What a Markham roof produces in a year
The planning figure for Markham is about 1,162 kWh a year for each kilowatt of panel capacity installed. It is an annual average covering the whole calendar, including the winter weeks when panels are under snow, so it belongs next to a year of consumption rather than a single month's bill. Multiply it by the size of the array in a quote and you have the production number that quote is built on.
What moves the result from there is your own roof: the share of it that faces south, what shades it and at what hours, and the pitch the panels sit at. Panel brand choice matters far less than those three. A production estimate made without a site visit or a proper shade study is a starting point, not a commitment, and it is fair to ask which one you are being shown.
The practical ceiling on size is 12 kW, the band Alectra treats as a Micro Generator connection. Most homes hit a lower limit first, either from usable roof area or from their own consumption, since Ontario credits exported electricity rather than buying it.
How Alectra connects a Markham solar system
Alectra Utilities treats residential solar of 12 kW or less as a Micro Generator connection, and the path has a fixed order: a preliminary consultation, a Form C application, an Offer to Connect, an ESA-inspected installation, then a bidirectional meter swap. The meter change is the final step, which is why a completed array is not the same thing as a live one, and why the gap between the crew leaving and the system exporting catches homeowners off guard.
Surplus generation earns a bill credit rather than a cash payment, and unused credits expire after 12 consecutive months under Ontario Regulation 541/05. Read that as a rolling one year bank: summer output offsets winter draw, but anything you bank beyond a year of your own consumption simply lapses unused.
That expiry is the reason a good quote starts with your bills rather than your roof. The seasonal shape of your consumption matters as much as the annual total, because a credit earned in July has to be spent within the following twelve months to be worth anything at all.
Markham's housing mix and roof shading
Per the 2021 census, single-detached houses make up about 56% of Markham's dwellings, apartments in buildings of five or more storeys about 16%, row houses about 14%, semi-detached houses about 6%, and duplex apartments about 5%. Most homes here therefore give an installer a full roof to design around.
Shading is where Markham splits in two. The newer subdivisions were built under current setback and shadowing rules and tend to have less roof shading than the older heritage village cores, where mature streetscapes and closer building patterns can put a neighbour's roofline or a tree line across your array for part of the afternoon. Shade is punishing in a way that surprises people: a partial shadow across an array costs more output than the shaded fraction alone suggests, which is why the shade study is the part of a site visit worth asking to see.
Type still shapes the design. Row houses often have a narrower south-facing roof plane that limits system size, and semi-detached homes and duplex apartments usually still allow an individual install but involve a shared roofline that the layout has to respect. Apartments in taller buildings need condo corporation or landlord approval rather than an individual permit, so that decision starts with the building.
Four heritage districts, and what they require
Markham has four designated heritage conservation districts: Thornhill, Markham Village, Buttonville and Unionville. If your property sits in one of them, you need a Minor or Major Heritage Permit for any exterior alteration, including a visible rooftop solar array, before work can proceed.
The ordering is the practical point. Heritage approval comes before the work, so a design commissioned without checking designation status may have to be reworked, and the placement of panels relative to the street-facing elevation is exactly what such a review considers. If you live in or near one of the four districts, confirm your property's status with the city before you pay for drawings.
Outside those districts, the approvals chain is simpler, but it is still worth confirming with the city what a rooftop solar installation requires at your address before you sign anything. The ESA inspection built into Alectra's connection process applies either way.
Programs, thresholds and what has closed
A regulatory change has widened the simplified path. As of May 1, 2026 the Ontario Energy Board raised the micro-embedded generation threshold from 10 kW to 12 kW, so more residential systems now qualify for the streamlined connection process, and that 12 kW line is the same one Alectra uses for a Micro Generator connection. For a city with a lot of larger detached homes, that is a meaningful widening.
On rebates, the live provincial program is Ontario's Home Renovation Savings Program, launched in January 2025, with a 2026-27 program year running from April 1, 2026 to March 31, 2027 and combined rebates of up to $10,000 for solar PV paired with battery storage. Its condition deserves as much attention as its ceiling: homeowners taking the HRSP solar incentive are generally directed to a load-displacement configuration rather than full net metering, so confirm the current rules with your installer before applying, since it can change how your exports are handled.
Federal programs have narrowed. The Canada Greener Homes Loan, interest-free up to $40,000, stopped accepting new applications on October 2, 2025, and only previously approved loans are still being funded. Its replacement, the Canada Greener Homes Affordability Program, launched in September 2025 and delivers no-cost retrofits through participating provinces, which do not currently include Ontario, for low to median income households, with solar federally eligible but each province setting its own technology list. Canada has no federal investment tax credit for residential solar, so treat any quote that assumes one as out of date.