Ontario net metering calculator
Net metering in Ontario is a seasonal machine, not an annual sum. Credits build through the summer, get spent through the winter, and anything left twelve months after it was earned is reduced to zero. This runs the balance month by month so you can see the shape rather than a single number that hides it.
Last updated By The SolarPanelFinder Rooftop Desk
Credits through a full year
Over the first twelve months, from a zero balance in January
1,302 kWh exported, 316 kWh still bought
The array generates 9,296 kWh against the 9,000 kWh your home uses. 7,994 kWh of that is consumed the moment it is made and never touches the grid, which is the part worth full value without any credit mechanism at all.
- Credit balance at its highest, in September
- 1,302 kWh ($156)
- Credit still unused when the twelve months are up
- 612 kWh ($73)
- Electricity you no longer buy, valued at 12cOntario Energy Board, Electricity rates
- $1,042
Month by month, and this is the shape that decides it
The bar is what the array makes that month. The next column is what goes out to the grid or comes back from it. The last is credit carried forward.
| Month | Generated | In or out | Credit carried |
|---|---|---|---|
| Jan | 528 kWh | in 222 kWh | 0 kWh |
| Feb | 656 kWh | in 94 kWh | 0 kWh |
| Mar | 872 kWh | out 122 kWh | 122 kWh |
| Apr | 904 kWh | out 154 kWh | 276 kWh |
| May | 976 kWh | out 226 kWh | 502 kWh |
| Jun | 984 kWh | out 234 kWh | 736 kWh |
| Jul | 1,024 kWh | out 274 kWh | 1,010 kWh |
| Aug | 968 kWh | out 218 kWh | 1,228 kWh |
| Sep | 824 kWh | out 74 kWh | 1,302 kWh |
| Oct | 712 kWh | in 38 kWh | 1,264 kWh |
| Nov | 440 kWh | in 310 kWh | 954 kWh |
| Dec | 408 kWh | in 342 kWh | 612 kWh |
Two things this model simplifies, said plainly rather than buried. Your consumption is spread evenly across the year, because no source publishes a monthly shape for Ontario households; real homes use more in January and August, which makes the seasonal mismatch worse than shown here, not better. And the year starts from a zero balance, as a system commissioned in January would. In later years the December balance carries into January, subject to the twelve-month rule. Natural Resources Canada also cautions that its monthly figures are indicative and do not account for snow cover or an unusually cloudy year.
A net metering agreement and the provincial rebate are alternatives
You choose one route or the other, and this page models only the net metering one. The provincial program funds systems sized to displace what the home itself uses, and its requirements state that a system subject to a net metering agreement is not eligible for it. So the figures above assume you have gone the net metering way.
Which is worth more is genuinely a question about your own household rather than about which headline is larger. A home that consumes most of what it generates gets less from the credit mechanism and more from the other route; a home that exports a real surplus gets the opposite. Every condition on both is set out on our rebates and net metering page.
The method
Why a month-by-month model and not an annual one
An annual total hides the only thing that actually costs Ontario homeowners money here.
Almost every net metering estimate online works in annual totals: generation for the year, consumption for the year, subtract one from the other. That framing makes the twelve-month expiry invisible, because on an annual view a surplus just looks like a surplus. In reality the credit is earned in a particular month and dies twelve months later, so what matters is whether you have something to spend it on before then.
The seasonal swing is what makes this bite in Ontario. Natural Resources Canada publishes Toronto photovoltaic potential month by month, and the range is dramatic: 128 kWh per kW installed in July, 51 in December, 66 in January. A household's electricity use does not follow that curve. So the array runs a surplus from roughly March to September, banks it, and draws it down again through the autumn and winter. Where the balance sits at the twelve-month mark is what tells you whether the array is the right size.
Two simplifications are worth stating rather than hiding. Consumption is spread evenly across the twelve months here, because we could not find a published monthly consumption shape for Ontario households and we would rather assume flat and say so than model a curve nobody published. Real homes use more in January and more in August, both of which make the mismatch worse than the model shows. And the first year starts from a zero balance, as a system commissioned in January would; in steady state the December balance carries into the new year, still subject to the twelve-month rule.
One number in the result deserves more attention than it usually gets: the electricity consumed straight from the array, as it is generated. That portion never enters the credit system at all. It simply is not bought, at whatever your rate happens to be that hour, and it is immune to every rule above. It is usually the largest single component of what solar is worth to an Ontario household.
Frequently asked questions
How does net metering work in Ontario?
- When your panels make more than the house is using, the surplus goes onto your utility's grid and you get a credit on your electricity bill. When they make less, you draw from the grid and the credit is applied against what you owe. The Ontario Energy Board is precise about the limits: the credit can only offset charges related to the electricity you consumed, so it does not touch delivery charges, regulatory charges or taxes, and nobody sends you money. Every Ontario local distribution company is required to offer it.
Do net metering credits expire?
- Yes, and this is the rule most worth knowing before you size a system. Unused credits carry forward for up to twelve months and are then reduced to zero. That is why the calculator on this page runs a month-by-month balance instead of an annual total: it shows you the month your balance peaks and how much is still sitting there unused when the twelve months are up. Credit you never spend is generation you paid for and gave away.
Why does the credit balance rise all summer and fall all winter?
- Because Toronto's solar resource swings by a factor of two and a half across the year while a household's consumption does not. Natural Resources Canada publishes Toronto's monthly photovoltaic potential: 128 kWh per kW installed in July against 51 in December. So an array that comfortably covers a house in June leaves it buying electricity in January, and the credits banked over the summer are what carry it through. An array sized to break even in December would be enormously oversized for July.
Can I get the Ontario rebate and net metering together?
- No. You take one or the other. The provincial program funds systems designed for load displacement only, and its requirements state that systems subject to a net metering agreement are not eligible. Which route is worth more to you depends on your own consumption pattern rather than on which headline number looks bigger, and it deserves a page with every condition attached to it. Ours is the rebates and net metering page, linked below.
Is net metering the same as being paid for my power?
- No, and the difference matters. It is a credit against what you consume, applied to the consumption portion of your own bill. It is not income, the utility does not send you a cheque, and a credit balance is not money you can withdraw. Any quote or website describing net metering as getting paid for the electricity you send back is describing something Ontario does not offer.
What price should I put in the rate field?
- Whatever a kWh actually costs you, which is on your bill. The presets are the Ontario Energy Board's current regulated prices, in force from 1 November 2025 to 31 October 2026: 12.0 cents on Tier 1 tiered, 9.8 off-peak, 15.7 mid-peak and 20.3 on-peak under time-of-use. Those are the electricity line only. Your full bill also carries delivery, transmission and regulatory charges and the Ontario Electricity Rebate, and the OEB resets the regulated prices periodically, so treat any figure here as current rather than permanent.
Sources
Where these figures come from
- Ontario Energy Board, Net metering - what a credit may offset, and the twelve month expiry
- Ontario Energy Board, Electricity rates - the regulated prices in the rate presets, and their effective dates
- Natural Resources Canada, Photovoltaic potential and solar resource maps of Canada - Toronto generation month by month, and the caution about what monthly figures do not model
- Toronto Hydro, Net Metering Program - how the local connection process runs
Ask an installer which route they have assumed, then compare
This site does not take quote requests and passes nothing to anyone. Every profile shows the company's own phone number and website, so you contact whoever you want to, directly.