The volatility of gasoline prices over the past year (2008-2009) and the struggling of conventional motor vehicle companies such as General Motors to maintain sales during the economic downturn have prompted a resurgence of interest in electric cars. Several new electric car designs are currently under development and should be available in showrooms in 2010.
These new designs include the Nissan Leaf, the plug-in Toyota Prius, and the Chevrolet Volt, which are all sedans built with the ‘typical’ consumer in mind. How do these electric cars differ, and what factors should consumers weigh when considering buying an electric car?
Design of the Nissan Leaf, Plug-in Prius, and Chevrolet Volt
The Nissan Leaf is a fully battery-powered electric car; therefore, the only way to ‘fuel’ the car is to plug it in and wait for the battery to charge. Using a standard (110-volt) home electrical outlet, it will take between 4 and 8 hours to fully charge the battery. However, Nissan is planning a network of quick-charging stations that would be capable of charging the battery to 80% capacity in 26 minutes, according to the official Nissan USA website.
On September 9th, the Toyota Pressroom website reported that the plug-in Toyota Prius will be unveiled at the Frankfurt Auto Show (Frankfurt, Germany, September 17th to September 27th 2009). Preliminary information indicates that the plug-in Prius is identical to current Prius models in that it exhibits an energy-recapturing battery coupled with the gasoline engine (a “hybrid synergy drive”). However, the plug-in Prius will exhibit a lithium ion battery instead of the nickel metal hydride type of battery used in the current Prius.
In both current and plug-in Prius models, the car runs solely on the battery when the engine and catalytic converter are fully warmed up. In both models, the battery is recharged during braking (“regenerative braking”), but the new plug-in model would allow the battery to recharge by plugging the car into an electrical socket as well. Recharge time is estimated to be about 180 minutes if the car is plugged into a 110-volt outlet, and approximately 100 minutes if a 220-volt outlet is used, according to the Toyota Great Britain Media website (reported on September 10th, 2009).
In contrast, the Chevrolet Volt is an electric car equipped with a range-extending gasoline engine. This means that, unlike the plug-in Prius (or any other hybrid car), the Volt’s wheels are never directly propelled by the gasoline engine. Instead, the Chevrolet Volt is powered by a battery, but a small gasoline engine is used to recharge the battery while the car is in motion. Dr. Lyle Dennis, author of the non-GM affiliated website gm-volt.com, reports that the Volt can fully recharge in 6.5 hours if it is plugged into a standard (110-volt) outlet, or 3 hours if it is plugged into a 220-volt outlet.
How Far Can the Nissan Leaf, Plug-in Toyota Prius, and Chevrolet Volt Drive on a Single Charge?
The Nissan Leaf, plug-in Toyota Prius, and Chevrolet Volt differ greatly in the driving range each could accomplish on a single charge. The official Nissan USA website states that the Leaf can cover 100 miles on a single charge. In contrast, a September 10, 2009 press release from Toyota Great Britain indicates that the plug-in Prius will be able to drive just 12.5 miles on a single charge (after 12.5 miles of driving distance, the Prius will shift to gas-only mode, recharging its battery via regenerative braking until it is plugged into an outlet).
According to General Motors (GM), the Volt will be able to drive for 40 miles before the battery capacity is significantly reduced (drained to 30%) and needs to be recharged. At this point, the range-extending gasoline engine will begin to generate electricity to replenish the battery.
Environmental Impact of the Nissan Leaf, Plug-in Toyota Prius, and the Chevrolet Volt
A fully electric car such as the Nissan Leaf emits no carbon dioxide or nitrous oxide, which are important greenhouse gases linked to global warming. Carbon monoxide, an air pollutant with a significant negative impact on human health, is also not released by electric cars.
A plug-in hybrid like the Toyota Prius, or a battery-powered car like the Chevrolet Volt with a range-extending gasoline engine, will not produce harmful emissions as long as the car operates in battery-only mode. If the gasoline engine of either car operates, then carbon dioxide and nitrous oxide will be released.
It is important to note that an electric car is only as ‘green’ as the energy source used to recharge its batteries. For example, if an electric car battery were recharged in a region where coal-burning power plants are the primary energy source instead of clean energy such as wind, solar, or geothermal power, then operating the car would not be free of environmental impact.
However, according to the Electric Drive Transportation Association, there would still be a net environmental benefit associated with driving an electric car whose battery is charged using coal-derived electricity versus a gasoline-burning car.
How Much Do the Nissan Leaf, Plug-in Toyota Prius, and the Chevrolet Volt Cost?
Official prices for the Leaf, plug-in Prius, and Volt are not yet available. However, according to GM Vice Chairman Bob Lutz, the Chevrolet Volt will cost around $40,000, but a federal tax credit might reduce the amount consumers have to pay to $32,500 ("Chevy Volt: GM's 230 mpg Moon Shot", US News and World Report: Rankings and Reviews). Therefore, consumers will pay a premium for electric cars compared to gasoline-powered cars of a similar size. This is not surprising considering that the battery pack alone for an electric car might cost as much as $25,000, according to the article "The Electric-Fuel-Trade Acid Test" in The Economist (September 5th -11th, 2009).
Molly Markey - Education PhD, Earth and Planetary Sciences, Harvard University (2006)BS, Geology (Paleobiology) and Russian, Bowling Green State ...
