How to Choose a Solar Installer in Ontario

A solar system is a 25-year commitment, and the installer you choose affects not just the price but how well the system performs, how your roof holds up and how smoothly the approvals go. Ontario has many capable solar companies, but also some that oversell production, underprice to win contracts, or disappear before the warranty does.

This guide sets out what to check, how to compare quotes on equal terms and which warning signs should make you walk away.

Step 1: Check credentials

At minimum, the company doing your installation should be able to show:

• An ESA/ECRA Licensed Electrical Contractor licence. In Ontario, electrical work for hire, including solar and batteries, must be done by a Licensed Electrical Contractor who takes out an Electrical Safety Authority permit. You can verify a contractor's licence through esasafe.com (opens in a new tab).
• Liability insurance and WSIB coverage. Ask for certificates. Roof work is high-risk, and you do not want an uninsured injury on your property.
• A track record. Ask how many residential systems they have installed in Ontario and request two or three references from jobs completed at least two years ago.
• Who actually does the work. Many solar firms subcontract installation. That is not necessarily a problem, but you should know who will be on your roof, who pulls the ESA permit and who handles warranty calls.

Industry certifications, such as solar-specific training from a recognized body, are a plus but not a substitute for the licence and insurance.

Step 2: Get comparable quotes

Request at least three quotes, each based on a site visit (or high-resolution satellite and shading analysis) and on your last 12 months of electricity bills. Ask every installer to include the same items so you can compare them properly.

Quote item	What to look for
System size (kW DC)	Sized to your annual use, not just to fill the roof
Price and cost per watt	Typical 2026 range roughly $2.50–$3.50/W before incentives
Panel make, model, wattage	Tier-one manufacturer with Canadian distribution
Inverter type and model	String, string with optimizers, or microinverters
Racking and attachments	Flashed mounts suited to your roof type and local snow loads
Annual production estimate (kWh)	Shading loss and assumptions stated
Electrical work	Panel upgrade, if needed, priced separately
Permits and approvals	ESA, LDC connection, building permit if required
Monitoring	App or web portal included, with any subscription fees
Warranties	Product, performance, inverter, workmanship and roof
Payment schedule	Deposit size and milestones
Timeline	Estimated weeks to installation and to permission to operate

Divide each total price by the system size in watts to get the cost per watt. A quote far below the pack may have cut corners on equipment, labour or approvals. One far above should explain what you get for the premium.

Step 3: Test the production estimate

The production estimate is the number your savings depend on. For an unshaded, south-facing array in southern Ontario, a reasonable specific yield is roughly 1,100–1,250 kWh per kW per year; east- and west-facing arrays produce roughly 85–90% of that, and shade reduces it further.

Questions to ask:

• What software and weather data did you use?
• What shading loss did you assume for each roof face?
• Does the estimate include inverter, wiring and snow losses?
• What is the year-one figure, and what degradation rate do you assume?

If one installer projects 1,400 kWh/kW for a partly shaded east roof while others say 1,000, the high number is a red flag, not a bargain. Cross-check with our solar savings calculator.

Step 4: Compare warranties

Warranty	Typical in 2026	Notes
Panel product	12–25 years	Covers manufacturing defects
Panel performance	25–30 years	Typically guarantees about 80–90% of rated output at the end
Inverter	10–25 years	Microinverters often longer than string inverters
Battery (if any)	About 10 years	Usually with a minimum remaining capacity
Installer workmanship	5–25 years	Look for at least 10
Roof penetrations	Should match workmanship term	Ask who fixes leaks and how quickly

A manufacturer's warranty is only as useful as the process to claim it. Ask who handles labour for removing and replacing a failed panel or inverter, and whether that labour is covered.

Step 5: Read the contract carefully

Before signing, make sure the contract includes:

• The exact equipment list, with substitution only by written agreement for equal or better equipment.
• A total price, a clear description of what could change it and how change orders are approved.
• Who applies for net metering or any rebate, and what happens to your deposit if approvals are denied.
• The production estimate attached as a schedule.
• A modest deposit. Large upfront payments before equipment arrives increase your risk.
• Clean-up, damage repair and roof-penetration responsibilities.
• Any financing terms, including interest, fees and whether any lien or registration on title is involved.

Caution: If a rebate is part of the deal, make sure the installer explains the net metering trade-off in writing. According to Home Renovation Savings Program rules published in 2026, systems receiving the solar + battery rebate cannot use net metering for the life of the system. See solar rebate vs. net metering and confirm terms on saveonenergy.ca (opens in a new tab).

Red flags

• "Free solar" or "government solar program" pitches. The microFIT feed-in tariff closed in 2017, and the Canada Greener Homes Grant and Loan are closed to new applicants. Companies that use names sounding like a government agency or utility deserve extra scrutiny.
• High-pressure, same-day discounts or reluctance to leave a written quote.
• Production estimates well above other quotes or that do not mention shading.
• No ESA permit mentioned, or suggestions that permits are unnecessary.
• Unsolicited door-to-door approaches. Ontario's Consumer Protection Act includes protections for direct agreements, including a 10-day cooling-off period. Verify the current rules on ontario.ca (opens in a new tab) and read our guide to door-to-door energy scams.
• Very large deposits or requests for payment in full before installation.
• Vague equipment descriptions such as "premium panels" without make and model.

After installation

Keep a file with the contract, the final equipment list, the ESA certificate of inspection, your LDC connection or net metering agreement, warranty registrations and monitoring login details. Check your monitoring app monthly for the first year and compare production with the estimate. A shortfall of more than about 10% over a full year is worth raising with the installer.

Frequently asked questions

How many quotes should I get?

Three is a sensible minimum. More can help if the first quotes differ widely in price or production estimates. Make sure each one covers the same items so you are comparing like with like.

Should I choose a local installer or a large national company?

Either can be good. Local firms may offer more responsive service; larger firms may have more financial stability. What matters most is licensing, insurance, a strong workmanship warranty and evidence that the company will be around to honour it.

Is the cheapest quote a bad sign?

Not necessarily, but compare the equipment, the warranty terms and what is excluded. A low price that leaves out a needed panel upgrade or the ESA permit is not actually cheaper.

Who handles the net metering application?

Usually the installer prepares and submits it on your behalf, but the agreement is between you and your LDC. Confirm in writing who is responsible and keep copies of everything submitted.