Aerial view of a Terawatt Solar rooftop installation on a GTA home Solar panel system design blueprint used in a Terawatt Solar Ontario solar company proposal
Solar Company Ontario

Compare Energy Saving Programs with Ontario's Longest Standing Solar Company.

Ontario's in-house solar design and installation crew, serving Toronto, Markham, Mississauga, Brampton, Vaughan, Oakville, Burlington, Hamilton and Kitchener.

Terawatt Solar is one of Ontario's longest-running residential and commercial solar installers, working from our Markham office at 7030 Woodbine Ave. Every installation is completed by our own ECRA/ESA-licensed Master Electrician and crew, with no subcontractors on your roof. Every proposal is built from your actual utility billing and roof data, so you can compare real payback, savings and rebate options before you commit.

(877) 648-3323 Get Your Real Numbers
Aerial view of a completed Terawatt Solar rooftop installation with the branded Terawatt Solar service van on site
Real Terawatt Solar installBranded crew, branded van, no subcontractors on your roof
Terawatt Solar is a BBB Accredited Business with an A+ Rating Terawatt Solar 5-star Google customer reviews in the Greater Toronto Area SolarEdge inverter equipment installed by Terawatt Solar, Ontario solar company Canadian Solar panels installed by Terawatt Solar across the GTA
Licensed & Insured 8-Year Workmanship Warranty, 25-Year Panel Warranty Free On-Site Assessment In-House Permitting & Interconnection, No Subcontractors Serving The GTA And Ontario From Our Markham Office One Of Ontario's Longest-Running Solar Installers
What It Actually Costs

Average System Cost & Break-Even For GTA Homes

Figures below reflect a typical 9 kW residential solar system sized for an average Greater Toronto Area home on time-of-use billing. Your exact numbers depend on your roof, usage, municipality, and whether you take the provincial solar rebate or keep net metering, run your own numbers on our solar calculator or request a free assessment.

9 kW
Average System Size
Our typical GTA residential install size
~$25,200
Typical Installed Cost
About $2.80 per watt CAD, before any rebate
Year 11
Average Break-Even
Net-metered scenario, point savings overtake cost
CUMULATIVE NET POSITION ($) YEARS SINCE INSTALLATION -$68k -$42k -$15k +$11k +$38k Yr 0Yr 5Yr 10Yr 15Yr 20Yr 25 BREAK-EVEN -$68k if you never go solar +$38k net position with solar
Cost of staying on grid power only
Net position with Terawatt solar
Break-even point

Illustrative estimate for a 9 kW net-metered residential system, based on Ontario time-of-use rates (roughly 20.3¢/kWh on-peak, 9.8¢/kWh off-peak) and an assumed average annual rate increase. Actual costs, production, and savings depend on your roof, shading, usage, financing, and whether you choose net metering or the provincial rebate route. Ask us for a figure specific to your home.

Aerial view of a Terawatt Solar rooftop installation in the Greater Toronto Area
Our Services

Residential, Commercial & Battery Solar Services Across Ontario

Whether you're a Markham homeowner trying to beat rising time-of-use rates or a Mississauga business evaluating a commercial rooftop array, our design team builds around your actual energy use, not a generic template, including ground mount solar for larger properties.

Residential Solar

Custom-sized rooftop systems built for your specific GTA home, your roof orientation, and your real hydro usage, not a satellite guess.

Residential Solar Installation GTA →

Commercial Solar

Rooftop, carport, and ground mount systems engineered for warehouses, retail plazas, and industrial sites across Toronto and the surrounding region.

Commercial Solar Ontario →

Battery Storage

Pair solar with battery storage for outage backup or to shift self-generated power into expensive on-peak evening hours instead of selling it back cheap.

Battery Storage Installation →
Choose Your Solar Path

Net Metering Or Load Displacement With Battery Backup

Every GTA proposal we write comes down to two real paths. We model both from your actual hydro bills in our solar calculator before you decide, because the better fit depends on your usage, your budget, and whether outage backup matters to you.

UTILITY GRID 1:1 CREDIT

Net Metering (Maximum Offset)

Your residential solar system is sized to offset close to 100% of your annual usage. Excess solar flows to the grid and earns 1:1 retail credit, which you draw down later, including through winter. Read more on how net metering works and our full incentives guide.

BATTERY BANK

Load Displacement + Battery (Grant + Resilience)

A smaller solar system sized to your daytime load, paired with a battery storage system, so solar powers your home directly and charges the battery for use after dark or during an outage. See the Home Renovation Savings Program rebate guide for current eligibility.

  • Investment: Lower upfront cost
  • How it works: Solar powers your home and charges the battery, stored energy used later
  • Incentives: HRSP rebate up to $10,000 applied immediately, but disqualifies net metering
  • Battery: Included, backup power during outages, for larger sites see commercial solar
  • Financing: Toronto homeowners can finance the balance with the HELP loan

We run the real numbers for both paths on every proposal, including 30-year savings, IRR, and effective cost per kWh versus your utility rate, so you're comparing two fully-costed scenarios, not guessing. Still deciding? Browse our case studies, net metering explainer, or see service areas across the GTA.

Your Savings At A Glance

Monthly, Annual & Lifetime Savings

Based on an average 9 kW net-metered residential system offsetting roughly 85 to 90% of a typical GTA home's electricity use on Ontario time-of-use pricing.

Aerial view of a Terawatt Solar rooftop installation in Mississauga, Ontario
~$1,380
Avg. Annual Savings
Savings PeriodEstimated AmountNotes
Monthly~$115Reduction in your average time-of-use hydro bill
Annual~$1,380Compounds as Ontario on-peak rates continue to rise
25-Year Lifetime~$38,000Net savings after system cost, net-metered scenario
Incentives & Programs We Check For Every GTA Client

Program terms change. We confirm current eligibility and run both scenarios below before you sign anything.

ProgramValueStatusNotes
Net Metering (Toronto Hydro & most GTA utilities)1:1 retail creditActiveAvailable to customers who don't take the HRSP solar rebate; see our Toronto Hydro guide
Home Renovation Savings Program (HRSP)Up to $10,000ActiveUp to $5,000 solar + $5,000 battery, stackable, but disqualifies net metering
Toronto Home Energy Loan Program (HELP)Property-tax-repaid financingActiveCity of Toronto PACE loan, stackable with HRSP; full details
Time-of-Use Rate Arbitrage~20.3¢ vs ~9.8¢/kWhActiveOn-peak to off-peak spread that makes solar plus battery more valuable
Federal Clean Technology ITC30% of system costActiveCommercial and business projects only, not residential; full details

Figures are non-binding estimates for an average 9 kW residential system based on current Ontario time-of-use pricing and active programs as of this writing. Your actual system size, cost, and savings depend on your roof, energy use, municipality, and which incentive path you choose. Request a free assessment for numbers specific to your home.

Terawatt Solar branded service van on a GTA driveway

Get The Numbers For Your Home

Send a recent hydro bill and we'll tell you your real offset percentage, system cost, and 25-year savings under both the net metering and rebate scenarios, not a generic estimate.

Book a Solar Discovery Call
Real Projects

See How Much Our Customers Save With Solar

Our focus is getting homeowners and businesses a fast return on investment against rising Ontario electricity rates. Read more about our in-house crews, decades of combined installation experience, and a Markham office you can actually visit, or browse the Terawatt Solar blog for deeper breakdowns on net metering, rebates, and roof suitability.

All Our Projects →
Aerial view of a Terawatt Solar rooftop installation, Mississauga, Ontario

Residential Install, Toronto Area

9.2 kW system87% offset

Full rooftop array sized to a family's actual time-of-use billing history, not a rough estimate.
SolarEdge inverter, disconnect, and utility meter installed on a Terawatt Solar project

Completed Residential Array

Net metered25-yr warranty

Finished install backed by manufacturer product warranties and our own workmanship guarantee.
Terawatt Solar installer with the branded service van, Ontario solar company crew installing rooftop panels
Why Local Matters

Why Ontario Homeowners Choose Terawatt As Their Solar Company

A lot of solar companies advertising in the GTA are sales offices in another province or country, handing your job off to whichever subcontracted crew is free that week. Terawatt Solar is headquartered at 7030 Woodbine Ave in Markham. When you call, you reach the people who will actually be on your roof, whether you're in Toronto or out toward Burlington.

That matters for more than convenience. Our racking, flashing, and weatherproofing choices account for Ontario's freeze-thaw cycles and heavy snow load on every residential install, details a company designing for a warmer climate doesn't think about until a roof leak shows up two winters later. See real examples in our case studies.

As a solar company in Ontario, we are not a call centre dispatching a subcontracted crew. Our ECRA/ESA electrical contractor licence is verifiable through the Electrical Safety Authority's contractor locator, every customer gets a free app to monitor production in real time, and every install is backed by our 8-year cost-free warranty on product replacements. We also offer in-house solar financing, and when a neighbour or friend goes solar with us on your referral, we pay you a $750 thank-you. Larger properties can also look at ground mount solar, and our Ontario solar incentives guide explains every rebate and program in plain language.

Full satellite solar panel array layout design from a real Terawatt Solar proposal, Ontario solar company system design
How We Actually Work

Real Numbers Before You Sign Anything

Every quote we send is built from your actual hydro billing history, not a satellite guess at your roof. We model both the net metering path and the Home Renovation Savings Program rebate path side by side, because for a lot of households one clearly beats the other and a generic quote never tells you which.

We handle your building permit, electrical inspection, and utility interconnection directly with your local hydro provider as part of every residential solar installation. No handoff to a second subcontractor, no separate company showing up months later to finish what another one started.

Aerial view of a Terawatt Solar rooftop installation, Mississauga, Ontario
Why Solar In The GTA Now

Ontario's Time-of-Use Rates Make Solar A Straightforward Decision

The Greater Toronto Area isn't short on sunlight, and it's definitely not short on rising electricity costs. On-peak time-of-use pricing has pushed well past 20 cents per kWh in recent years, with further increases expected, which is the real driver behind the solar adoption we're seeing across Markham, Mississauga, Brampton, and Toronto itself.

  • Ontario on-peak rates keep climbing. Your solar system's output cost locks in today.
  • We model net metering and the HRSP rebate side by side so you pick the better math, not the better sales pitch.
  • Our racking and electrical work are built for Ontario winters, not adapted from a warmer-climate design.
  • Toronto to Kitchener, we install across the full GTA and into southwestern Ontario.
  • We handle all permits, utility interconnection, and inspection paperwork in house.

Related reading: how net metering works in Ontario, is your roof a good fit for solar, and our HRSP rebate guide. We serve all GTA locations including commercial solar projects.

What Clients Say

Homeowners And Businesses Across The GTA

4.6 stars from 38 reviews on Google, every one from a real installed client. Visit our Google Business Profile to read the full, unfiltered set.

★★★★★

"Installing solar panels was a great investment in my home and reduced my electricity bill every month. I had a great customer experience with Terawatt Solar. The team tailored the panels to fit my needs and was very professional to work with for installation."

Marius & Luiza, Cambridge, ON
★★★★★

"Cosmin and his team did a great job on my install. They were able to finish the 10kW system in about 3 days. Cosmin also helped troubleshoot some issues after the fact and even came on Boxing Day to try to fix the issue."

Alvin Chung · Google review
★★★★★

"I had a 10.24 kWp SolarEdge system installed by Terawatt Solar and the whole experience was excellent. The ESA inspector was done in under 5 minutes, he told us Terawatt is one of only two companies where inspections are always that smooth because their wiring is clean and their layouts are consistent. Their pricing was better than any other quote I received."

Daniel Valadares · Google review
Aerial view of a Terawatt Solar rooftop installation across the Greater Toronto Area
Service Area

Solar Installation Across The Greater Toronto Area

From our Markham head office we install residential and commercial systems throughout the GTA, Halton Region, Waterloo Region and into southwestern Ontario. Not listed below? We serve communities across Ontario, so ask us or see all locations we serve.

Toronto Markham Mississauga Brampton Vaughan Oakville Burlington Hamilton Kitchener
Frequently Asked Questions

Solar Panel Installation Questions, Answered

Is solar power worth it in Ontario in 2026?
Yes. Ontario electricity rates increased roughly 29 to 30 percent in November 2025 and are projected to keep climbing through 2028, driven by nuclear refurbishment costs and grid infrastructure investment. A properly sized system from an Ontario solar company locks in your generation cost for 25 plus years, typically cutting your bill by 70 to 90 percent, with most GTA residential systems paying back in 9 to 13 years. High-efficiency bifacial panels used across our installs can also gain extra winter production by reflecting sunlight off snow. Run your own numbers in our solar calculator or browse real GTA case studies.
How much do solar panels cost in Ontario?
Installed residential solar panels in Ontario Canada generally run $2.60 to $3.30 per watt before incentives, so a typical 9 kW GTA home system lands around $23,000 to $30,000. A standard 7.5 kW system can run closer to $18,000 to $24,000, while a larger 10 kW system may reach $24,000 to $35,000 depending on roof complexity and panel efficiency. See our residential solar page for a size-by-size breakdown, or request a free assessment for numbers specific to your roof.
What is the warranty on a Terawatt Solar installation?
Terawatt Solar backs every install with an 8-year cost-free workmanship warranty covering labor and product replacement. The Canadian Solar panels we install also carry a 25-year manufacturer performance warranty, so your system stays productive for decades, and our 30-year panel trust claim reflects that extended performance life. Read more on our about page or see our residential solar and commercial solar install process.
What's in the solar proposal?
Every proposal starts with a satellite roof analysis and a full 12-month utility bill audit, not a generic estimate. You get your projected payback period, 25-year savings estimate, and IRR calculated from your actual energy consumption, with both the net metering path and the HRS rebate path modeled side by side so you can choose whichever delivers the better return for your specific home. Request your proposal to see both scenarios.
What is net metering and can I still get it in the GTA?
Net metering credits you for solar power sent back to the grid, applied against what you draw at other times. Toronto Hydro and most other GTA utilities still offer it to customers who skip the HRS solar rebate. For many higher-usage homes, net metering alone produces a faster payback than the rebate route, which is why we model both. Full mechanics are in our net metering guide, net metering blog explainer, and our Toronto Hydro-specific net metering page if you're inside the city.
What is the HRS Rebate and does it cover solar?
Ontario's Home Renovation Savings program offers up to $10,000 in stackable rebates, up to $5,000 toward solar and up to $5,000 toward battery storage installed alongside new solar, with no home energy assessment required for either. The catch: accepting the solar rebate currently disqualifies that system from net metering for its lifetime, so we model both scenarios before you decide. See our incentives and rebates guide for current program details.
Does battery storage make sense for a GTA home?
Battery storage is most valuable for homes wanting backup power during an outage, or wanting to shift self-generated solar into expensive evening on-peak hours instead of selling it back cheaply. The HRS battery rebate only applies when the battery is installed alongside new solar, so timing both together is usually the better financial move. See our battery storage page for how we size a battery to your actual usage pattern.
Can I finance solar in Toronto without using the HRS rebate?
Yes. The City of Toronto's Home Energy Loan Program (HELP) offers low-interest financing repaid through your property tax bill, and it can be used alongside or instead of the HRS rebate depending on which combination nets you the better outcome. We'll model this option for Toronto properties during your proposal.
Is there a federal tax credit for solar in Ontario?
Yes, but only for businesses. Canada's Clean Technology Investment Tax Credit offers a refundable 30% (or 20%, depending on labour conditions) credit against the cost of a commercial solar installation. It does not apply to residential systems. See our commercial solar page for how this stacks with other business incentives.
Do you take care of utility interconnection?
Yes. Our in-house team manages every local utility's interconnection process directly, from application to meter swap, including Alectra, Toronto Hydro, Burlington Hydro, Oakville Hydro, and others across Ontario, plus the building permit and electrical inspection. You never need to contact your utility directly. See our commercial solar page for how this works on larger projects.
Are you an ESA certified solar installer?
Every Terawatt Solar installation is completed by our own ECRA/ESA-licensed Master Electrician, never an unknown subcontracted crew. Ontario's Electrical Safety Authority requires all solar electrical work to be performed by a licensed contractor, and our licence is verifiable through the ESA Contractor Locator Tool. Meet our team on the about page.
How long does it take to pay off a solar system in the GTA?
On recent Terawatt Solar client designs, cash payback on a net-metered residential system typically falls in the 9 to 13 year range depending on roof orientation, shading, and household usage, with the system continuing to produce for well over a decade past that point. See our case studies for real project numbers, not marketing averages.
What makes Terawatt Solar different from other solar companies in Ontario?
Terawatt Solar is one of Ontario's longest-running solar installers, and every installation is done by our own ECRA/ESA-licensed Master Electrician and crew, never a subcontractor. Each proposal starts with a 12-month utility bill audit and models both the net metering path and the HRS rebate path, and we manage permitting and utility interconnection from application to meter swap. See the about page to meet the team.
Does Terawatt Solar offer solar financing in Ontario?
Yes. We offer in-house solar financing so your monthly payment can be comparable to or lower than your current hydro bill, and we can often include 0 percent interest options, so ask us for current terms. Toronto homeowners can also look at the City's HELP program. We model each financing route against the rebate and net metering paths in your proposal. See our HELP guide for details.
What areas does Terawatt Solar serve?
We install across the Greater Toronto Area including Toronto, Markham, Mississauga, Brampton, Vaughan, Oakville, Burlington, Hamilton, and Kitchener, with our main office in Markham.
Find Us

Visit Or Call Our Markham, Ontario Office

Terawatt Solar is located at 7030 Woodbine Ave, Suite 500, Markham, Ontario, L3T 6G2, in the heart of York Region, minutes from the GTA's major highways. We serve residential and commercial customers throughout Ontario, with the deepest expertise in the Greater Toronto Area, Halton Region, Waterloo Region, and surrounding communities.

Hours
Monday to Friday, 8:00 AM to 5:00 PM
Service Territory
Greater Toronto Area and all of Ontario

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Aerial solar proposal panel layout design rendering for an Ontario solar company installation

Ready To See Your Real Savings?

Get a free, no-obligation assessment from Terawatt Solar's in-house design team. We'll review your roof, your hydro bill, and both the net metering and rebate paths available to you.

Book a Solar Discovery Call
Or call us directly at (877) 648-3323