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Chevy Volt E-Flex Electric Hybrid Concept Car Flexible Fuel Electric [Plug-In] HybridsWhy No Plug RequiredPlug in my hybrid car? Why, you ask? The reasons are simple and the technology doable today, but first let's make one thing clear. The current crop of hybrid cars from Toyota, Honda, Ford and Lexus do not need to be plugged in to recharge their batteries. In fact, they can't be plugged in. Anxious to not have their cars confused with pure electric cars, carmakers have gone to great pains and expense to reassure potential buyers that their products have none of the limitations associated with battery-only cars, including having to plug it in at all. Instead, the batteries in today's gasoline-electric hybrids are kept recharged by an engine-driven generator. In addition, hybrids can also make use of the vehicle's own kinetic energy. Apply the brakes on your Prius or Insight or Escape and you actually engage the generator, which not only makes electricity, but actually helps slow down the car. You get back some of the energy (between 10-50% depending on how "mild" your hybrid is) you expended to move the car down the road and save wear-and-tear on your brakes at the same time. Cool, huh? CO2 Impact If we run cars off of electricity, won't that generate more greenhouse gases? No. They will generate significantly less. Here's why. If your car gets 20 mpg, you will generate almost 24 pounds of carbon dioxide driving 20 miles, while burning one gallon of gasoline. By contrast, a 20-mile-range plug-in hybrid might consume 5kW hours of electricity. Given transmission line and battery losses, it would take about 5 pounds of coal to go the same distance. Depending on how much coal and natural gas your utility burns compared to other non-CO2 fuels like hydroelectric power or wind, every kilowatt might generate about 1.4 pounds of carbon dioxide. That's just 7 pounds to drive those 20 miles on electric power-only compared to the 24 pounds of the gasoline-only car. And since ethanol is virtually CO2-neutral, a flexible fuel plug-in hybrid would produce two-thirds less CO2 emissions than a gasoline-engine car.
Electric Hybrids -- An Idea Whose Time Has Come
What we call an "Electric Hybrid", also known as a plug-in hybrid, grid-connected hybrid, gasoline-optional hybrid or just PHEV, works pretty much the same as your conventional hybrid, but with one big exception: it has a bigger battery pack. Take the much-in-demand Toyota Prius, for example. It has a 201 volt, 1.3kWh battery pack mounted under the rear passenger seat. It is a technological marvel all by itself. If the battery is fully charged and the engine warmed up, you can drive around the block without the gasoline engine turning on at speeds up to 42 mph. In effect, you're driving an electric car, and it's great for creeping along the congested 405 in Los Angeles. But wouldn't it be great if you could go further than a kilometer or two? We could if we replaced that 1.3kWh, Panasonic NiMH battery pack with sometime a bit larger, say 9kWh? What would that -- and some nifty computer code hacking -- do for the Prius? That's exactly what a California non-profit and small R&D company wanted to find out. The California Cars Initiative and EnergyCS have built prototype Electric Hybrids; CalCars building the first prototype, which they call "PRIUS+", with affordable, but heavier, low-energy density batteries, which will be replaced with NiMH; and Energy CS, using lighter Lithium-ion batteries. In the case of Energy CS's Electric Hybrid Prius, the engineering teams estimates that the car, if carefully driven, can get between 120-to-180 mpg; while using only 115-150 Whr per mile. The last part, Watt hours per mile, is important. Here's why. The 9kWh Lithium-ion pack provides enough energy to propel the car at freeway speeds for about 60 miles or so -- a really exciting improvement. At that point, the car returns to normal hybrid operation, running the gasoline engine for most of the time and getting about 50 mpg. In effect, you didn't burn a little over one gallon of gasoline for the first 60 miles or so, as long as you don't go faster than 40 mph[1]. Instead, you consumed something less than 9kWh of electricity. Why less than 9kWh? It's a safety and durability precaution so you won't fully discharge the battery and shorten its life. So, let's say you used 80% of the 9kWh. That's 7.2 kiloWatt hours. Now comes the fun part. Let's say you live in a city where electricity costs you 10 cents a kilowatt hour. To travel that 60 miles, it cost you 72 cents compared to the current national average price of gasoline at about $2.20/gallon in the US (as of April 2, 2005). In effect, for the same $2.20, you could drive up to 180 miles -- on three successive days, of course -- giving you the equivalent of 180 miles per gallon. Nifty, don't you think? Better yet, you generated no smog-forming tailpipe emissions and used American-produced energy including renewables, nuclear, coal, and natural gas, and virtually no imported oil. Can you start to appreciate the economic, environmental and national security implications here? To learn even more about the benefits of hybrids that you can power from your home, see All About Plug-In Hybrids on the CalCar's web site.
RESOURCES
Organizations California Cars Initiative EnergyCS Electric Power Research Institute Institute for the Analysis of Global Security Set America Free Plug-In Partners Plug-In Austin Plug-In Consortium Plug-In America eDrive Systems UC Davis Hybrid Team NREL Forums Electric Hybrid Forum Papers Benefits and Impacts of Hybrid Electric Vehicle Options [EPRI] Benefits and Impacts of HEV Options for Compact Sedan and SUVs [EPRI] Advanced Batteries for EVs [EPRI] Biofuels: Growing Energy [NRDC] Energy Future Coalition Letter James Woolsey (6-Apr-05 Testimony) James Woolsey (8-Aug-05 Testimony) Oil End Game Carrying the Energy Future Oil Security: Policy Paper by Committee for the Present Danger Take This Car and Plug It [pdf] Plug-In Partners Jan 24, 2006 Press Conference Transcript Plug-In Hybrids: Electrifying Transportation [E-Source] MP3 Audios Felix Kramer / Science Friday (22 Apr 05) James Woolsey / Diane Rehm Show Pt 1 (21 Apr 05) James Woolsey / Diane Rehm Show Pt 2 (21 Apr 04) MP3 Audio Plug-In Partner Press Conference Videos KTTV (9 May 05) Plug-In For America (.WMV)
Do I Have to Plug It In?
Of course not. That's the point. You get to choose which energy source is right for you. If there's not enough energy in the battery pack, no problem, you can drive on gasoline... but at about three times the cost, remember. Like a battery electric car or your cellphone, when you get home at night, you'd plug the Electric Hybrid into a standard 110 or 220 outlet; the latter allowing you to recharge the car a bit faster, in case you care. Unlike most fully-electric cars, a night's charge from a 110V outlet is sufficient, and if not, it's not a problem. So, while you sleep, the power company uses cheaper, off-peak electricity to recharge your car, saving you even more money and helping them get more efficient use out of their investment. You'd wake up each morning with a "full tank" of "fuel". And depending on how much you use the gasoline engine for longer trips, you might have to refuel at a gasoline station maybe once a month, if that. Need to drive further than 60 miles in a day? Again, no sweat. The car will operate just like any other hybrid using a mixture of both internal combustion engine and electric motor(s) to wring out the most efficient performance from the car.
Now Add Flexible Fuels There will be times, of course, when you'll need to switch on the internal combustion engine, but even here there's a neat, environmentally sustainable way to do this by switching from gasoline to E85 ethanol, a blend of 15 percent gasoline and 85 percent ethanol made from plant matter, principly corn at the moment, but eventually from any plant waste. Using E85 instead of gasoline is also good for the environment because it generates 30% less carbon monoxide and 27% less CO2 than a comparable gallon of gasoline; and most of that CO2 is carbon-cycle neutral because it's derived from plants, which need CO2 to grow. (E85 generates 17.06 pounds of CO2 to create 15,500 BTUs compared to the 23.95 pounds for gasoline). Carmakers have built and sold millions of vehicles in America that can use E85 without modification, but no hybrids, so far. A flexible fuel plug-in hybrid would use only 15% as much gasoline as a conventional vehicle when running on its IC engine; the remainder would be made of renewable, carbon-neutral biofuels grown and processed in America.
When Can I Buy One? The appearance of this new EV World section reflects a shift in perceptions about these cars. Institutions ranging from utilities to state governments to environmental, national security and other groups are starting to call for the production of these vehicles. Meanwhile, small groups like CalCars and Energy CS hope to offer installed "kits" until the car companies come around. Eventually, EV World expects carmakers to offer an electric hybrid option that will let you choose which fuel you prefer to use: gasoline, biofuels or electric power. That's when we'll have real choice.
[1] A critical caveat: current plug-in hybrid conversions based on Toyota and
Ford hybrid-drive systems operate in electric-only mode under 40 mph. Try to drive
faster than this and the gasoline engine comes on.
Plug-in hybrids with electric-only operation at freeway speeds greater than
40 mph are still in development.
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