Solar for Williams Residence - Lincolnville, MEWe spoke to retired research biologist John Williams about his experience having us install a solar electric array, and then using that electricity to power a Chevy Volt in addition to all of his home’s electric needs.

Could you tell us a little bit about your background?  How did you get interested in solar?

I have been aware that the world would eventually run out of fossil fuels ever since growing up in the 60’s in California.

After going to graduate school to become a research biologist, I began a research program as a post-doc at Cornell University, and later at the DuPont company in Delaware, to genetically engineer photosynthesis in  blue-green algae to make hydrogen from sunlight and water.  A worthy goal, yes, but far too ambitious for the times.

Much more needed to be learned about the fundamentals of the photosynthetic process itself, and our work necessarily moved in this academic direction for the duration of the project.  Meanwhile, physical scientists and engineers were making headway in developing practical solid-state solar panels.   And all during this time, we have been burning fossil fuels at increasing rates, hastening the day when supplies will run short and, as we now understand, driving up global temperatures from greenhouse gas emissions.

So what pushed you to go from solar enthusiast to solar customer?

We began construction of a 1,600 sq ft retirement home in Lincolnville, Maine, in late 2011 while still living in Nebraska.  In making plans for the new house, we noticed that PV prices had been dropping precipitously.  Energy modeling calculations showed that a grid-tied PV array should be capable of supplying all our domestic energy needs, including space heating and cooling, hot water, and appliances.   Even with this full load, we realized there was still open space remaining on the roof to add more solar panels that could be used to power an electric vehicle.

We were both surprised and excited to realize this was even a possibility and, in particular, that it made economic sense.  The house is all-electric, with a propane powered generator as back-up in the event of power grid outages.  We therefore sited the house to face due south with a roof pitch of 45 degrees, ideal for a solar array.

How Did You Choose ReVision Energy?

Researching on the internet from Nebraska in 2009, I saw that ReVision was a major installer of PV systems in Mid-Coast Maine.  On ReVision’s website, I read about an earlier installation in Lincolnville.  I later contacted the homeowners and learned that, as in my own situation, they had also contracted their solar installation from a distance.  They had good experience working with ReVision Energy, and were pleased with the results.

What Was the Process Like? 

A 7.6 kW array of 33 roof-top solar panels was installed by ReVision Energy in February, 2012.  We were in Nebraska at the time, but our house construction contractor was onsite.   It was a busy day, with both the ReVision crew and the roofers working simultaneously.  It seemed that once a patch of roofing was installed, it was covered immediately in solar panels!

When did you get the electric car?  How has the combo worked out?

Electric cars have been available only since about 2011.  In June 2013, we bought a Chevrolet Volt from Fuller Chevrolet in Rockland.  The Volt has both a battery and a small “range-extender” gasoline engine to alleviate concern about running out of electric charge while on the road.   We put about 12,000 miles on the car in the first year.

In the latest JD Power survey, the Volt ranks as the most reliable vehicle in the compact car class, outperforming every gas-only vehicle in class including the Toyota Corolla and Honda Civic.   While the all-electric range is specified at 37 miles, in practice our Volt typically achieved 52 miles in the warmer months of spring, summer and fall, and at least 34 miles range in the dead of winter.  Combined electric and gasoline range is around 320 miles.

Given that most of our trips are shorter than the electric range, in warm weather we can go weeks at a time without burning any gas.  In winter, the gas engine runs periodically to keep the batteries warm. On longer trips, the engine runs continuously to charge the battery.  Overall mileage in our first year was 113 mpg (i.e., 113 miles electric and gas combined per gallon of gas consumed).  Electric-only mileage was about 0.3 kWh per mile.

Since there are no public charging stations in our area, we installed a 240-volt charger in the garage when we bought the car.  A full charge takes 4 hours.  In April 2014, we installed an energy monitoring system to track household energy use.   To compare, from April 8 to June 5 the car charger consumed 427 kWh, our 40 gal electric hot water heater 447 kWh, and 182 kWh was used in total by the electric clothes dryer, electric kitchen range and two Fujitsu electric heat pumps for house heat.

So far, our PV array has provided all of the electric power needed to run both the house and the Volt.  We take pride in our new-found energy independence.  We didn’t think such a thing would even be possible until we began planning for our move to Maine.