When gas-electric hybrid cars were introduced in North America in the late 1990s, they were hailed as an answer to growing concerns about climate change and oil prices. Since these cars run on both conventional gas engines and electric motors, they represent a decrease in fossil fuel consumption. The 2008 Toyota Prius gets 44 miles per gallon (mpg) overall [source: Consumer Reports]. This is a significant improvement over the fuel consumption of most conventional cars -- the 2009 Toyota Corolla XRS, for example, gets 22 mpg in the city and 29 mpg on the highway [source: JD Power].
While hybrids have become increasingly popular since their debut, they're not entirely perfect. Yes, they release less greenhouse gas (GHG) emissions and offer better fuel economy, but they still require fossil fuels.
Auto manufacturers aren't intent on using up every last drop of oil on Earth before new technology is debuted. On the contrary, it's in the carmakers' vested interests to give their customers what they want. And the auto industry's customer base is calling for cleaner, more fuel-efficient cars than ever before. Hybrid car sales in the U.S. increased 38 percent from 2006 to 2007 [source: AP].
But some consumers aren't waiting around for the auto industry. Many Prius owners who wanted even more fuel efficiency have converted their hybrids into plug-ins with modification kits or by adding batteries to the cars. Toyota campaigned against these modifications for several years. The company wanted to establish the hybrid's reputation as a regular car -- one that customers didn't have to bother plugging in. At last, Toyota relented to the growing demands: A factory-made plug-in version of the popular hybrid is due out in 2010 [source: WSJ].
A plug-in hybrid is a desirable car for environmentally minded drivers. Hybrids use gasoline to fuel generators that charge their batteries. Charging the batteries through an electrical outlet at home (instead of with gas on the road) saves fuel and reduces emissions. But there are drawbacks to plug-in hybrids and even all-electric hybrids that use no gas at all. By using electricity, these cars also demand fossil energy, and in a roundabout way, still pollute.
So is there a way to create an all-electric car you don't have to plug in? Find out on the next page.
Solving the Problems with Plug-ins
One of the problems with gas-electric hybrids is that they use gasoline to power the car at speeds of more than 15 mph. They also power the generators that recharge the onboard batteries. All-electric cars rely entirely on electricity and therefore emit no greenhouse gases (GHGs).
But electric cars have their own challenges, one of which is speed. An electric motor generally can't match the power and speeds of a car fueled by an internal gas combustion engine. This problem fell largely to the wayside (for well-to-do drivers, at least) with the introduction of the Tesla Roadster. This $100,000 all-electric sports car can go from 0 to 60 mph in less than four seconds and gets the equivalent of 135 miles per gallon of gasoline [source: Tesla Motors]. The Tesla also gets 220 miles per charge.
The Tesla isn't a hybrid, so like other electric cars, it must be plugged into an electrical outlet to recharge. This leads us to the biggest problem with plug-ins: the need for mass-produced electricity.
An all-electric, zero-emissions car still has a carbon footprint. The fossil fuel it takes to produce the car in the first place leaves a footprint. Since the car needs to be charged with electricity, it continues to demand fossil energy. That's because most electricity produced in the United States is created by burning fossil fuels like natural gas, coal and oil. Coal alone accounts for half the electricity produced in the U.S. [source: National Mining Association]. So when you plug in your electric car, you're still creating GHG emissions.
Researchers have suggested that hydrogen is a possible candidate for the future all-electric, no-plug car. Even electric cars run on hydrogen need fossil-fuel input. The hydrogen fuel distributed at the pump will likely be created by burning methane.
The ultimate goal, then, is to create an all-electric car that requires no fossil fuels. The challenge is to come up with a way to generate electricity onboard using renewable forms of energy. The likeliest solution is solar power. At least one company is already at work creating the first electric-solar hybrid.
The French transportation company Venturi has created the Astrolab, a two-seat convertible car that can reach speeds of about 75 mph [source: Gizmag]. The car maximizes space with a horizontal, rectangular panel that surrounds it. The panel features nanoprism photovoltaic cells for capturing solar energy and converting it into electricity. So what's the hitch? The sun doesn't always shine where your car is parked.
If electricity were produced in mass quantities through wind or solar power, then plugging in all-electric cars would pose no environmental problem. But Venturi isn't waiting for electricity providers to catch up. The company offers another electric car, the three-seat Eclectic, which has photovoltaic cells on its roof that capture and store energy. The car, which looks like a cross between a golf cart and a Ford Model T, not only runs on solar power: It comes with an optional portable wind turbine. You can set up the turbine beside the car when it's parked, and it uses wind power to generate electricity to recharge the car's onboard batteries [source: Venturi].
Venturi isn't asking customers to hedge their bets, however. Both the Astrolab and the Eclectic come equipped to plug into an electrical outlet to juice up. It looks like it may be a while before we ditch our plugs with full confidence.
For more information on electric and hybrid cars and other related topics, visit the next page.
Related HowStuffWorks Articles
More Great Links
- Boschert, Sherry. "The secret life of plug-in cars." Yes Magazine. Spring 2008. http://www.yesmagazine.org/article.asp?id=2282
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- Hakim, Danny. "Hybrid-car tinkerers scoff at no-plug-in rule." New York Times. April 2, 2005. http://www.nytimes.com/2005/04/02/business/02plug.html
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