tesla Powerwall 3 (13.5 kWh) |
| Installed cost | $18,000 |
| HRSP rebate | −$4,050 ($300 × 13.5 kWh) |
| Net cost | $13,950 |
| Annual ULO savings | ~$1,500 (conservative) |
| Payback period | ~9.3 years |
| Battery warranty | 10 years (typical) |
| Expected lifespan | 15–20 years |
| Savings over 20 years | $30,000+ (accounting for rate increases) |
With Ontario electricity rates rising an average of 3–5% annually, your savings accelerate each year. By year 10, you may be saving $2,000+ per year — and the battery still has 5–10 years of useful life remaining.
What About Mid-Peak Hours?
A battery doesn't just save you money during peak hours. By programming your battery to also cover mid-peak hours (12.2¢/kWh), you capture additional savings — especially if you have a larger battery that still has capacity after covering the peak window. The difference between mid-peak and overnight isn't as dramatic (8.3¢ vs. 35.2¢ for peak), but it adds up over a full year.
Smart battery systems like the Tesla Powerwall and Enphase IQ can be programmed to prioritize peak hours first, then extend into mid-peak as capacity allows. Your installer can configure this based on your household's specific usage pattern.
How to Get Started
Taking advantage of ULO + battery savings is a straightforward process:
- Switch to ULO — Contact your utility (Hydro One, Alectra, etc.) and request the Ultra-Low Overnight rate plan. It's free.
- Get a battery quote — Connect with a qualified installer through muskokaenergystorage.ca for a free, no-obligation assessment
- Claim your HRSP rebate — Your installer applies the rebate directly, reducing your upfront cost by up to $5,000 (or $10,000 with solar)
- Start saving — Your battery automatically charges overnight and discharges during peak hours, reducing your hydro bill from day one
Connect With a Local Installer
Ready to start saving on Ontario's ULO rate plan? We connect homeowners across Muskoka District and Simcoe County with qualified battery storage installers — free and no obligation.
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