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Solar Grid Connection in Ontario (2026): Net Metering vs Load Displacement, Applying to the Utility First, ESA and Plan Review, the Panel and Backfeed Breaker, and Backup Power
Electrical & Lighting
Hooking Solar to an Ontario House: Ask the Utility First, Mind the Panel, and Do Not Expect Lights in a Blackout
Whether solar pays on your roof is a separate question, covered on the residential solar page. This page is about the wiring: which agreement with the utility you sign, what has to be approved before anyone buys panels, how the system ties into your electrical panel, and why a grid-tied system goes dark with everyone else unless it has a battery and the right inverter.
The numbers
12 kWHydro One Form C limit, and the ESA plan review threshold since July 6, 2026
12 monthsnet-metering credits carry forward
$5,000most the solar rebate pays, with no net metering
0 wattsfrom grid-tied solar in an outage, without a battery
| Electrical work solar can bring with it | Installed | Default or note |
|---|---|---|
| Panel replacement, same amperage, for spaces or a bigger busbar | $1,500 to $3,000 | $2,200 |
| 100 A to 200 A service, overhead | $2,500 to $5,000 | $3,800 |
| Meter base and mast replacement | $500 to $1,500 | the customer owns the meter base |
| Battery for backup, one Powerwall 3, 13.5 kWh | $15,500 to $24,000 | $19,000 |
| Battery, Enphase IQ 5P per 5 kWh module | about $4,400 to $4,500 | |
| Bi-directional meter | installed by the utility | net metering only |
October 2026 ranges from Ontario contractor and installer pages, before HST. The panels and inverter themselves are priced on the residential solar page; this table is only the electrical work that may come with them.
Why Ontario prices are all over the map: the electrical extras on a solar job were priced very differently by the people we checked. A same-size panel swap ran $800 to $2,500 at one Toronto contractor and $1,800 to $3,000 at another. One Powerwall 3 ran from $15,500 at a Toronto electrical contractor to $24,000 before HST at an Ontario solar installer. Some solar quotes fold the panel work and the paperwork in; some leave them for the electrician you have not met yet. Budget $2,200 for a panel swap if the busbar is too small, and get two or three quotes on the same written scope.
Net Metering or Load Displacement: Pick Before You Buy
There are two ways to tie solar to an Ontario house. Under net metering, the utility puts in a bi-directional meter, what you send out is credited against what you take in, and on Hydro One excess credits carry forward for 12 months. Under load displacement, the system only feeds the house’s own use and does not sell to the grid.
The choice is not just technical. A homeowner who takes the Home Renovation Savings solar rebate, $1,000 per kW up to $5,000 and at most 50 percent of the cost, cannot sign a net-metering agreement: the system must be load displacement, used for the home’s own consumption. An 8 kW system would earn $8,000 at the per-kW rate, so it hits the $5,000 cap. Owner-occupied houses only, and you need written pre-approval from the program and your utility before buying. The Home Renovation Savings page has the program rules.
Nobody can tell you which is better for your house without your bills, and that is the solar page’s job. What this page can tell you is that you pick one, in writing, before the installer orders anything.
The Order of Things
- Apply to your utility first. Hydro One’s own page cautions applicants not to incur any expenses until it approves the connection. Systems of 12 kW or less use its Form C. Other utilities, Alectra, EPCOR in Collingwood, the small ones, have their own forms; EPCOR’s process starts with a capacity check and a single line diagram.
- Get the rebate pre-approval, if you want the rebate. In writing, from the program and the utility, before buying.
- The ESA notification. A Licensed Electrical Contractor files it before the electrical work starts, and ESA inspects. ESA plan review applies to some generation installations; the threshold moved from 10 kW to 12 kW on July 6, 2026, so ask your installer whether yours needs it. A building permit for the roof, where your township wants one, is a separate thing; the ESA permit page explains the difference.
- The utility connects. Under net metering it installs the bi-directional meter. Some utilities book a disconnect, inspect and reconnect visit.
Do those in a different order and you can own a roof full of panels you are not allowed to turn on. That is a very expensive way to shade the shingles.
The Panel and the Backfeed Breaker
Most home solar connects through a breaker in your main panel, which means the panel’s busbar is now fed from two directions: the utility at the top and the solar at the breaker. A common rule of thumb is that the main breaker plus the solar breaker should not add up to more than about 120 percent of the busbar’s rating, with the solar breaker at the far end from the main. That is a rule of thumb, not a quote from the code. Your electrician and ESA make the call on your panel.
On a 200 A panel with a 200 A main, 120 percent is 240 A, which leaves room for a 40 A solar breaker; sized at 125 percent of the inverter’s continuous output, that suits about 32 A, roughly 7.7 kW. On a 100 A panel with a 100 A main, the room is 20 A, about 16 A of inverter output, roughly 3.8 kW.
If the system is bigger than the panel can take, the usual fixes are a new panel with a heavier busbar, a smaller main breaker if the load calculation allows it, or a connection on the supply side of the main. Each is a design decision by the electrician, and the first one is where the $1,500 to $3,000 panel line comes from. A full panel is a separate problem; the subpanel vs service upgrade page sorts spaces from capacity, and the panel upgrade cost page prices the upgrade.
Why Solar Goes Dark in an Outage
A grid-tied inverter shuts itself off when the grid goes down. It has to: otherwise it would feed the line the crew is working on. So a house with solar and no battery is dark in an outage, at noon in July, with the sun shining on 20 panels. People find this out during their first storm and are not pleased.
For backup, you need a battery and an inverter or gateway that can disconnect the house from the grid and run it on its own. That is a different product from a plain grid-tied inverter, so it has to be decided before purchase. A battery paired with new solar can earn the Home Renovation Savings battery rebate, $300 per kWh up to $5,000, at most 50 percent of the cost, with the same no-net-metering rule; one 13.5 kWh battery works out to $4,050. It does not come off the price; count it when it is paid, not before. Whether a battery or a generator suits your house better is on the generator vs battery page.
Questions people ask
Do I need permission to connect solar to the grid in Ontario?
Yes. Apply to your local utility and get approval before spending money; Hydro One uses Form C for systems of 12 kW or less. The electrical work needs an ESA notification filed by a Licensed Electrical Contractor, or by you in your own home.
Can I get the solar rebate and net metering?
No. Home Renovation Savings participants cannot sign a net-metering agreement; the system must be load displacement for the home’s own use. Choose one before you buy.
Will my solar panels work in a power outage?
Not without a battery and an inverter or gateway built to run the house off the grid. A plain grid-tied inverter shuts off when the grid does, for the line crew’s safety.
Do I need a new panel for solar?
Sometimes. If the main breaker plus the solar breaker comes to more than about 120 percent of the busbar’s rating, the usual rule of thumb, the electrician may replace the panel, change the main, or connect on the supply side. A same-amperage panel replacement is $1,500 to $3,000.
Check your service before you sign for panels
The electrical service capacity calculator runs the code’s load arithmetic on your house, so you know whether the panel and service have room before the solar company tells you. If the solar quote includes panel or service work, the $99 review reads it, and up to two others, and tells you what is in and what is not.
Sources and further reading
- Hydro One net metering: applying before you spend money, Form C for systems of 12 kW or less, and how credits carry forward.
- Home Renovation Savings: solar and battery storage: the per-kW and per-kWh rebates, the pairing rule for batteries, pre-approval and the net-metering exclusion.
- ESA notifications and inspections: when a notification of work is needed, who files it, and the rule that nothing is covered until an inspector authorizes it.
