A Beginner's Guide to Tesla Solar: How It Actually Works
Tesla Solar has a lot of vocabulary around it. Solar roof. Solar panels. Powerwall. Inverter. Net metering. Time-of-use. It can feel overwhelming before you even get to the part where someone tells you what it costs. This is the plain-English explainer. Start here.
The Two Products: Solar Panels vs. Solar Roof
Tesla makes two solar products. They're often confused. They're very different.
Tesla Solar Panels: Standard photovoltaic panels that go on top of your existing roof. They look like regular solar panels because they are regular solar panels. Black rectangular panels, mounted on rails above the shingles. This is what most people buy. It's more affordable, more widely available, & easier to install.
Tesla Solar Roof: The shingles are the solar panels. The whole roof is replaced with Tesla's glass tiles that generate power. This is for roofs that need replacing anyway, or for owners who strongly prefer the integrated aesthetic. It costs significantly more & takes longer to install.
Unless you have a specific reason for the Solar Roof, Tesla Solar Panels are what you're looking at.
How Solar Panels Actually Work
The panels sit on your roof & convert sunlight into DC (direct current) electricity. That DC power then travels to an inverter, which converts it to AC (alternating current), the kind your home actually uses.
From there, the electricity flows into your home's electrical panel & powers whatever is running at that moment: lights, fridge, TV, EV charger, everything.
If you're generating more than you're using, the surplus goes somewhere. Where it goes depends on whether you have a Powerwall or not:
No Powerwall: Surplus goes back to the grid. In Ontario & BC (with 1:1 net metering), you get credited at the same rate you buy electricity, essentially the meter runs backward.
With a Powerwall: Surplus goes into the battery first. You fill the battery before anything goes to the grid. Then, when the sun goes down, you draw from the battery instead of the grid.
If you're using more than you're generating (cloudy day, night, big appliances running), the shortfall comes from the grid. Your home always has power. The system blends solar, battery, & grid seamlessly.
What the Powerwall Adds
The Powerwall 3 is a wall-mounted battery, 13.5 kWh of storage, about the size of a large suitcase. It connects between the solar system & your home.
Here's what it changes:
It shifts when you use your solar energy. Without a Powerwall, your solar power is "use it or lose it." You either use it right now or export it. With a Powerwall, you store it & use it after dark, when it's more valuable (especially on Ontario's ULO rate plan where peak prices are high).
It provides backup power. If the grid goes down, a Powerwall keeps your house running. Without a Powerwall, even if you have solar panels, a grid outage means your panels shut off (required by law, to prevent backfeed onto lines where workers might be). With a Powerwall, the system isolates your home & keeps running on solar + battery independently.
The Powerwall 3 specifically has a built-in solar inverter, meaning you don't need a separate inverter for the panels. It's one box that does both jobs, which simplifies installation & reduces cost.
Net Metering: Getting Credit for What You Export
Net metering is the arrangement with your utility where exported solar power earns you a credit against what you use from the grid.
In Ontario, it's true 1:1 net metering. You get credited at the full retail rate for whatever you export. If you export 100 kWh in a billing period & use 150 kWh from the grid, you pay for the net difference (50 kWh).
In Manitoba & Saskatchewan, export rates are lower than retail, so self-consuming your solar (via a Powerwall) is worth more than exporting.
Important Ontario caveat: Under the HRSP rebate program, if you claim the $5,000 solar rebate, your system cannot participate in net metering. You can still claim the $5,000 battery rebate without this restriction. A good installer will help you model which configuration saves more over time.
The Powerwall App: How You Monitor It
Once a Tesla solar + Powerwall system is installed, the Tesla app becomes your energy dashboard.
You can see, in real time:
How much solar your panels are producing (kW)
How much your home is consuming (kW)
Whether the Powerwall is charging or discharging
Whether you're importing or exporting from the grid
Your Powerwall's current state of charge (%)
The app also shows historical graphs, daily, weekly, monthly. Most new solar owners spend a lot of time watching this at first. It's oddly satisfying to watch the house run on solar & the grid import line stay at zero.
The Installation Process
Once you've got a quote & decided to go ahead:
Pre-approval for rebates (in Ontario, HRSP pre-approval is required before installation, don't skip this)
Tesla or a certified installer does a site assessment (roof orientation, shading analysis, panel count)
Permits are pulled with the municipality
Installation day, typically 1-2 days for panels, 1 day for Powerwall
Utility inspection & grid connection
Commissioning & Tesla app setup
Timeline from approval to live: typically 6-12 weeks in Ontario.
What Makes Tesla Solar Different
A few things distinguish Tesla's approach from other installers:
Direct pricing. Tesla sells solar without a dealer or reseller markup. Quotes are generated online in about 10 minutes with no sales call required.
Integrated ecosystem. If you have a Tesla car, the app already handles the vehicle. Adding Powerwall & solar brings everything, car, battery, home energy, into one dashboard.
The Powerwall 3's built-in inverter. This is a real practical advantage. Fewer boxes, simpler installation, one point of failure instead of two.
The Short Version
Solar panels convert sunlight → electricity. The Powerwall stores it for later. The inverter makes it usable. Net metering credits you for what you export. The app shows you all of it in real time.
Add a Tesla to that system & you're charging your car from the sun for essentially free once the system pays back. That's the long game, & for a lot of homeowners, it's starting to make real financial sense.
