Rooftop to Blacktop ™

April 27, 2017

By Laurel Hamilton — Solar PV systems and electric cars go together like PB&J. Pair the two and you can both power that hot tub you’ve been feeling guilty about AND your daily trips around town completely with clean energy from the sun!

Installing solar panels on your roof to power your electric vehicle (EV) is not only a great investment, it’s a step toward a healthier future. As Oregon’s city populations swell, reducing ozone-causing emissions will be important for maintaining our clean air. By driving a solar powered EV, you can eliminate emissions associated not only with your tailpipe but also with your utility’s electricity production. EVs have 99% less CO2 (carbon dioxide) and VOCs (volatile organic compounds), 70% less NOx (nitrogen oxides) and 32% less greenhouse gases (GHG) than gas powered vehicles. You could safely say you were doing your part to contribute toward the state’s many climate change and air quality goals!

Since EVs don’t run on gasoline, the EPA rates them based on how many kilowatt-hours (kWh) it takes to drive 100 miles, which they convert to a “miles-per-gallon equivalent” (MPGe). You can compare the MPGe ratings for all EVs on the market at Once you know the rating for your chosen EV, you can easily calculate how much extra electricity you’ll need to charge your car.

Here’s an example: The 2017 Nissan Leaf, an all-electric vehicle, has an MPGe rating of 30 kWh/100 miles. If you average 25 miles per day, you’re using approximately 7.5 kWh of electricity – or just over 2,700 kWh of electricity annually. This is the “extra” amount of electricity you may want to have your solar installer design into your solar system to ensure you’re driving with the power of the sun!

Now let’s talk $$$. Is it really more affordable to power an EV with solar compared to the grid? How does this stack up against a traditional gas guzzler? Going back to our estimate of an average 25 miles per day…

Gas Car with 25mpg ($2.70/gallon gas) $2.70/day, $985/year
EV with Pacific Power grid energy (11¢/kWh) $0.82/day, $301/year
EV with solar (Average solar cost of 3.5¢/kWh for 25 yr period) $0.26/day, $96/year


It turns out if you’re looking for an economical car, you should be considering an EV! Factor in a solar system to fuel the car and it becomes an even better investment over the long-term. Surprising? Yes, at first glance, the sticker price may seem more expensive but if you conduct a full “cost of ownership” analysis, the gap quickly narrows. An electric car is a lot less hassle to maintain – no oil or filter changes, no tune-ups, and no replacing timing belts. Even the brakes wear out less frequently since the car uses regenerative braking to recharge the batteries.

Both the electric car and the solar system have a payback time, after which the energy generated to get you from point A to point B or to brew your coffee in the morning is completely free! Bills for grid power never end, like renting a house vs. owning. Gas-sucking cars will never stop requiring that you pay at the pump – with gas price increases certain.

Worried about your EV’s driving range? It’s a valid concern! Luckily Oregon has the highest number of fast charging stations in the nation – making it easy to fully charge in as little as 30 minutes. Today’s EVs have built-in navigation to guide you to the nearest public charger. You can also check charging locations by downloading the PlugShare app. Often these stations are conveniently located at eateries where you can charge up, stretch your legs, and even grab a bite to recharge yourself for your journey.

Combining the $7,500 federal tax credit for all-electric vehicles with Oregon’s generous state solar tax and cash incentives of up to 70% of the retail price for a solar system and you would be crazy not to opt for electric! Solar-powered transportation is not just a concept for the future, it really is an affordable reality for today’s everyday commute.


(Photo credit: Left- Pine Mountain Sport, Right- Elemental Energy)