What a Peterborough roof produces in a year
Peterborough's modelled yield is about 1,182 kWh a year for each kW of capacity installed, from Natural Resources Canada's photovoltaic potential data. On that basis a 7 kW array models at roughly 8,300 kWh a year, a 10 kW array at roughly 11,800 kWh, and a system at the 12 kW MicroDER ceiling at roughly 14,200 kWh. Those figures assume a south-facing, unshaded roof at a sensible pitch, so read them as the best case for your address.
What pulls a real install below that is predictable: orientation, pitch and shade. East and west facing planes give up output across the year, and an obstruction that clips the array for a couple of hours each afternoon takes a bite out of every sunny day. Ask for a shading assessment on your own roof and compare quotes on modelled annual kWh, not on panel count.
Hydro One bills residential customers on time-of-use pricing, so the value of your production depends partly on when it happens. Anything you consume in the same moment you generate it never becomes an export and never becomes a billed import, which sidesteps the credit system entirely. That is the argument for moving heavy loads into daylight hours, and the argument for storage if your consumption is concentrated in the evening.
How Hydro One credits your surplus generation
Hydro One credits net metering customers for the surplus electricity they send to the grid, and Ontario values that surplus kWh for kWh at the retail electricity rate rather than at a discounted export price. Those credits carry forward for up to 12 consecutive months and then expire, and Ontario pays no cash for net annual excess generation.
That combination sets a practical ceiling on system size that has nothing to do with roof area. A system that banks a large summer surplus you cannot draw down within a year is producing credits that will expire unused. The sensible target is your household's annual consumption, and if you are planning to add an electric vehicle or a heat pump within the next few years, it is cheaper to size for that consumption now than to return and expand the array later, since expanding also means going back through the connection process.
Capacity checks, the Offer to Connect and your budget
Residential systems of 12 kW or less go through Hydro One's MicroDER process. You submit a Form C application, Hydro One checks it against its Station and Feeder Capacity Calculator, and then issues an Offer to Connect before any work begins. That last part is not a formality: the Offer to Connect is the gate, and starting an install before it lands is how homeowners end up paying for equipment they cannot energise.
The capacity check is the piece that makes Peterborough different from a city on a municipal distribution system. Connection costs vary with the available capacity of the local transformer serving your property, so the number is site-specific rather than a standard fee. A quote that assumes a typical connection cost is guessing until the application comes back. Get the Form C in early, because the answer affects both your budget and whether the system size you were quoted is the one you can actually build.
The 12 kW threshold changed recently. On May 1, 2026 the Ontario Energy Board raised the simplified micro embedded generation limit from 10 kW to 12 kW, so more full-size residential systems now qualify for the streamlined route. Anything above 12 kW moves onto a different connection path, which is worth asking about before you agree to a larger design.
Heritage designation in Peterborough, and what is not designated
Most Peterborough homes are freehold, so the constraint to check is heritage designation rather than a homeowners association. The Avenues and Neighbourhood, designated in 2016, is the city's only current Heritage Conservation District. If your address falls inside it, expect the alteration rules that come with designation to apply to visible exterior work.
A downtown Heritage Conservation District has been talked about, but it is still at the study stage and has not been designated, so it does not yet impose alteration rules on properties inside the study area. That distinction matters when you are getting advice: a study area is not a designated district, and someone telling you that downtown Peterborough is off limits for rooftop solar is describing a proposal rather than the current rules. Confirm your own address against the designated district rather than relying on a general impression of the neighbourhood.
What Peterborough's housing mix means for your roof
Peterborough's housing stock is majority single-detached: about 57% of dwellings per the 2021 census, spread across areas including Otonabee, Monaghan, Town, Ashburnham and Northcrest. For those owners the roof is a private asset with a single decision-maker, and there is usually enough continuous plane to design a full-size array rather than a fragmented one.
The apartment picture is a bigger part of the story here than the detached share alone suggests. Apartments in buildings under five storeys are about 18% of dwellings, which is unusually common, and apartments in buildings of five storeys or more add about 7%. Row houses are about 8%, and apartments or flats in a duplex about 7% more. In every one of those cases the roof is controlled by a landlord or a corporation rather than the occupant, so approval has to come from the property owner.
That has a practical upside worth naming. The compact, low-rise apartment stock in and around downtown means a real base of landlord-controlled roofs, which are exactly the roofs where a single owner can make a decision covering several units at once. If you rent, the conversation to have is with your landlord, not with an installer.
Rebates and financing for Peterborough homeowners
Ontario's Home Renovation Savings Program is the main residential incentive available here. It launched in January 2025 and was expanded for the 2026-27 program year, which runs April 1, 2026 to March 31, 2027, offering combined rebates of up to $10,000 for solar PV paired with battery storage. Because Peterborough's connection cost is site-specific rather than fixed, budget the rebate and the connection cost as separate lines: one is known in advance, the other is not known until Hydro One responds to your Form C.
There is also a configuration question. Homeowners taking the HRSP solar incentive are generally directed to a load displacement setup rather than full net metering, so the rebate and the Hydro One credit arrangement described above are not automatically the same project. Ask your installer which route they intend to apply under and confirm the current rules before anything is submitted.
Federal programs offer less than most people expect. The interest-free Canada Greener Homes Loan of up to $40,000 stopped accepting new applications on October 2, 2025 and now funds only previously approved loans. The Canada Greener Homes Affordability Program replaced it in September 2025, delivering no-cost retrofits through participating provinces, which do not currently include Ontario, for low- to median-income households, with solar PV federally eligible but each province setting its own technology list. Canada has no federal investment tax credit for residential solar. Some Ontario municipalities and utilities also run occasional financing such as local improvement charges or on-bill repayment, and availability shifts, so ask what is currently open while you are gathering quotes.