What the satellite dish rule tells you to ask
Bylaw 422, the Zoning and Subdivision Control (Development) Bylaw, requires Development Permits in certain circumstances, with categories covering dwellings, detached garages, accessory buildings, fences, decks, pools and other structures. Solar is not among the named categories, which is a gap in the published record rather than an exemption.
The bylaw does contain one rule about mounted equipment, and it is instructive. A satellite dish greater than 0.61 m, roughly 2 feet, in diameter cannot be erected in any zone in the Town unless a special permit has been issued by the Development Officer. So Cornwall regulates exterior equipment by size, applies the rule town-wide rather than by zone, and routes the decision to a named officer.
That gives you a precise question to ask rather than a vague one. Ask the Development Officer whether a roof-mounted solar array is treated as a structure requiring a Development Permit, whether any size threshold applies to it as one does to satellite dishes, and whether the permit is an ordinary one or a special permit. Those three answers settle the municipal side.
Ask also about the other structures category, since that is the phrase most likely to capture a rooftop array if anything does. Get the answer by email if you can, and note who gave it and when, because in a town whose bylaw does not name solar, the response you were given is your documentation.
The Town publishes its decisions weekly. Use them
Cornwall publishes weekly the development permits that have been approved or denied. That is an unusually open practice and it is genuinely useful to a homeowner, because it converts a general question about what the Town allows into a record of what the Town has actually decided.
Before you apply, look through recent weeks for anything comparable to your project. If solar installations appear, you know the instrument used and that permits are being granted. If they do not appear at all, that is worth knowing too, and it is a good prompt for the call to the Development Officer.
It also gives you a fair way to test an installer. Someone who works in Cornwall should be able to point to a permit they obtained here. The published list means that claim is checkable rather than something you have to take on trust.
The provincial rebate is paused for new applicants
efficiencyPEI's Solar Electric Rebate Program paid 1,000 $ per kW DC installed, covering up to 40 percent of costs, to a maximum residential rebate of 10,000 $. It is paused for new applications after reaching capacity for the fiscal year, and existing pre-approval holders can continue.
On a residential system, up to 10,000 $ is a large share of the total, so any quote or payback estimate that assumes the rebate is currently overstating the outcome by up to that amount. Ask any installer whether their figure includes it, and ask for the same calculation without it.
The stated reason was capacity for the fiscal year rather than a decision to end the programme, so the practical question is timing rather than permanent loss. Ask efficiencyPEI what the current intake status is, whether new applications are expected to reopen, and exactly what a pre-approval is and whether you hold one. If the rebate is what makes your project viable, that answer is the project's critical path.
Maritime Electric, the agreement, and the December 31 reset
Maritime Electric is your provider. Net metering requires a renewable source such as solar or wind, generation exclusively for your own property, year-long billing with Maritime Electric, an application for and participation in a net metering agreement, adherence to the section 13 requirements in that agreement, and a generator no larger than 100 kW.
Ask for a copy of the agreement and read section 13 yourself. The programme names adherence to it as a requirement, which means it contains obligations you are agreeing to rather than background text, and a summary from a third party is not the same as the clause.
PEI net metering uses kilowatt hour credits rather than a cash feed-in tariff for households. Credits accumulate through the year and reset on December 31, with no cash payout for unused credits. Because that date falls at the end of the darkest quarter, a summer surplus has roughly half a year to be consumed before it is cleared, which a system matched to the household will generally manage and an oversized one will not.
So size to twelve months of your own kilowatt hour totals rather than to available roof area. A well oriented roof here produces about 1,105 kilowatt hours a year per kilowatt installed, and orientation and shading decide how close you get to it. Shading costs the most, because it removes production in the middle of the day.
What else is available
Federally the options 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.
The Canada Greener Homes Affordability Program replaced it in September 2025, delivering no-cost retrofits through provincial partners for low- to median-income households, with solar PV federally eligible but each province setting its own technology list. Check what Prince Edward Island has actually included rather than what the federal programme permits.
Canada has no federal investment tax credit for residential solar. So unless you hold a pre-approval or the provincial programme reopens, the honest arithmetic is the value of self-generated and credited electricity over time against the full installed cost with no rebate. Ask for the payback calculated that way, and settle the Development Officer's answer before committing to a system size.