EV’s and Residential Solar

Could you charge your electric vehicle (EV) at home and have a $16 monthly electric bill?

As EV’s and residential solar become more popular, we’re fielding questions about combining the two. Yes, charging your EV with home solar is a great idea, as long as you do some math up front and use available solar incentives to reduce initial costs.

Charging with home solar will:

  • Further reduce your car’s carbon footprint
  • Reduce the current cost to charge the vehicle by about 57%
  • Allow you to avoid utility rate hikes in the future

For the sake of clarity and brevity, we’re referring to home solar systems, but these same methods will work just as well for commercial EV’s.

Solar charging makes sense for the planet

The average American drives 13,500 miles per year. If their car gets 32mpg, this requires 420 gallons of gas and generates over 8,100 pounds of CO2.

Charging an equivalent EV from the electrical grid for the same distances uses 3,645 kilowatt hours (kWh) of electricity and produces 2,526 pounds of CO2. But charging it with solar only accounts for 321 pounds. That’s 87.3% less than grid power and 96% less than a gas-powered car.

Even better, solar panels eventually pay off the “carbon debt” from their manufacture and become carbon neutral.

Solar charging makes financial sense today

Using a public charger costs a minimum of well over 20 cents per kWh and is always more expensive than charging at home from the grid. In the Rockford area, grid power costs 14 cents/kWh.

Meanwhile, once all costs are considered, residential solar works out to 6 cents/kWh, or 57% less.

Let’s see how that looks with a specific model, the Tesla Model 3 RWD:

Full Charge | Range       | Total Grid cost | Grid cost per mile | Total Solar cost  | Solar cost per mile

70 kWh       272 miles        $9.80                         3.6¢                     $4.20           1.5¢

Clearly, using solar to charge your EV dramatically reduces the total cost of ownership.

Solar charging makes financial sense in the long term

Solar panels last 25 years or more. Over that time, electric rates will increase about 3% per year (rising to around 25 cents) while your solar generation cost will remain the same. Over that time, you’ll own and charge multiple EV’s without suffering the rate hikes that are inflating costs for everyone else.

The right incentives and equipment will keep initial costs low

Equipping your home for solar EV charging requires only some simple calculations, some additional panels, and a Level 2 charger.

The calculation process goes like this:

  • Determine how far you will usually drive and how much power you need to charge your vehicle for those distances.
  • A single properly sited panel produces 2 kWh per day.
  • Divide the power needed by 2, and you’ll know how many additional solar panels you’ll need to completely offset charging your EV.
  • For example, the Tesla we mentioned needs 10 kWh for a round trip commute of 40 miles. That requires five solar panels.

Would that be an expensive addition? One reason the cost of home solar power is so low is that financial incentives can reduce the upfront cost of solar installation by 70%. Working with the right solar installation partner, such as Thayer Energy Solutions, can ensure you get every dollar that’s available.

What about the $16 solution?

Remember the $16 monthly electric bill we mentioned at the beginning of this article? Where does that come in?

If you’ve installed enough solar capacity to power your home and charge your EV, there will no longer be supply, distribution, or transmission charges on your bill. That only leaves ComEd’s monthly customer charge, which is currently $13 to $16.

With the right design—and help from the right solar installation partner—you can save with solar, and know you’re skipping rate hikes for decades to come.

Ready for a partner?

Not sure where to start with solar and/or EV charging? Choose Thayer Energy Solutions. We have decades of experience with energy-saving technology, know how to navigate the jungle of incentives, and are right here in your region. Get in touch and let’s see what we can do together!