In September 2011, my wife Diane and I installed a new, 1.8 kilowatt hour photovoltaic array on our garage roof. Two days later, we purchased a 2012 Chevy Volt.

Since then, almost every time we park it somewhere, someone inevitably stops us and ask us to explain what our car's license plate ("SUN POWR") and plate holder, "Driving on Sunshine," means. We are always happy to explain.

Now that we have just recently completed our first year behind the wheel of this remarkable new technology, we are able to provide you with some real numbers.

Miles driven: 3,200. Electricity used: 800Kwhs. Electricity produced by PV array, more than 2000Kwhs, leaving us with a net surplus of 1,200Kwhs, or enough electricity to have driven an additional 4,800 miles on free sunshine.

Even without solar panels, it is still about 70 percent cheaper to drive on electric than on gasoline. These same 3,200 miles without solar power would only cost around $88 at the national average of 11 cents per Kwh. The average car in the US averages 23 miles per gallon on gasoline. To go the same distance on gasoline, it would take 139 gallon of gas. At an average of $3.80 a gallon for regular, that same distance would cost about $528.

On average, the Volt gets an average of 4 miles per Kwh of electricity. Depending on our driving skills and the time of year, it can be as low as 3 miles per Kwh in the cold winter with the heater running, and as many as 6 miles per Kwh in the spring when there is no need for air conditioning.


The main point is this. The sun produces electricity when its photons strike the soft silicon atoms in the solar panels on the garage. These electrons are then stored in the 400-pound lithium ion battery in the car. Since we are both retired now, we rarely travel more than 35 to 45 miles in any given day. However, since there have been a few times when we went over those distances, the gasoline engine kicks in silently affording us the opportunity to travel and additional 272 miles on the 9.3 gallons of gas in the gas tank. If at that time we wanted or needed to go any further, we would just need to pull into a regular gas station, and refill the gas tank and off we'd go.

On a regular 120-volt wall outlet, it takes about an hour for the battery to acquire enough electricity to drive an additional 5 miles, or nine hours to drive up to 45 miles on electric. With a 240-volt Level 2 charger, the time is cut in half. There are at least three Level 2 chargers in Chambersburg today.

Our car's dashboard indicates it has used 1.8 gallons of gas total. We have only used a total of nine-tenths of a gallon of gas. The remaining gas miles were put on by the manufacturer when the car was being driven around the test tack right after production.

The car weighs about 3, 500 pounds. It is capable of doing a top speed of 98 mph, although we've never tested it to make sure. It will go from zero to 60 in just over 8 seconds. It accelerates almost silently from a dead stop, very quickly, as the electric engine has instant torque. It has a safety rating of five stars.

One of the questions we get ask most frequently is how much did everything cost (the eight solar panels and the car).

The answer comes to a total of about $47,000 with a tax credit of $7,500 and $3,500 grant from the state Department of Environmental Protection. It was a total of around $11,000 off the sticker price of the car alone, not including sales tax, registration fee, etc..

We ordered the car with all the whistles and bells. However, the base price of the car sells at about $39,900. I go on to explain to those who are startled at the final price of everything that these prices will fall dramatically as more people begin to realize the longer term economic benefits of producing their own clean power and driving for free for the next 25 to 40 years.

It is like buying your own version of a regular gas station pump, only this one refills itself over and over year after year for decades at no additional cost.

With the price of gas going up seemingly almost every day, and the price of the solar panels and plug-in electric and plug-in electric hybrid cars decreasing every year, it should be reassuring to know that we can now look forward to the day when we can all become our own energy producers and live more less costly and more independent lives. 

I hope I have answered most of your questions about driving on sunshine. If not, please feel free to stop us anytime when we pull in someplace and ask. If we aren't able to answer you, you will have an opportunity to talk to an expert on sun powered electric cars at the upcoming Energy & You seminar at Wilson College on Feb. 9, in the new Brooks Science and Math Auditorium. So, mark your calendars and come see and talk to other electric car owners and the newest new electric car models all in one place.


Wayne Mackey, Chambersburg, is president of the Franklin Renewable Energy Association.