Solar and electric vehicles: sizing and charging

An electric vehicle is often the biggest single addition to a home's electricity use. It is also one of the best reasons to look at solar, because the extra kWh can come from your own roof. This guide shows how to estimate an EV's electricity use, how much solar it takes to cover it, and how to think about charging times on Ontario's rate plans.

How much electricity an EV uses

Natural Resources Canada rates EVs in kWh per 100 km on the EnerGuide label. Recent models in NRCan's Fuel Consumption Guide range from about 16 kWh/100 km for efficient small crossovers to about 27 kWh/100 km for large electric pickups. Many mid-size cars and crossovers sit around 17 to 20 kWh/100 km.

To estimate your use:

1. Find your vehicle's combined rating on its EnerGuide label or in NRCan's Fuel Consumption Guide.
2. Multiply by your yearly kilometres, divided by 100.
3. Add a margin for winter. Cold weather, cabin heating and battery warming raise consumption noticeably in a Canadian winter, and real-world use is usually higher than the lab rating.

These are rating-based figures before winter and charging losses. For a household that uses 8,000 kWh a year, an EV driven 15,000 km can add a third or more to the total.

Sizing solar for an EV

In our model, a Toronto roof produces about 1,086 kWh per year for every kW of panels. So covering 2,700 kWh of EV charging takes roughly 2.5 kW of extra panels, about six panels of 400 to 450 watts. Sunnier Prairie cities need a bit less; the coast and Newfoundland need more.

At typical 2026 Ontario installed prices of $2.42 to $3.05 per watt, that extra 2.5 kW adds very roughly $6,000 to $7,600 to a system before any incentives. Adding panels during the original installation is usually cheaper per watt than adding them later.

Things to weigh:

• Roof space. Your roof may not fit enough panels for both the house and the car. Covering part of the EV's use still helps.
• Net metering limits. Utilities generally expect a net-metered system to be sized to your expected use. A planned EV is a good reason to size up, but ask your installer how your utility treats it.
• Planned, not yet bought. If the EV is a few years away, you can size the system for it now if your utility allows, or choose an inverter with room to add panels later.

Our system size tool lets you add expected EV use.

Charging timing: solar vs Ultra-Low Overnight

Ontario's Ultra-Low Overnight (ULO) plan was designed with EVs in mind. From November 1, 2026, the Regulated Price Plan rates are:

These prices are before delivery, regulatory charges and HST.

Solar produces most during the day, but most cars are charged overnight. That looks like a mismatch. In practice:

• With net metering, your daytime surplus goes to the grid and earns credits. You then charge overnight from the grid. Your utility handles how credits apply to your bill, and it is worth asking how it treats credits across ULO periods. Charging overnight at 3.7¢ is very cheap regardless.
• The expensive window is 4 to 9 pm on weekdays at 37.7¢. On ULO, avoid charging then. Solar output fades in those hours, especially in winter, so solar doesn't protect you from that price.
• Without net metering, such as a system that takes Ontario's HRSP solar rebate, exported power isn't credited. If your car is home during the day, charging it from the panels in the middle of the day gets the most value from your solar. Many chargers and apps can schedule charging around solar output.
• ULO isn't for everyone. If your household runs a lot during weekday evenings, the 37.7¢ on-peak price can outweigh the overnight savings. Use our rate plan comparison and read Time-of-Use vs Ultra-Low Overnight.

Home charging basics

• Level 1 uses a regular 120-volt outlet. It adds only a few kilometres of range per hour, which can be enough for short daily commutes.
• Level 2 uses a 240-volt circuit, like a dryer. A typical 7 kW charger adds roughly 35 to 45 km of range per hour for a mid-size EV. Most EV owners install one.
• A Level 2 charger needs a licensed electrician, a permit and an electrical inspection. Older homes with 100-amp service may need a load calculation, a load management device or a service upgrade, especially if you are also adding a heat pump.
• Plan solar and EV wiring together if you can. One electrician visit for both is simpler and often cheaper.

Next step

See how much an EV would change your solar sizing and savings: check your roof.

Common questions

How much electricity does an electric car use per year in Canada?

A typical EV driven 15,000 km uses roughly 2,400 to 3,750 kWh a year based on its rating, more in cold weather. Check your car's kWh per 100 km on its EnerGuide label.

How many solar panels do I need to charge an EV?

In Toronto, about 2.5 kW of extra panels, roughly six panels, covers an EV driven about 15,000 km a year. Sunnier cities need a bit less.

Is it better to charge my EV during the day with solar or overnight on ULO?

With net metering, overnight charging at 3.7¢ on ULO is usually cheapest while your daytime surplus earns credits. Without net metering, daytime charging from the panels gets the most from your solar.

Do I need a Level 2 charger?

Most EV owners install one because it adds roughly 35 to 45 km of range per hour. It needs a licensed electrician and may require an electrical service check.

Sources

• Natural Resources Canada: EnerGuide label for battery-electric vehicles
• Electric Autonomy Canada: NRCan's Fuel Consumption Guide highlights the operating cost advantage of EVs (2026)
• Ontario Energy Board: electricity price changes effective November 1, 2026