What does a 10kW solar panel installation cost in Markham?

I'd be glad to help scope out a solar project. For a system that size, I'll need a few details about your home and your goals to build an accurate estimate.

Question: What is your Forward Sortation Area (FSA)?

Question: When you say "10k," do you mean a 10kW (kilowatt) capacity system or a $10,000 budget?

• 10kW Capacity
• $10,000 Budget

Question: What's your current roof material, and roughly how old is it?

Question: Do you want to include battery storage (like a Tesla Powerwall), or just a grid-tied system?

• Grid-tied only
• Grid-tied + Battery Storage
• Off-grid

Question: Do you know the amperage of your main electrical panel?

• 100 Amp
• 200 Amp
• 400 Amp
• I'm not sure

Photos that would help A few photos would help confirm your roof and electrical system are solar-ready:

• Roof Overview: a clear shot of the roof faces where the panels would go.
• Electrical Panel: an overview of your main breaker panel, plus a close-up of the labels/directory.
• Utility Meter: your outdoor electric meter and where the power enters the house.

An FSA is simply the first three characters of your Canadian postal code (like M5V or L3R). It tells me your local utility and the permit rules for your area.

I've set your project to 10kW capacity on a 100 Amp panel. One thing to flag: a 10kW system produces a lot of power — usually more than electrical code lets a standard 100 Amp panel carry. We'll most likely need a panel upgrade to make it work.

Question: What are the first three characters of your postal code?

Question: Roughly how old is your shingle roof?

• 0-5 years
• 6-10 years
• 11-15 years
• 15+ years
• I'm not sure

Question: Would you like the estimate to include an upgrade to a 200 Amp panel?

• Yes, include the upgrade
• No, I want to see if there's another way

Photos that would help If you get a moment, a photo of your electrical panel (door open so I can see the breakers) would really help confirm what's needed for the 10kW connection.

Thanks for that. Since you're in Markham (L3R), your utility is Alectra Utilities.

For a 10kW system on a 100 Amp panel, the "other way" usually means a line-side tap (tying the solar in ahead of your main breaker) or derating the main breaker if your home's electrical load allows. I've added those steps to the plan.

The bigger "readiness" issue is the roof. Solar panels are meant to stay up for 25 to 30 years. Your shingles are already 11–15 years old, so they've probably got only 5–10 years left. If the roof fails with panels on it, you'd pay a contractor thousands just to remove and reinstall them around the roof repair.

Question: Since your roof is 11-15 years old, would you like to include a price for stripping and re-shingling it before the solar goes on?

• Yes, include a roof replacement in the estimate
• No, I'll take the risk with the current roof

Question: Do you have a preferred spot for the inverter (e.g., in the garage near the panel, or outside on the house)?

• Inside (Garage/Utility room)
• Outside (Near the meter)
• I'm not sure

Photos that would help A photo of your main electrical panel (door open) and the area around your utility meter would help a lot — it lets a contractor see whether a line-side tap is physically possible in your setup.

Here's the estimate plan

Work Summary

The client wants a 10kW solar install on an 11-15 year old shingle roof. The system is grid-tied with no battery storage, and the inverter mounts outdoors. To skip a full 200A panel upgrade, the tie-in uses a line-side tap or breaker derate on the existing 100A service. Alectra Utilities net-metering coordination is required.

Required Permits

Permit / Inspection	Owner	Reason
Electrical permit	electrician	Required for all new solar installations and service connections.
Alectra Utilities Net Metering Application	electrician	Required to tie solar into the grid and earn credits in Ontario.

Bill of Process

Step	Owner	Description
BOP-01	electrician	Apply for the electrical and building permits, coordinate the structural review, and file the Alectra Utilities Net Metering application.
BOP-02	structural_engineer	Assess the roof structure for the solar array load and provide stamped drawings/report.
BOP-03	solar_installer	Install roof attachments and the racking system on the existing asphalt shingles.
BOP-04	solar_installer	Mount the 10kW array and install the exterior-rated inverter near the meter.
BOP-05	inspector	Carry out the rough-in electrical inspection of DC wiring, grounding, and conduit.
BOP-06	electrician	Perform the line-side tap or main breaker derate to tie solar into the 100A service without a full panel upgrade.
BOP-07	electrician	Install the exterior AC disconnect as required by Alectra Utilities.
BOP-08	inspector	Carry out the final electrical and building inspections and coordinate utility commissioning for net metering.

Cost Estimate

Title	Description	Range
Permit & Utility Administration	Prepare and submit the electrical permit application and the Alectra Utilities Net Metering application, and coordinate the utility requirements for the grid-tie connection.	$1,045 - $1,645
Structural Engineering Review	Structural assessment of the existing roof framing to confirm load-bearing capacity for the array, with a stamped engineering report for building-permit compliance.	$1,400 - $2,100
Solar Racking & Roof Attachments	Install roof attachments and the racking system for the 10kW array, flashing every penetration on the existing asphalt shingles.	$2,855 - $4,435
Solar Array & Inverter Installation	Mount the 10kW array and install an exterior-rated string inverter near the utility meter, including DC string wiring and grounding.	$14,440 - $21,810
Electrical Service Integration (100A)	Perform a line-side tap or main breaker derate to fold the solar feed into the existing 100A service panel, including labeling and circuit protection.	$790 - $1,285
Exterior AC Disconnect	Install an exterior-rated AC disconnect between the inverter and service panel as required by Alectra Utilities safety standards.	$495 - $845
Inspection & Commissioning Coordination	Coordinate and attend the final electrical inspection, and manage the utility commissioning for Net Metering activation.	$220 - $370

Cost Breakdown

Category	Amount
Materials	$18,100 - $27,300
Labour	$3,280 - $5,015
Total	$21,375 - $32,215

Potential Additional Items

Description	Trade	Est. Cost	On-Site Trigger
Replacement of brittle asphalt shingles at attachment points if the existing roof won't reseal.	General Contractor	$350 - $550	Shingles crack or won't lift during flashing due to age (11-15 years).
Repair of localized roof deck rot found after pulling shingles for attachments.	General Contractor	$450 - $750	Soft or decayed wood found during racking installation.

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