Why panel capacity is the whole question
A Level 2 charger is one of the largest continuous loads in a house. Your service panel has a finite capacity, and an electrician has to demonstrate on paper that adding this circuit keeps the total within it.
If it does, the job is a breaker, a run of conduit and a mount. If it does not, you are looking at either a service upgrade or a load management device, and those are different orders of cost.
Load management is the underrated answer. Rather than adding capacity, it prevents the charger and another large appliance from drawing at full tilt simultaneously.
What solar actually changes
Solar does not feed your car directly in any meaningful sense. Electricity from the array goes onto your house wiring; if the car is charging at that moment it uses it, and if it is not, the electricity goes to the house or the grid.
So the interaction is behavioural, not technical: charging during daylight uses your own production, charging overnight uses grid electricity.
Under a time-of-use tariff, this matters a lot. Under net metering with a favourable export rate, it matters much less, because exporting and importing net out.
A battery changes the picture again, and not always favourably — cycling your home battery into a car is usually a worse use of it than covering household evening load.
The one sizing mistake people make
Buying the fastest charger available and then discovering the panel will not support it.
Most household charging happens overnight across eight to twelve idle hours. A lower-amperage charger that fits your existing panel will usually refill a daily commute comfortably, and costs nothing extra in electrical work.
Size the charger to your driving and your panel, not to the spec sheet.
How the work runs
- Load calculationAn electrician calculates whether your service can take the new circuit. This is the step that determines everything downstream.
- Choose the locationWhere the car parks, and how far that is from the panel. Conduit distance is real money.
- Choose the charger and amperageMatched to your panel capacity and your actual daily mileage, not to the maximum available.
- Resolve capacity if neededLoad management device, circuit sharing, or a service upgrade — in roughly that order of cost.
- PermitMost jurisdictions require an electrical permit for a new dedicated 240V circuit.
- Install and inspectCircuit, conduit, mount and commissioning, followed by inspection.
What moves the price
We do not publish a national average and present it as your price. These are the variables that separate two quotes for the same job — run your own numbers with the cost guides and calculators, and check what incentives you actually qualify for.
| Factor | Why it moves the number |
|---|---|
| Panel headroom | The single largest variable. Enough spare capacity makes this a straightforward job; no headroom changes the project entirely. |
| Distance from panel to parking | Conduit, wire and labour scale with the run. A detached garage is a different project from an attached one. |
| Trenching | Any run that crosses open ground adds significant cost. |
| Load management vs service upgrade | A managed circuit is usually far cheaper than increasing your service. |
| Charger choice | The cheapest line item in most quotes, and the one people focus on most. |
What to ask before you commit
Take this list to the conversation. A professional who answers these directly is telling you a lot; one who deflects is telling you more.
- What does the load calculation say, and can I see it?
- What amperage will this circuit actually support?
- Is a load management device an option instead of a service upgrade?
- What is the conduit run, and is any of it trenched?
- If I add solar or a battery later, does this installation need redoing?
Common questions
Do I need solar to install an EV charger?
No. They are independent. A charger is an electrical circuit; solar is a generation system. Having both lets you charge on your own production during daylight hours, which is a behavioural benefit rather than a technical one.
Will my solar panels charge my car?
Only if the car is plugged in and charging while the panels are producing. Electricity is not stored on its way to the car — charge at night and you are using grid electricity regardless of how much your array made that day.
Do I need a panel upgrade?
Only if the load calculation says your service cannot take the circuit. Load management devices often avoid an upgrade by sharing existing capacity rather than adding more.
How fast a charger do I need?
For most people, less than they think. Overnight charging across eight to twelve hours refills a typical daily commute even at modest amperage.