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Calculator · Updated August 2026
EV charging on solar calculator
An EV adds 25–35% to a typical household's electricity use. Here is what that costs.
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The calculator
What does charging an EV add, and what would cover it?
Home charging at your all-in rate. Public DC fast charging typically costs two to three times this. Charging losses of roughly 10% are included.
This is an estimate, not a savings guarantee.
It uses published utility rates, NREL regional sun data and a standard system derate. It does not know your roof orientation, your shading, your usage pattern or what your utility will charge next year. No solar company can honestly guarantee savings, and any that does is describing a model rather than making a promise.
An EV is a second house on your meter
Twelve thousand miles at typical efficiency is roughly 3,400 kilowatt-hours a year including charging losses. For many households that is a 25–35% increase in electricity consumption, and it arrives all at once when the car does.
That matters for solar sizing more than almost anything else. A system sized to last year's usage will be undersized the month you buy an electric car, and adding panels later costs more per watt than including them at the start.
When you charge changes what it costs
On a flat rate it makes no difference. On time-of-use it makes a large one, and an increasing number of utilities are moving residential customers onto time-of-use. Charging overnight on an off-peak rate can cost half what charging at 6pm costs.
With solar and a low export credit, daytime charging is the best case — you are consuming your own production at the retail rate instead of exporting it at avoided cost. In California under net billing, that difference is roughly four to one.
Solar sizing for an EV
The figure above shows the extra array needed to cover your driving. Two practical notes: your electrical service has to accept both the charger and the solar interconnection, and older 100-amp panels frequently need upgrading for either. That cost belongs in the comparison and often appears late in proposals.
The gasoline comparison, honestly
The figure above uses $3.40 a gallon and 28 miles per gallon. Both are assumptions and both move. Fuel prices are volatile in a way electricity rates are not, and electricity rates rise steadily in a way fuel prices do not. Neither comparison is stable, which is why we show the arithmetic rather than a headline saving.
What is stable: an EV charged at home on your own solar production is the cheapest mile available to a homeowner, and it gets cheaper relative to the grid every time your utility files an increase.
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Who you would be working with
SolarAmerica
We design your system and manage the project; installation is performed by vetted licensed partners in your area. SolarAmerica is not itself the installing contractor.
Questions
The things people actually ask
How much does it cost to charge an EV at home?
Divide annual miles by efficiency in miles per kilowatt-hour, add about 10% for charging losses, and multiply by your all-in rate. At 12,000 miles and a 20¢ rate that is roughly $680 a year.
How much solar do I need to cover an EV?
Usually 2–3 kW of additional array for typical annual mileage. The figure above calculates it for your state's sun resource.
Should I charge during the day or at night?
With solar and a low export credit, daytime is better — you consume your own production at retail value instead of exporting it at avoided cost. On time-of-use without solar, overnight is usually cheaper.
Will my electrical panel handle it?
Older 100-amp services often need upgrading to support both a charger and a solar interconnection. Get that assessed before budgeting.
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