Mr. Green Car: Charging pyramid aims to increase electric vehicle use
By Allen Penticoff
A frequently-asked question about driving our Chevy Volt is, “What does it cost to charge it?” This is a fair question, and my usual answer is about $30 per month or 2 cents per mile. However, in the transition to a world where there will be more electric cars, we will need to discard the habits of the gasoline-fueled vehicle and approach keeping our cars filled up in a different fashion.
General Motors (GM), the U.S. Department of Transportation (DOT) and others have done research that shows 90 percent of American workers have a 32-mile round-trip commute to their place of employment. Data show the average person drives no more than 40 miles per day. With this information, GM engineered the Volt to have a battery capacity that fit most workers’ lives without running out.
With a gas-powered car, one drives for several days before the fuel gauge indicates it is nearing empty. Then, one pulls into one of the many public refilling stations and fills up the tank.
With an electric car, one needs to refill with cheap electric power every day while the car is “resting” at home during the night using standard 110-volt sources. Eight hours of charging will yield about 32 miles of driving. If your electricity provider offers off-peak charging rates, it can be even cheaper.
However, electric car drivers (those who don’t have a back-up engine like the Volt) have some “range anxiety” — or the little pit in their stomach that they may run out of battery power before they get home. So, GM and DOT looked into what would help more people use electric vehicles (EV) more. They came up with the “charging pyramid.”
In this pyramid, the least expensive charging is at home during eight hours of non-use charging, costing (based on 15 cents per Kwh for all numbers) 50 cents for off-peak charging. This is similar to my own experience, even without an off-peak rate.
The next level up the pyramid is peak-rate charging while the commuter vehicle is in non-use at work. Described as “Municipal, Corporate, Federal and State lots,” here, two to eight hours of charging would cost approximately 75 cents and give the electric vehicle another 32 miles of range (and probably a full charge for a Volt.) This would allow the EV commuter to do many more errands before returning home.
The last step up the pyramid is the more expensive quick-charging infrastructure needed at “Outreach and Education, Commercial and Retail” locations that “Reduce Anxiety” with “High Visibility.” An hour of high-speed (220 volts or higher) charging will cost the supplier about $1.50.
The push here is to encourage workplaces to provide for EV charging for employees. It does not necessarily have to be “free” charging. A small paycheck deduction for EV charging may be very welcome to EV owners. A more enlightened employer may wish to provide free charging to encourage employees to commute to work with an EV, and may even go as far as to source their power with solar panels. This REALLY is the direction we need to be going.
Workplace charging makes it possible to build EVs with smaller battery packs — and, thus, be more affordable for the average person. A Tesla S has more than adequate daily range, but it is an expensive car. A Volt can get by on a bit of gasoline, if needed. But if workplace and more public charging were available, you could take the engine out of a Volt and save some of the cost or put in more batteries (this should be a Volt option).
In the real world, right now, most EV/Volt owners are getting by without workplace or public charging, but there would be wider acceptance of EVs with the reduction of “range anxiety.”
Since April 1, our Volt has traveled 2,250 miles around Rockford on daily commutes, errands and trips with the engine coming on twice only briefly (and two “engine maintenance tests”) — having consumed one-10th of a gallon of gas in all those miles. We have anxiety that the engine might come on before a day’s use is over, as we strive to do all our running around on electricity alone.
To us, it does not matter that the Volt cost more to buy and that the reduced cost driving on electricity will be a long time in being recovered. We like driving on smooth, quiet and CLEAN electric power — and that is justification enough to own an EV.
From the July 9-15, 2014, issue