Solar + EV integration
A real annual and monthly cost baseline starts with your driving and grid rate, flat or time-of-use. This is the number to compare solar savings against.
How it works
Step 1
The same driving numbers used across the site's other EV tools apply here too, so you can reuse figures from earlier calculators.
Step 2
Check your utility bill or rate schedule to see which structure applies. Many utilities in California, and increasingly elsewhere, default new EV owners onto a time-of-use plan.
Step 3
Take this annual cost figure to the solar vs grid comparison tool to see exactly how much a solar system could save.
Knowing your real grid-only charging cost gives you an honest starting point before evaluating whether solar makes financial sense. Without this number, it's easy to either overestimate solar's benefit by comparing against an inflated grid cost, or underestimate it by not accounting for your actual driving pattern and local rate.
A flat rate charges the same price per kWh no matter when you use power, which makes budgeting simple but leaves potential savings on the table if your utility offers a time-of-use option, per EIA electricity data. Time-of-use plans typically charge significantly more during afternoon and early evening peak hours and considerably less overnight, which lines up well with typical EV charging habits since most people plug in when they get home or set a scheduled overnight start.
Most EVs and home chargers support a delayed-start feature that lets you plug in any time but only actually draw power during a scheduled window, typically overnight when off-peak rates apply. Shifting charging from 100% peak-hour to mostly off-peak can cut the effective blended rate by a meaningful margin, independent of whether solar is part of the picture at all.
Real utility bills often include tiered pricing, covered by the flat rate vs tiered rate savings comparison, that increases per-kWh cost as total usage rises, demand charges based on your highest draw in a billing period, and seasonal rate adjustments. This calculator estimates the direct energy cost of charging specifically, which is usually the dominant factor, but your actual bill increase may differ slightly from this figure depending on your utility's full rate structure.
Compare this annual cost directly against the solar vs grid cost comparison tool to quantify potential savings, or check the charging schedule optimizer if you want to shift more charging into off-peak or high-solar hours. If you charge at night, a battery matters more than panel count. The battery charge time from solar calculator in our Battery & Storage section can help you size one for overnight charging.
Questions
A driver covering 30 miles a day at a flat $0.15 per kWh rate spends around $467 a year, or about $39 a month, on home EV charging. Actual cost depends heavily on your local electricity rate and vehicle efficiency.
Shifting most charging to off-peak hours can meaningfully lower your blended rate. Charging 90% off-peak at $0.10 per kWh and only 10% during peak hours at $0.32 per kWh brings the effective blended rate down to about $0.12 per kWh, compared to $0.15 flat.
This calculator estimates the electricity cost of charging specifically, but utility bills often include tiered pricing, demand charges, or seasonal rate changes that shift your blended rate up or down depending on your total household usage. Check your utility's actual rate schedule for the most precise figure.
Yes, if your utility offers time-of-use pricing, scheduling most charging sessions during off-peak hours, usually overnight, typically saves money regardless of whether you have solar. Most EVs and chargers support a delayed-start schedule that makes this automatic once set up.