Adding an EV to your home? Your solar system needs to be bigger than you think. Here's exactly how to size solar + EV charging so you drive on sunshine — not grid power.
Electric vehicles are the fastest-growing reason homeowners are going solar — or upgrading an existing solar system. Charging an EV at home adds 3,000–5,000+ kWh to your annual electricity usage.
If your solar system wasn't sized for that, you're still paying the utility for most of your fuel.
Here's how to get it right — whether you're buying solar and an EV together, or adding an EV to an existing solar home.
| Vehicle | Est. Annual kWh (12k miles/yr) | Equivalent Monthly kWh Added |
|---|---|---|
| Tesla Model 3 (RWD) | ~3,500 kWh | ~292 kWh/mo |
| Tesla Model Y (LR) | ~4,200 kWh | ~350 kWh/mo |
| Ford F-150 Lightning | ~5,500 kWh | ~458 kWh/mo |
| Chevy Equinox EV | ~3,200 kWh | ~267 kWh/mo |
| Rivian R1T | ~5,800 kWh | ~483 kWh/mo |
For context: the average American home uses about 10,500 kWh per year. Adding a mid-size EV increases your total consumption by 30–55%. An electric truck can increase it by 50%+.
If your current solar system was sized for your home without an EV, it's now significantly undersized.
Add your home's current annual kWh (from your utility bills) to your EV's estimated annual consumption.
Example: 10,500 kWh home + 4,200 kWh Tesla Model Y = 14,700 kWh total annual usage
Your solar system's output depends on how many peak sun hours your location gets daily:
Oregon
4.0–4.5 hrs
Texas
5.0–6.0 hrs
Arizona
6.0–7.5 hrs
More sun = fewer panels needed for the same output
Divide your annual kWh need by your location's annual solar production per watt:
Annual kWh ÷ (peak sun hours × 365 × 0.80 efficiency) = system
size in kW
Example: 14,700 kWh ÷ (5.0 × 365 × 0.80) = ~10.1 kW system needed for a Texas home with a Model Y
Solar Care Connect does this math for every homeowner we work with, using your actual utility bills and your specific EV model. It takes about 10 minutes and it's free.
Paired with solar and a battery, you can time charging to happen during peak solar production hours — essentially charging your car on free sunshine rather than grid power.
Some EV chargers (like the Tesla Wall Connector and Emporia Smart Charger) can integrate with home energy management systems to:
This is the most efficient setup for a solar + EV home.
Pull 12 months of production data from your solar monitoring app:
If you're sending excess power to the grid...
You may have room to absorb EV charging without adding panels
If you're barely offsetting your home load...
You'll need to expand the system
Most solar systems can be expanded — but it depends on your inverter's capacity:
Have a maximum input. If yours is maxed out, you may need a second inverter or an upgrade.
Easiest to expand — each panel has its own inverter, so you can add panels individually.
If you're adding panels for EV charging anyway, it's worth pricing battery storage at the same time:
Solar Care Connect specializes in helping homeowners who drive electric — or who plan to — get properly sized solar systems from day one. We compare quotes from 10+ installers across Oregon, Texas, Arizona, Michigan, New Mexico, New York, New Jersey, and Washington.
Don't make this mistake:
Don't get a system sized for your home today and discover in 6 months it can't handle your new truck. Get it right the first time.
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