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Fill ‘er Up With Kilowatts

Electric cars have been the stuff of futuristic drawings and a favorite subject for daydreamers for decades. This time around, it looks like real electric vehicles may become commonplace within the next three to five years.

The push is on to develop this new technology due to mounting worldwide concern over greenhouse gas emissions. Everything we can think of to take better care of the environment and use energy wisely deserves our attention. Experts believe it could be a lot easier and more efficient to control emissions at a single central electric power plant instead of on millions of individual cars and trucks running on other fuels.

Plug-in electric vehicles, known as PEVs, offer a lot of advantages. But how quickly these new choices reach the marketplace—and whether American consumers will actually buy and use them—depends on many factors.

In a report compiled two years ago and released in mid-2007, the Electric Power Research Institute (EPRI), a nonprofit utility industry group, looked at the ways improvements in technology could help reduce greenhouse gas emissions.

Plug-in electric vehicles were one of the seven areas that EPRI investigated.

That report highlighted some of the practical problems that must be solved before these kinds of vehicles become common. Other studies continue to provide facts and figures that show PEVs offer many additional benefits. Let’s take a look at the latest developments.

How electric vehicles work
There are several different ways to power a vehicle with electricity.

In a hybrid electric vehicle (HEV), such as the Toyota Prius already in production, a conventional internal combustion engine produces enough surplus power to charge electric storage batteries within the vehicle. The electricity does not come from the utility grid. Depending on driving conditions, the car automatically shifts between one of the two propulsion systems. Sometimes the vehicle is moving due to power from the internal combustion engine, and sometimes the vehicle is moving due to power from the batteries. This type of arrangement is called a parallel hybrid. There are already more than 20,000 Toyota Prius HEVs on the road.

Plug-in electric vehicles are very different.

In a completely electric vehicle, such as a golf cart, the only power source and the only propulsion system is a set of storage batteries. In this kind of plug-in electric vehicle (PEV), the batteries are charged from an ordinary electric outlet.

It’s the same technique as charging up a cell phone battery. And it has the same limits—when the charge is used up, it’s gone, and the equipment stops working. The only way to re-charge the batteries in this kind of vehicle is to be near an electric outlet that’s connected to the grid. That means PEVs are not really practical for long distances.

However, PEVs are very useful for short trips in a compact area; many are already in use today on college campuses, around corporate headquarters and small neighborhood office parks, and at resort hotels. Gatormoto, a company in Gainesville, Florida, sells at least a dozen varieties of plug-in electric vehicles for these kinds of uses. Some are large and powerful enough to transport 15 to 20 passengers.

For longer distances along suburban streets and highways, more attention is being given to plug-in hybrid electric vehicles, known as PHEVs. These vehicles have a set of storage batteries that are charged from the electric grid. But they also contain a small gasoline or diesel engine. However, that conventional internal combustion engine never propels the car. It simply produces enough electrical energy to recharge the batteries so they don’t become exhausted while traveling. A PHEV always moves due to electric power from the batteries. This kind of arrangement is known as a series hybrid.

The Chevrolet division of General Motors has a concept car, the Volt, that would use this kind of technology. So far, this vehicle exists only in drawings, with no firm production dates announced. Other manufacturers are also working on the concept of PHEVs.

PHEVs are an improvement over battery-only vehicles because they make it possible to travel longer distances between recharging the batteries. They also make it less likely that a vehicle would become stranded on the roadside due to exhausted batteries.

That solves one technological problem—but there are still a lot of things that need improvement before plug-ins will become common.

Technology moves forward
One of the biggest challenges for electric cars involves the batteries. Small lithium-ion batteries are everywhere today—you’ve got one in your cell phone or your iPod, maybe in your digital camera. But this kind of battery has to be a lot larger to store and release enough energy to move a vehicle. Figuring out just the right combination of these huge batteries to provide the correct amount of power, and then where to put them within the vehicle, is a tricky design problem—there still has to be enough room for the driver, passengers, and cargo.

It takes about 1,000 pounds of today’s lithium-ion batteries to power a sedan-style vehicle. Another problem with the large batteries needed for an electric vehicle is the re-charging time—up to six hours.

The Advanced Transportation Energy Center, a research facility at North Carolina State University in Raleigh, will start working on these issues in June. Dr. John Gilligan, vice chancellor at NC State, says, “Our research objectives are to find ways to reduce the weight of the batteries, and to make it possible to charge them more quickly. During the next two years, we’ll test new components in our lab. These improved batteries and electronics could be tested in vehicles within five years.”

For those who don’t want to wait for plug-in cars to start coming off mass production lines, a variety of companies offer conversion kits and services that can turn a standard hybrid electric Prius into a plug-in hybrid electric vehicle. Interest in this sort of after-market, “do-it-yourself” technology is increasing, even though it typically adds $7,000 to $10,000 to the cost of the vehicle.

Four County Electric Membership Corporation, a rural electric co-op headquartered in Burgaw, North Carolina, recently converted a Prius into a vehicle with plug-in capabilities with help from the Advanced Transportation Energy Center and technology from Hymotion, a manufacturer of conversion modules.

Other electric co-ops plan similar demonstration projects, including Kentucky’s Blue Grass Energy in Nicholasville. Cathryn Gibson, vice president of member services and economic development, says, “Using a car powered by electricity from the grid is an opportunity for us to show our members how we can all do our part to be good environmental stewards.”

Additional benefits
Simply showing people that cars powered by electricity perform just as well as conventional vehicles is a valuable part of these demonstration projects. Consumer demand for these new cars will increase as people realize that PHEV technology can provide a safe, reliable way to travel.

That’s very important to automotive manufacturers who are often slow to make innovations. It takes a lot of time and huge amounts of capital investment to set up new production lines. Each car company has its own ideas about how many cars it needs to sell in a year’s time to make it worth investing in a completely new model. Economies of scale are also involved—if demand for the new vehicles is high, production numbers can be high too, and the per-car cost comes down. A recent survey by J.D. Power and Associates predicts that General Motors could sell 60,000 of its Volt concept electric cars if the sticker price is under $30,000.

Developing consumer demand, offering affordable pricing, and improving battery technology for plug-in vehicles are each important parts of the push to control emissions from the transportation sector. But exactly how much difference using plug-in electric vehicles will make for the environment depends on a few other factors.

Right now, the amount of electricity Americans use during any 24-hour period varies enormously in most parts of the country. More than 40 percent of America’s electricity generating plants operate at less than full capacity during the overnight hours, when demand for electricity is often very low. What this means is that we have already invested billions of dollars in an infrastructure that works at full capacity some of the time—but isn’t used at its maximum levels all the time. If plug-in electric vehicles are charged up overnight, during these off-peak times, that would improve power plant efficiency significantly.

Using electricity, which is produced right here in America, to power vehicles would also reduce reliance on fossil fuels imported from other countries. That has two big advantages. It means more American dollars stay within the American economy. Using electricity that travels through the grid also reduces the amount of fuel and road congestion used to transport conventional fuels from refineries to the consumer.

Measuring the trade-offs between using one kind of fuel and another is a complicated task. Assigning dollar values makes it even more complicated, but recent studies show that mass-produced plug-in electric vehicles will be much cheaper to operate than conventional transportation. When gasoline prices were at $3 a gallon, a study using the national average price for electricity of 8.5 cents per kilowatt-hour showed that the amount of electricity needed to operate a PHEV would be like rolling back the cost of gas to 75 cents a gallon. As petroleum prices continue to rise, electricity for vehicles becomes an even better bargain.

Engineer Mark Duvall, program manager for electric transportation at EPRI’s Palo Alto, California, offices, says, “EPRI recently completed the most comprehensive study to date with the Natural Resources Defense Council about the impact of electric vehicles. We found that large-scale adoption of plug-in electric vehicles would generate modest yet significant improvements in air quality throughout the entire continental United States. In every scenario we studied, from the year 2010 to 2050, plug-in hybrids could potentially reduce greenhouse gas emissions nationwide by up to 500 million tons per year by 2050.”

Electricity as a fuel continues to get cleaner over time. As a nation, we’ve already made tremendous strides in reducing a variety of emissions from power plants. As more renewable energy sources become part of the nation’s electricity supply, plug-in electric vehicles will become an even wiser energy choice.


To read more about electric vehicles and their potential effects on the environment, you can find a summary of a study by the Electric Power Research Institute at For a shorter explanation on the basics of electric vehicles, go to

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