Like a lot of big city mayors, R.T. Rybak drives a city-owned car. But the Minneapolis mayor gets up to 79 miles per gallon. And when he’s not using the vehicle, he doesn’t just park the car.

He plugs it into a standard electrical outlet.

Rybak drives one of two “plug-in” cars known to be in use in the Twin Cities. They are powered by conventional gas engines and electric motors run by batteries that are recharged by plugging the vehicles into a 120-volt outlet.

“You know, if every car would just get 10 more miles more per gallon, it’d go far in reducing oil imports,” said Rybak as he guided his car through mid-day city traffic. “We’re told that for that to happen it’d take some far-out new technology, but what about this right here?”     
Rybak began driving a Toyota Prius shortly after taking office in 2001. The Prius and other cars like it are known as “hybrids” because they have both gas engines and electric motors.

Essentially, the standard hybrid’s gasoline engine is assisted by the electric motor in light-drive conditions.  Under normal driving conditions, the hybrid can get up to 45 miles per gallon.  Its batteries are recharged by “regenerative braking,” which means that energy used in slowing and stopping is converted to electricity that’s sent to the battery pack. 

However, a plug-in car has an additional lithium-ion battery that stores much more energy and, when charged, allows greater utilization of the electric motor and less reliance on the gasoline engine.  That pushes average fuel economy to about 80 miles per gallon. Industry analysts say that mileage figure could be doubled as plug-in car technology is perfected over the next two years.
  
Typically, a plug-in vehicle can go 35 to 40 miles between charges. But running out of a battery charge doesn’t leave the motorist stranded because the gasoline engine can be used to complete the trip — just like a conventional car.

Last October Rybak’s car was converted to a “plug-in” with a system sold by Hymotion of Toronto. 

$10,000 for conversion
The only other plug-in car in use in the Twin Cities is owned by the Hour Car, which is operated by the St. Paul Neighborhood Energy Connection (NEC). Mary Morse, NEC’s executive director, said the nonprofit has one plug-in car in its fleet of 14 electric hybrids that are available to members who prefer the cost-savings of short-term car rentals over ownership. (The city of Minneapolis is one of NEC’s clients.)

Morse said the plug-in battery requires from four to seven hours to recharge, depending on outside temperatures (a car left in a cold garage in winter takes longer). Converting the standard hybrid car to a plug-in vehicle cost $10,000. (Half the cost of Hour Car’s plug-in conversion was paid for with a demonstration grant from the Minnesota Pollution Control Agency.) Plug-in conversion kits for gas-electric hybrids are expected to be available at a much lower cost in the near future.

Within a few years consumers will be able to buy plug-ins cars from major brands. Chevrolet will introduce its electric Volt in two years, and last month Japan’s Toyota went to the heart of the U.S. auto industry, Detroit, to announce that its own plug-in electric Prius will be available at about the same time. In addition, Chrysler is making plans for an all-electric car.

The auto industry’s recent interest in electric cars is due to a changing market: ever-increasing gas pump prices have pushed demand for fuel-efficiency, and Chevy’s Volt has drawn Toyota into the high-stakes war for market share. Also, the 2008 Energy Act requires automakers to improve their fleet-average to 35 mpg by 2020. And the more high-mileage cars that manufacturers can get on the road, the more they can protect the high-profit market for gas-guzzlers — still desired by U.S. consumers who like their big, heavy machines despite their woeful fuel economy.
 
New-battery technology has emerged to drive down the cost of batteries and increase the driving range between charges. The lithium-ion battery — an enlarged version of the battery used in most cell phones and other small electronics — is just now coming into full development.
Rybak’s car gets nearly 80 miles to the gallon (less when driven on the highway). Toyota claims higher mileage with the lithium-ion batteries and other improvements.

Other fuel savers
Do consumers have to wait for plug-ins cars to realize much improved fuel economy?

The hybrid Prius is already available and showing up more and more on the road. It averages about 40 mpg overall, but more with in-city driving where braking and slowing act to recharge batteries and extend its operating period in electric mode.  Similar fuel economies are available with the Honda Civic, Nissan’s Versa   and Volkswagen’s Jetta TDI diesel. 

“Fuel economy is related to vehicle weight and horsepower,” said John Maples with the U.S. Energy Information Administration (EIA) in Washington D.C. “Remember that in the 1980s following the Arab fuel embargo, we had the Geo Metro and Honda Civic, both of which got 50 miles to the gallon. But the crisis passed, and Americans continued to do what they’ve always done and buy large cars with heavy components and lots of horsepower.” 

Over the years, the auto industry has successfully blocked implementation of fuel economy standards and obtained exemptions for large SUVs from the tighter regulations imposed on cars.

In 2006, cars in the United States averaged 20.4 mpg and consumed 136 billion gallons of gas. With 5 percent of the world’s population, the United States consumes a quarter of the world’s oil, half of it for transportation.

If, as Rybak hypothesized, cars in the United States averaged another 10 miles to the gallon, EIA projects that the nation’s fuel consumption would drop a third, annually saving nearly 45 billion gallons. The EIA said that if all cars would get 75 mpg like Rybak’s plug-in, the United States would save nearly 100 billion gallons of fuel every year, or 73 percent below current levels. 

There is nothing new about electric motors in transportation, and scientists say electric motors are twice as efficient as gasoline engines in converting energy.

But while studies show that plug-in cars reduce carbon emissions from passenger vehicles, there are increased emissions of harmful sulfur dioxide if the electricity source is coal-fired power plants.  

NEC’s Morse said that her organization subscribes to Xcel energy’s Windsource that supports power generation from wind.

Minneapolis has gone a step further. It has been selected  to receive a $2 million grant from Xcel Energy to build what would be the Upper Midwest’s largest solar array, with 3,000 panels generating 600 kilowatts of electricity. 

Rybak said that emission-free energy from the panels, together with solar arrays on other city buildings, would be used to charge the mayor’s car plus other plug-ins vehicles he expects the city to buy once they become commercially available. To reduce vehicle emissions in the city, Rybak has added 28 hybrids to the city’s fleet of cars.

Ron Way, a former reporter for several Midwest newspapers, covers the environment and energy issues. He can be reached at rway [at] minnpost [dot] com.