Making the Electric Vehicle Connection
Frequently Asked Questions
Which charging station should I buy?
New plug-in vehicles come with chargers located inside the cars, plus cords and other equipment to plug into convention 120-volt electrical outlets. For faster charging, though, many drivers will want to buy Electric Vehicle Service Equipment (EVSE), known informally as a charging station, in order to plug into a 240-volt outlet. All come with the same "J connector" that should allow any plug-in vehicle to connect to any charging station.
Can electric vehicles self-charge?
Simply: No. Many people have proposed adding generators to EVs to allow the vehicles to partially recharge themselves. Some suggest generators on the wheels or drive shaft while others suggest small wind turbines behind the grille or on the roof. In each case, more energy would be consumed to turn the generators than could ever be recaptured. Attempting to generate while driving would result in a net loss of range.
There is no free lunch. Energy conversions are never 100% efficient, so every time we convert one form of energy to another, we lose some of that energy. We lose energy when we charge an EV's battery from the wall outlet. We lose energy when we take charge out of the EV's battery to push the car down the road. If we tried to convert the energy from the moving car back into battery charge, we would again lose energy.
Installing a generator on an EV would be akin to driving with the brakes on. For this reason, modern hybrids and EVs only recapture electrical charge when slowing down. The kinetic energy of the vehicle in motion is partially converted -- by the electric motor working in reverse -- into electricity that can be added back to the battery. This advantageous process slows the vehicle by capturing the vehicle's kinetic energy that is normally wasted to heat with traditional brakes. The problem comes when we do NOT want to slow down while simultaneously converting the kinetic energy of the car into battery charge. Spinning a generator will always require energy input. And that energy input will always slow the vehicle. To overcome this "slowing force" caused by the generator, additional energy must be consumed from the vehicle's battery to maintain speed. Because of the conversion losses mentioned earlier, more energy will be consumed than will be replaced. The ironic result of "self charging" would be a net loss of charge (resulting in shorter range).
Do plug-in vehicles emit electromagnetic radiation?
Data suggest there are no harmful electromagnetic emissions from plug-in cars. There is no broad agreement in the United States over what level of exposure to electromagnetic fields may constitute a health hazard, and there are no federal standards for allowable exposure levels. A National Institutes of Health reportshows (on page 41) that electric cars and buses have lower electromagnetic fields than conventional gasoline cars, similar to findings reported in a 1999 study by the U.S. Department of Energy.
Is the quiet nature of electric vehicles a hazard?
Electric vehicles are most certainly not silent. At parking-lot speeds they make as much noise via various fans, pumps and tire noise as most modern internal-combustion engine vehicles. At high speeds the wind and tire noise is comparable to any car. And like so many other issues surrounding the EV, this "problem" was addressed years ago. The EV1 had a back-up warning, as well as a pedestrian alert that could be activated by the driver when needed.
Adding a constant noise to the cars would only serve to increase ambient noise levels, subsequently lowering individual awareness and increasing noise pollution in our environment. By making all cars quiet, we would be safer than by making quiet cars louder. Ultimately, it's the driver's responsibility to operate any vehicle safely.
Can we put solar panels on an EV?
Putting solar photovoltaics directly on EVs is nice but not adequate. Most solar panels would add too much weight to an EV to be worthwhile. Some newer, lighter, flexible PV technology could generate power for interior climate control or minor tasks, but not enough to power a car a significant distance. Gotta have that plug.
Where do you recharge a plug-in vehicle?
Most people recharge overnight in their own garage, carport, or driveway, but there are public chargers for electric cars as well in parking garages and shopping centers. Federal, state, and local governments and Air Quality Management Districts have been funding installation of thousands of charging stations since late 2010. See www.plugshare.com to find chargers in your area.
How much does it cost to charge a plug-in vehicle?
Much less than it costs to buy gasoline. Exactly how much will vary depending on the vehicle and electricity rates. On average, it will be less than $1 to charge a plug-in hybrid and $2-$4 for an all-electric car. Your overall energy bill will be lowered by driving with electricity. EVs are so efficient that the cost per mile driven is significantly less than with a gasoline-powered car. For instance, a 2002 Toyota RAV4 will travel 100 miles on 4 gallons of gasoline. At $2.50/gallon, this is $10.00. A 2002 Toyota RAV4-EV will travel 100 miles on 30 kWh of electricity. At 10 cents per kWh, this is $3.00.
Are electric cars efficient?
EVs are the most efficient cars on the road. See the federal government's report on energy use:
Toyota RAV4 EV: 887 BTU/mile (rated 112 miles per gallon equivalent)
Toyota Prius: 2250 BTU/mile
Toyota RAV4 Gas: 4423 BTU/mile
Where do batteries end up? In landfills? Or recycled?
Vehicle batteries have an excellent reycling record that will get even better with plug-in vehicles. Every car in the world has a lead-acid battery, the most toxic metal used for batteries. Even with its low value as scrap, the recycling rate for lead-acid batteries is about 98% in the U.S. Plug-in vehicles use newer battery chemistries such as NiMH and Li-Ion. Their metals are inherently more valuable than lead. It is illegal to dispose of these batteries in a landfill and their value will ensure that they are recycled. But even before they're ready for recycling, plug-in vehicle batteries will have a second life.
How often do you have to replace the batteries?
Not for many years. GM and Nissan offer warranties covering 8 years or 100,000 miles of driving on the lithium-ion batteries in the Volt or the Leaf. Nickel-metal hydride batteries (NiMH) in the previous generation of EVs are proving to have very long lives. Several electric cars with over 100,000 miles have been reported with virtually no range degradation.
How long does it take to charge a plug-in car?
That depends on the amperage of the charging system and the size of the battery. Keep in mind that most of the time, the battery will not be empty when you plug in, thus reducing charging time. To recharge a completely empty car battery from an ordinary 120-volt socket, the Chevy Volt plug-in hybrid would need 10 hours and the Nissan Leaf EV would need 20 hours. Using a faster 240-volt outlet and a charging station, the Volt recharges in about 4 hours and the Leaf in 8 hours. Some states are beginning to install fast-charging stations along highways that can recharge a car to 80% of battery capacity in less than 30 minutes.
What happens when the batteries run out of power?
You charge them back up. When electric vehicles (EVs) and plug-in hybrids (PHEVs) are commonplace, charging stations will be everywhere, and thousand of them are being installed in the coming year thanks to government stimulus funds. Restaurants, grocery stores and other retail establishments will offer free or low-cost charging as enticements to get customers. Of course, anyone with access to a plug at home will set the car's timer to charge late at night, when cheap surplus power is readily available. Studies indicate that 80% of Americans have ready access to plugs where they park at night. PHEVs will not need to be charged since their internal combustion engine allows the same range as gasoline cars for long trips. However, to minimize pollution, cost, and the other ills associated with the use of oil, PHEV drivers would do well to plug in whenever possible to maximize the use of the electric grid.
Are plug-in vehicles dependable?
Battery electric vehicles are the most dependable vehicles. Well-made production EVs have the potential to last as long or longer than gasoline automobiles, with less regular maintenance. There are many fewer moving parts in an EV, and therefore less ongoing preventative maintenance. Brake life is significantly extended since the motor is used to slow the car, recapturing the kinetic energy and storing it back in the battery. Electric motors will outlast the body of the vehicle. Major automakers are offering warranties on the batteries of 8 years or 100,000 miles of driving.
Can I charge a plug-in car with solar or wind power?
Yes. The cleaner the power, the cleaner the car. Using solar photovolteics (PV) or wind power at your home or business makes even more sense with a plug-in car. The investment in solar panels pays off faster when the solar power is not only replacing grid electricity but replacing much more expensive gasoline. EVs typically can travel 3-4 miles (or more) per kWh of electricity. If you drive 12,000 miles per year, you will need 3,000-4,000 kWh. Depending on where you live, you will need a 1.5kW-3kW PV system to generate that much power using about 150-300 square feet of space on your roof. Utility credits for the daytime solar power can offset the cost of charging the car at night. If solar PV isn't feasible at your home, find out if your utility offers a green energy option.
To see if you can get green power in your area, check the U.S. Department of Energy's Buy Green Power locator.
Are the batteries ready?
Yes. According to an Electric Power Research Institute report, battery durability testing sponsored jointly by EPRI and Southern California Edison demonstrate that current lithium-ion batteries are likely to retain sufficient capacity for more than 3,000 dynamic deep-discharge cycles (about 10-12 years of typical driving.) Major automakers are offering 8-year, 100,000-mile warranties on the batteries of today's plug-in vehicles. Put lots of batteries in a car -- as in the Tesla Roadster -- and you can drive 250 miles on a charge. As with any new technology, the cost of EV batteries will become even more affordable once they're in mass production. Research continues to explore multiple newer battery chemistries that promise an exciting future for plug-in vehicles.
What kind of gas mileage can I get in a plug-in hybrid (PHEV)?
That depends on the size of the car, the size of the battery, and how you choose to drive. As with any car, the larger and heavier the vehicle, the lower the efficiency. If you have a PHEV with a 40-mile range in EV mode, and you rarely drive more than 40 miles without charging, you would almost never need gas. Your gas mileage could improve to several hundred miles per gallon, plus electricity. Using the U.S. Environmental Protection Agency's standard formulas to calculate fuel economy, the Chevy Volt PHEV averages over 100 mpg, CNet's Cartech blog reports. If you choose to run the Volt on nothing but gasoline, fuel economy would drop to about 48 miles per gallon. Alternatively, in an all-electric car, you'll never buy gas. For most people, an EV with a 100-mile range between recharging will be sufficient. For those that routinely drive long distances, a PHEV may be the best choice.
How is fuel economy determined and reported for electric vehicles?
What’s Reported: The fuel economy label for all-electric vehicles (EVs) includes all of the same information as that listed for gasoline vehicles (fuel economy, fuel cost savings, annual fuel cost, and emissions). However, EV labels list fuel economy using miles per gallon of gasoline-equivalent (MPGe), sometimes referred to as miles per gasoline gallon equivalent (MPGGE). MPGe represents the number of miles a vehicle can go using a quantity of fuel with the same energy content as a gallon of gasoline. MPGe is a useful way to compare gasoline vehicles with vehicles that use fuel not dispensed in gallons. EV labels also include the following information:
Vehicle Charge Time: Indicates how long it takes to charge a fully discharged battery using Level 2, 240-volt electric vehicle supply equipment.
Driving Range: Estimates the approximate number of miles that a vehicle can travel in combined city and highway driving before the battery must be recharged.
Fuel Consumption Rate: Shows how many kilowatt-hours (kWh) of electricity an EV would use to travel 100 miles. Like gallons per 100 miles, the kWh per 100 miles relates directly to the amount of fuel used. It is an estimated rate of consumption rather than economy (measured in miles per gallon [MPG] or MPGe), which allows for more accurate energy usage comparisons between vehicles.
What’s Tested: To test EV fuel economy, the vehicle battery is fully charged and the vehicle is parked overnight. The next day, the vehicle is tested over successive city cycles until the battery is depleted. The battery is then recharged and the energy consumption of the vehicle is determined by dividing the kWh of energy needed to recharge the battery by the miles traveled by the vehicle. MPGe is based on this figure. The process is repeated for highway driving cycles, and the combined city and highway fuel consumption and MPGe is based on the standard ratio of 55% city and 45% highway driving.
Plug-in Hybrid Electric Vehicles
What’s Reported: Like EVs, plug-in hybrid electric vehicle (PHEV) fuel economy labels include fuel cost savings, annual fuel cost, and emissions information. For PHEVs that can use either electricity or gasoline (but only one fuel at a time), also known as non-blended or series PHEVs, labels include information for the fuel economy of both fuel modes. The electricity information is identical to that of EVs, listing charge time, fuel economy in MPGe, and fuel consumption rate in kWh per 100 miles. The gasoline information provides fuel economy in MPG and fuel consumption information in gallons per 100 miles. PHEV fuel economy labels also include electricity only, gasoline only, and combined electricity and gasoline driving range estimates. For PHEVs that use electricity and gasoline at the same time, also known as blended or parallel PHEVs, fuel economy labels reflect the fuel economy, fuel consumption, and range of the vehicle when it uses its standard electricity and gasoline mix.
What’s Tested: Because series PHEVs can use either electricity or gasoline, the EPA determines a vehicle’s fuel economy and fuel consumption based both on its use of only electricity and only gasoline. To determine a PHEV’s electric fuel economy, the EPA issues testing methodology nearly identical to that of EVs. If the gasoline engine is required to complete the test cycle, the EPA methodology uses both the electric energy consumption and the gasoline consumption to calculate the MPGe values for the electric operation only. Vehicle testing for the gasoline operation of the vehicle is similar to any other conventional hybrid electric vehicle. Parallel PHEVs are tested using their standard mix of electricity and gasoline.
Are fully electric cars practical?
Electric vehicles (EVs) can meet the driving needs of many people, as proven by a decade of experience in driving EVs by the founders of Plug In America and other EV drivers. In the United States, well over 90% of drivers average less than 100 miles, the range of most vehicles in both the previous and current generations of EVs. Data from the U.S. Department of Transportation shows that most Americans average less than 30 miles per day. (See graph, below.) The occasional long-distance drive can be done with a second car that is a plug-in hybrid (PHEV), by access to vehicles in car-share services, or by renting or borrowing another vehicle.
Is plugging in a hassle?
Not at all. Plugging in literally takes less than 5 seconds of your time. There is no going out of your way to a gas station and jockeying for a pump. You can charge anywhere there is an electric outlet. Most EV drivers plug in when they get home and forget about the car until the next morning, when the fully charged car is waiting for them. The car's timer allows the car to recharge the battery overnight while the driver sleeps, at times of low electricity rates. Plus, thousands of public charging stations will be installed over the next few years to make it easy to add charge on trips away from home, too.
Will plug-in cars lead to more coal and nuclear power plants?
We won't need additional generating capacity in the U.S. electrical grid for plug-in cars for decades to come. During that time we can shift to cleaner, renewable power options that cause less environmental harm than fossil fuels and nuclear plants.
The existing electrical grid's off-peak capacity for power generation is sufficient to power 73% of commutes to and from work by cars, light trucks, SUVs, and vans without building a single new power plant if people drive plug-in hybrids, according to the U.S. Department of Energy. In addition, the existing nighttime electricity could be stored in plug-in vehicles and retrieved during peak-demand hours through vehicle-to-grid technology for use by the grid, helping to meet society's daytime power needs.
New power generation facilities should focus on clean, renewable sources such as wind, solar, biomass, and geothermal power. Combine these with the institution of energy efficiency measures throughout society, and we can meet the targets needed to avoid the worst effects of global warming without resorting to more coal or nuclear plants, according to the 2007 report Tackling Climate Change.
What about overall emissions, including the car and the power plant?
Even today, with more than 50% of U.S. power coming from dirty coal plants, plug-in cars reduce emissions of greenhouse gases and most other pollutants compared with other vehicle types.
EVs also allow you to use 100% clean renewable electricity from sources such as the sun or wind, eliminating emissions entirely. Getting more plug-ins on the road will incentivize our society to move more rapidly to replace fossil-fueled power plants with clean and renewable generating methods. EVs get cleaner as the electrical grid gets cleaner. Gas cars only get dirtier as they age.
Why would I want to plug a car in?
Three words: Cheaper. Cleaner. Domestic.
Cheaper: Electricity is much cheaper than gasoline (about a third of the current cost of
gas) and electric cars require next to no maintenance. (No oil changes, no muffler, no catalytic converter, etc. etc.)
Cleaner: Even on today's mainly coal-fired electrical grid, driving on electricity is cleaner than driving on gasoline. Plus, plug-in vehicles give you the option of driving on renewable electricity sources such as solar, wind, or geothermal energy. Driving on electricity produces less of the pollution that sickens and kills hundreds of thousands of Americans each year.
Domestic: Electricity is made in the U.S.A. By driving an EV, you don't have to give your money to oil companies, the politicians they support, and the foreign tyrants who control the oil supply.
Bonus: Plug-in cars are quiet, convenient, and fun to drive!