Driving on sunshine: the EV/PV connection

Photo courtesy of ReVision Energy

Photo courtesy of ReVision Energy

By Barry Woods

I have been driving a Chevy since April 2017. While not a surprising statement in itself, you might be surprised to find it uses no gas and runs on renewable electricity stored in a 60-kWh battery that straddles the frame. When passengers exit my car after their first time driving electric, they always smile. Always. My Chevy Bolt gets over 230 miles from a single charge. I plug it in at home, and it charges completely overnight. My hands never smell like gas, and my money doesn’t go to the Middle East—it goes to US-based industries, growing jobs. I save more than $50 a month on fuel compared to what I used to spend, and that’s after I pay my electricity bill. This means I have more money to spend locally, growing jobs. When I sit in traffic, I don’t idle and I don’t waste energy sitting there. When I go downhill, I often coast and add more range to the battery through regenerative braking. I remember one trip when I arrived at my destination with more range than I had when I left my house. These are but a few reasons why you might want to seriously consider driving electric, too.

There’s a new fuel in town

Our transportation system has been 99% reliant upon fossil fuel for more than 100 years. Entire generations of Americans used gas to enjoy the freedom of the road. But this “freedom” comes at a high price. Combustion engines contribute nearly a third of the greenhouse gas emissions (GHG) that cause global warming. And we have spent untold billions in military-related expenses fighting to protect our energy interests abroad and billions more for oil and gas exploration. Electric vehicles have the potential to transform our energy future by plugging them into the electric grid, thus reducing our reliance on oil and the economic, social and environmental repercussions that its usage has caused.

Electricity can be generated domestically in many ways, including through renewable energy sources such as wind, hydro and solar. Most states, including Maine, have energy policies in place to promote the adoption of increasing amounts of renewable electricity generation. So, driving electric means the car becomes even cleaner over time as our grid’s generation sources become cleaner. Cleaner electricity means cleaner transportation, an elegantly simple formula.

With electricity, you have a choice as to how to fuel your car. Many EV owners simply plug their car into their home and add it to their electric bill. In the US, driving on electricity is less polluting than using gas. And according to the Union of Concerned Scientists’ State of Charge report, even if you live in a state where your electricity comes solely from coal (which is increasingly rare in the United States as coal power plants get mothballed), because the electric drive uses energy more efficiently, driving on it still generates only a third to half the amount of greenhouse gases that driving a gas-powered vehicle generates.

In most regions of the country, standard electricity is generated by a collection of fossil fuel and renewable energy sources, so the actual amount of electricity-based emissions varies. In Maine, we are fortunate to have the cleanest electric grid in New England, with substantial amounts of hydro and increasing amounts of wind and solar.

For those wanting to step it up a notch, one way to ensure that your electricity comes from 100% clean sources is to elect the green power option provided by your local utility, including Central Maine Power and Emera Maine. For a nominal additional rate increase, you can elect to use clean energy exclusively for your home (which also provides some incentive to the utilities to keep growing renewables as part of their portfolios). Using grid-based energy is a great solution to unleashing the benefits of the electric drive. But, as we shall see, there is an even more cost effective option.

The solar gallon

Photo courtesy of ReVision Energy

Photo courtesy of ReVision Energy

EV drivers have another choice for their electricity—going solar. Solar offers many long-term advantages for the average consumer, not the least of which is significant cost savings. The US Department of Energy uses the term “eGallon” to describe the equivalent cost of driving an electric vehicle when compared to driving a gas-powered vehicle.

In 2017, the eGallon was calculated at half the price of gas, just $1.16, compared to an average US gas price of $2.32 per gallon. However, if your electricity comes from your own solar panels, the solar gallon costs an equivalent of 71 cents. This price is the levelized cost over the twenty-five-year warranty of a typical residential solar array (6 kW), meaning your transportation fuel cost stays fixed! The reality is that the array will probably have an even longer useful life than 25 years, so we are being conservative.

In addition, the cost savings on gas usually accelerates the payback on the solar investment by 30%. Stated alternatively, gas is so much more expensive than electricity as a fuel source that weaning yourself off it has an immediate economic impact on your family’s energy budget, which can be leveraged into an investment in solar that further adds to your savings.

The average Maine household, traveling 10,000 miles per year in their car, would need to purchase roughly eight solar panels to produce the energy needed to fuel this distance (3000 kWh). This translates into a modest array size of 2.6 kW, which would cost approximately $6,500 (cash price) after using the available federal tax credit. If we look at the 25-year warranty life for the panels (even though most go much longer), this investment would yield 25 years of energy production for their car (or 250,000 miles).

At the current price of gas, $2.32, that same 250,000 miles for a 30-mpg efficient vehicle would take 8,333 gallons of gas and cost the consumer $19,333. And that assumes the price of gas will remain stable for 25 years—not a likely scenario. With the solar option costing approximately $6500 for 25 years of driving and the gas option costing $19,333, it’s easy to see how quickly the savings add up.

By choosing to invest in electric vehicles and solar, consumers can provide themselves dramatic fuel cost savings and lend their voices to a growing chorus of Americans who see clean electricity as the path to energy independence. Will you ever look at your car the same way again?



In 2017, we are already seeing 37% growth in EV sales compared to the first 6 months of 2016. All major automakers have expressed interest in funding longterm research and development of their versions of plugin electric vehicles, with several going so far as to say that electric is the future of the company (GM, Nissan, Ford, BMW, Volvo). And Tesla has made electrification its mission from the beginning.

2017 was also an industry milestone, as it marked the release of the next generation of affordable all-battery electric vehicles (BEVs). These nextgen BEVs can achieve ranges of more than 300 miles on a single charge. And most offer models priced in the $30-$35,000 range. The future is bright as more manufacturers deepen their bench of product offerings to include SUVs and minivans, giving consumers more choices to fit their transportation needs.



This article was reprinted from the fall 2017 issue of Green & Healthy Maine Homes. Subscribe today!