How net metering works in Ontario

Each billing period your LDC reads two numbers: the kilowatt-hours you took from the grid and the kilowatt-hours your system sent into it. Section 8 of O. Reg. 541/05 values the exports on the same basis as the power you used, commodity included, and takes that value off every charge that depends on consumption. Charges that do not depend on consumption stay on the bill, whatever the panels made.

Hydro One's net metering page spells out the split. A credit can pay for the electricity itself, the distribution volume charge, transmission, variable rate riders, line losses and the wholesale market service rate. It cannot pay the monthly service charge, the smart meter entity charge, fixed rate riders or the standard supply service charge (read 2026-10-10).

The credit is a dollar amount. Hydro Ottawa's sample net metering bill builds it from credits on electricity, delivery and regulatory charges and shows the total as a Generation Credit Balance, which cannot be redeemed for cash or used to pay for other services. The regulation rules out paying it any other way (s. 8(15)).

Section 8(8) writes a balance down to $0 only when credits have been carried forward in every billing period of the previous 12 months. Hydro Ottawa's bill counts those periods as Cumulative Months of Generation and writes off the balance once the count reaches 12. A month in which your use draws the balance to zero restarts the count, and nothing is lost.

Ottawa's seasons decide which side of that line you land on. In Natural Resources Canada's data for Ottawa, a south-facing array at latitude tilt makes 722 kWh per kW from March to August and 479 from September to February, and November is the weakest month at 57 (NRCan, read 2026-10-10). Credit builds through spring and summer and is spent through the dark months. Size the array to a year of your use and winter spends it. Size it well past that and the surplus goes to the LDC's account every year (s. 8(13)).

Two other events clear a balance: the final bill when an account closes, as when you sell the house, and the end of the net metering agreement (s. 8(12)). You can cancel the agreement at any time on 90 days' written notice, but you cannot be net-metered again for 12 months after (s. 9).

A net-metered home or small business picks a price plan like any other customer, and the LDC prices both the power you use and the credit you earn on that plan. Hydro One says so on its net metering page, and Hydro Ottawa's sample bill lists a separate credit for each Time-of-Use and Ultra-Low Overnight period. The prices below are the Ontario Energy Board's, set for 2025-11-01. The OEB sets new ones every November 1.

Sections 6 to 7.1 of the regulation set the tests, and they are short.

On 2026-05-01 the Ontario Energy Board raised the ceiling for micro-embedded generation in its Distribution System Code from 10 kW to 12 kW. The same amendments exempt residential customers from the commercial insurance requirement in the connection agreement (OEB notice of amendments, 2025-12-18). For most homes, 12 kW is the line that matters.

At 12 kW AC or less, Hydro Ottawa sends a Service Layout within 15 days of a service request, or up to 60 for complex projects, when the feeder has room, and the layout stays valid for 90 days. Above 12 kW the request starts with a Preliminary Consultation and moves to a Connection Impact Assessment on drawings stamped by an Ontario professional engineer. Hydro One splits its forms on the same line: Form C for 12 kW or less, Form B above it. Fees vary with system size.

Feeder capacity is the one limit a design cannot move. Under the Distribution System Code an LDC must accept net metering applications only until net-metered generation reaches 1% of its three-year average annual peak load. Six distributors were past that line in 2024, and the OEB has proposed raising it to 2% (report to the Minister, March 2026). Hydro Ottawa publishes a list of feeders that cannot host new generation of any size, and for a system of 12 kW or less it invites a service request to look for another way to connect.

From ontario.ca, the OEB, the City of Ottawa and the two utilities' process pages, read 2026-10-10.

For most homes with a usable roof, yes, by The Atmospheric Fund's analysis. The regional climate agency estimated on 2026-07-10 that a 10 kW net-metered system pays back in roughly half the time of a comparable system without net metering, rebate included. It found the rebate can come out ahead for a home with little roof space that wants a battery.

The rebate is the alternative, and Ontario makes you pick one per system. Home Renovation Savings pays $1,000 per kW of panels up to $5,000 and $300 per kWh of battery up to $5,000, each capped at half the eligible cost, with HST left out of that cost. The money is only for a first rooftop system used for load displacement, and the program names ground-mounted solar as ineligible (Solar and Storage Program Stream Requirements, version October 2025, read 2026-10-10).

Net metering pays nothing upfront and credits every exported kWh for as long as the agreement runs. Our Orléans install was built for it: 26 panels and 10 MWh a year, by its video overlay.

Four limits shape a net-metered design, and each has a known answer.

Not as of 2026-10-10. The last amendment to O. Reg. 541/05, O. Reg. 386/22, took effect on 2022-07-01, and e-Laws shows that version as current to 2026-10-07. The change so far is a recommendation. In its March 2026 report to the Minister of Energy and Mines, released 2026-09-02, the Ontario Energy Board recommended moving from net metering to net billing, which would pay for exported power through a tariff set by the time and place it enters the grid.

The same report says a transition should consider a legacy provision for existing net-metered customers, to account for the payback of systems already installed, with adequate notice of any change. It put net metering's adoption rate below one percent. The recommendation is addressed to the Ministry, which sets the net metering rules.

On net metering, panels come first. The grid already holds your summer surplus as a credit for up to 12 months, so a battery is not needed to keep that value. A battery is worth adding for backup: the Canadian Renewable Energy Association notes that panels will not power a building during an outage unless storage is attached. It also lets the house use its own solar in the evening, which counts most in Ultra-Low Overnight's 39.1¢ hours.

Net metering accepts a battery paired with solar. The rebate is narrower: Home Renovation Savings pays for a battery only when it is paired with a new solar system sized for it. Sizing and backup circuits are on our solar battery storage page.

The same regulation covers a business, a farm or an institution, and the same 12 kW line decides the connection route. One difference shows on a demand-billed account: credits are worked out on kWh, so they do not offset charges billed on peak kW (Hydro One; O. Reg. 541/05, s. 8).

Net metering has no mounting rule, so a ground mount or a solar carport can be net-metered where the incentive programs draw lines. Home Renovation Savings excludes ground-mounted solar, and Save on Energy's Retrofit incentive covers only rooftops and parking canopies. Sharing one array's credits across several accounts, called community net metering, exists only as a demonstration project, and the OEB has recommended opening it up. Larger systems are on our commercial solar page.