Gas vs. EV: What Does 100 Miles Actually Cost?

Assume an EV uses approximately 30 kWh to travel 100 miles. Actual efficiency varies by vehicle, weather, speed, temperature, and driving habits, but it gives us a useful baseline.

AAA currently reports average public EV charging at approximately 42¢ per kWh nationwide.

At that rate:

Now move that same vehicle to your driveway.

The U.S. average residential electricity price was approximately 18.34¢ per kWh in June 2026.

At that rate:

Now consider a gasoline vehicle getting 25 MPG. At the current national average of approximately $4.48 per gallon, driving 100 miles requires four gallons:

So, using these assumptions:

And in California, where regular gasoline is currently averaging about $6.17 per gallon, the gasoline cost for that same 100-mile drive climbs to about $24.68.

These are simplified examples. Your actual costs will depend on your vehicle, local fuel and electricity prices, charging efficiency, and driving habits.

But they demonstrate something important: The real financial advantage of an EV may have less to do with avoiding the gas station and more to do with being able to charge at home.

Solar Can Change the Math Again

Home charging is already potentially less expensive than relying heavily on public chargers. But if you produce electricity at home, you have another option.

Your EV can become another place to use your solar production.

Imagine your solar array is producing more electricity at noon than your house currently needs.

Depending on your system and utility agreement, that extra energy could be exported to the grid, stored in a battery, or used to charge your EV.

Which option provides the most value depends largely on your utility.

Should You Send Solar to the Grid or Put It in Your Car?

This is where your utility plan matters.

When your solar panels produce more electricity than your home is using, that extra energy can be sent back to the grid. Depending on your utility, you may receive a credit for that electricity. The important part is that the credit may be lower than the rate you pay when you need electricity from the grid.

For example, say your utility gives you 8¢ per kWh for electricity sent to the grid, but charges you 18¢ per kWh for electricity you use from the grid.

If you send 10 kWh of extra solar to the grid, you receive:

But if you use that 10 kWh of solar at home instead, you could avoid buying 10 kWh from the grid at 18¢:

In this example, that same 10 kWh is worth $1 more when used at home than when sent back to the grid.

This is where an EV can come into the picture. If your vehicle is home while your solar system is producing excess power, you may be able to schedule charging during those hours. Instead of selling that electricity to the grid for a lower rate, you're using it to charge your vehicle and reducing the amount of electricity you need to purchase later.

This is called solar self-consumption. It simply means using the electricity your panels produce yourself, rather than sending it back to the grid.

The goal isn't necessarily to send as much solar back to the grid as possible. It's to understand where each kWh can provide the most value.

Timing Your EV Charging Can Save Money

Solar isn't the only way to reduce charging costs.

Sometimes the biggest opportunity is simply changing when you charge.

Some utilities offer time-of-use rates where the price of electricity changes throughout the day. Electricity may be more expensive during periods of heavy demand and considerably cheaper overnight or during other off-peak periods.

That means plugging your vehicle in at 6 p.m. doesn't necessarily mean it needs to start charging at 6 p.m.

Many EVs and chargers can be scheduled to wait.

If your electricity is cheaper at midnight, your car can sit plugged in for several hours and automatically begin charging when rates fall.

Your EV doesn't care whether the electricity arrives at 6 p.m. or 2 a.m.

That flexibility is one of the biggest differences between buying electricity and buying gasoline.

You can't tell the gas station to fill your tank automatically when gasoline gets cheaper overnight.

With electricity, you may actually have that option.

This Is Where Energy Arbitrage Comes In

Combine variable electricity prices with solar and energy storage, and things get even more interesting.

The concept is known as energy arbitrage, but the basic idea is pretty simple:

Depending on your utility, solar system, battery, and rate structure, that could mean:

The most cost-effective way to charge and use energy will depend on your utility rates and your solar production. If your utility offers inexpensive overnight electricity, charging your EV from the grid at night may make the most sense. If you produce plenty of solar during the day but receive a relatively low credit for sending excess power back to the grid, using more of that solar yourself could provide greater value. And if your utility charges higher rates during peak hours, battery storage could help reduce how much electricity you need to buy during those more expensive periods.

Does a Home Battery Make EV Charging Cheaper?

A home battery doesn't automatically make EV charging less expensive. If your utility offers very low overnight rates, for example, it may be cheaper to simply schedule your EV to charge from the grid during those hours.

Where a battery can provide value is by giving you more flexibility with the energy your home already produces and uses. Excess solar generated during the day can be stored instead of immediately sent back to the grid, then used later when solar production drops or grid electricity costs more.

Your EV can still be scheduled to charge when electricity is most affordable, whether that's from available solar during the day or lower-cost grid power overnight.

Want to Know What Makes Sense for You?

Your utility plan and driving habits can tell you a lot about the most cost-effective way to charge your EV. Start by looking at three things:

For example, consider someone with a 15-mile commute each way, or about 30 miles of driving per workday. Over a typical five-day workweek, that's roughly 600 miles per month just getting to and from work.

An EV using 30 kWh per 100 miles would need about 180 kWh of electricity per month for that commute, before accounting for charging losses.

At the national residential electricity rate of 18.34¢ per kWh, that comes to about $33 per month charging at home. At a hypothetical 10¢ off-peak rate, it drops to about $18. Using an average public charging price of 42¢ per kWh, the same commute would cost about $76.

Now compare that with a gas-powered vehicle averaging 25 MPG. Driving the same 600 miles would require about 24 gallons of gas. At the current national average of $4.48 per gallon, that's roughly $108 per month. At California's current average of about $6.17 per gallon, it climbs to about $148.

Same commute. How and where you get your energy can make a big difference in what you pay each month.

More Control Over What You Pay to Drive

There isn't one way to charge an EV that will make sense for everyone. Your electricity rates, access to home charging, solar production, and driving habits all affect what you'll actually pay.

Solar doesn't make EV charging free, and a battery doesn't automatically make it cheaper. But knowing when your electricity costs the least, and when your solar has the most value, can help you make smarter decisions about how you charge.