We are frequently told these days about how soon we'll all be driving electric cars, or fuel cell cars, or hydrogen cars. The only thing coming out the tail pipe will be water. Is this actually going to happen? Sorry, no.
In the US in 2008, there are about 225 million cars and light trucks. These cars drive an average of about 11,000 miles per year, about 40 miles per day. The US uses a bit more than 8 billion barrels of oil per year, at a cost of about $800 billion per year. Each barrel of oil produces about 20 gallons of gasoline, the equivalent of about 750 kilowatt-hours of electricity. Notice that $75 of electricity is the rough equal of $60 worth of gasoline. This is not surprising as a lot of electricity is made in oil burning power plants. An average US driver burns about 30 barrels of oil, about 600 gallons of gasoline each year, at a cost of about $1800. We also burn a lot of oil in electric power plants, diesel trucks, airplanes, and home heating systems.
GM tells us that 78% of all cars go 40 miles per day or less. To recharge an electric car, the average driver needs to plug in for about eight hours drawing about 1,000 watts. 1000 watts is about the maximum you can draw from a normal electrical outlet. So, everyone who has an electric car wants about 8kwh per day, at a cost of roughly $1. If all 225 million cars in the US were suddenly electric, we would apparently need about three hundred new 5,000 megawatt power plants; that is we would need about 300 nuclear reactors. We have 146 nuclear reactors right now. Each nuclear reactor costs roughly $5 billion, so we need to come up with about o1.5 trillion dollars to build our new power plants. Nuclear reactors require a steady source of water for cooling, so are built on coasts or large rivers. California has about 10% of the US population, and about 840 miles of coast line. So, in California there would need to be 25 nuclear reactors built, one on the coast about every 35 miles. Oregon and Washington would need similar reactor plants. The Ohio, Mississippi, and Missouri rivers, 5000 miles total, would also have nuclear reactors spaced out at about thirty mile intervals, as would the Pacific, Atlantic and Gulf of Mexico coasts. These new power plants don't actually have to be nuclear - there's a lot of coal in the US, we could equivalently build 300 coal fired power plants, or any mix. Unfortunately, coal power plants make almost as much pollution as the gasoline burning cars they would replace.
Let's say instead of using electric power, we get everyone to burn hydrogen. Now we need to convert most of the 180,000 US gas stations to hydrogen, at perhaps a cost per station of $100,000, a total cost to gas station owners, oil companies, and / or society of $15-$20 billion. In addition, that hydrogen has to come from somewhere. We'll still need to build 1,000 nuclear reactors to convert water into hydrogen, then use trucks to bring the hydrogen to your local "gas" station. Engineers have a saying, "Tanstaafl," There Ain't No Such Thing As A Free Lunch.
Let's say we switch half of our cars over to electric. Our gasoline consumption would immediately cut in half. Since the US uses about 25% of all the oil produced in the world, half of that for gasoline, this would cut world-wide oil consumption by 6%. Unfortunately, China is increasing their use of oil by 1% of the world supply per year. So in six years the growth in China's oil consumption would cancel out the savings made by the US cuts in oil consumption. Perhaps we could talk China into building themselves 500 to 1500 new nuclear reactors and building electric cars.
What's going to happen? Without question, the price of oil is going to stay high for the foreseeable future. As India and China industrialize, more people in the world are going to be driving more cars in the future, not fewer. Oil production is not going to increase to meet these needs and keep prices low. In time, we will be building a lot of new power plants and making a lot more electric cars. However, this is a 40 year project, not a four year project. GM could perhaps switch all their production to electric cars and light trucks by 2015, but there is absolutely no chance we could build the required 1,000 nuclear reactors in time to power them.
Recently Tesla Motors has announced a pure electric car with a range of 280 miles. Unfortunately, if you plug this car into a standard electric outlet, for example at a motel, overnight you will only pick up enough charge to travel about 50 miles. If you want to drive one of these fantastically beautiful and completely impractical cars across the country, you get to drive 280 miles the first day, and 100 miles per day each day after that: 50 miles in the morning, and another 50 miles in the evening after your eight hour lunch-plus-recharge. It will take you a month to get from New York to Los Angeles. On the plus side, you will have plenty of time on your trip to sight-see, shop, golf.
GM has also announced an electric car, the Chevrolet Volt. Unlike the Tesla, a pure electric car, the Volt also has a small gasoline powered generator and gas tank, which are used to recharge the batteries as you drive. The first 40 miles you drive are on pure batteries; after that you can go roughly 600 miles on the 12 gallon gas tank. Then you refill at any gas station, and you're off for another 600 miles. At night, you plug in and the next morning the first 40 miles are pure electric. You can drive from New York to Los Angeles exactly the same as if you were driving an SUV, except you're getting far better gas mileage and putting only about 20% as much pollution out your tailpipe. When you're commuting at home, you'll most likely need to fill the gas tank a couple times a year. Your $1800 yearly gasoline bill will turn into about a $275 electric bill and $150 gasoline bill.
Here we see the real, workable future of automobiles: an electric car with a gasoline or diesel generator. The generator is only used on long trips. We'll still need to buy oil from overseas, but at a greatly reduced rate. We'll still need to build nuclear reactors, a couple dozen per year most likely, but not 1,000 right now. Our cars will still pollute: on short commuting days, the pollution is moved from our tailpipe to the power plant. On long trips, there is a small amount of pollution coming out our tailpipes, less than even a hybrid. A hybrid has a normal gasoline car engine which is aided by a small electric motor. The gasoline engine has to be able to make reasonable power over the entire speed range of the car. The gasoline generator in the electric car always operates at one speed and is heavily optimized to run at that speed, and therefore is more efficient than the generalist engine in the hybrid.
Dreamers would have us believe we can move over almost immediately to "zero pollution" vehicles, but even these pure electric or hydrogen cars pollute, they simply do it at the power plant instead of on the highway. Since we would need to build roughly 1,000 new power plants, there will be one more or less in your back yard. The real future will be a future of lighter, more efficient cars; of more hybrids; and the phasing in of electric cars with on-board generators. And, eventually, a nuclear reactor in everyone's back yard.
A related topic is alternative fuel sources. Currently we are paying corn farmers huge subsidies to grow corn and convert the corn sugar to alcohol, which is then blended with gasoline. We're also putting huge import duties on Brazilian sugar cane alcohol, which has an enormous price advantage over corn alcohol. This is having a significant negative effect on food prices and inflation, and will have to stop soon. A far better technology, which is being investigated at this time, is to somehow convert cellulose (wood fibers) to sugars, then ferment that to alcohol. Cellulose is basically long chains of sugar molecules bound tightly together. However, it's very difficult to unbind the sugars; few bacteria can do it, and those that can act very slowly. The hope would be that we can develop an enzyme that acts much faster.
The dream cellulose crop would be giant bamboo, a grass that grows to full height in two years and is mature and completely developed in five years. Giant bamboo grows up to 65 feet tall and 4 inches in diameter. This would be an excellent easily renewable alternative bio-fuel source. The only problem is that giant bamboo doesn't grow particularly well in Iowa or Saskatchewan. However, the stalks from corn and wheat crops (both plants are also grasses) would perhaps be just as good.
Alternative bio-fuel sources hold out the promise of increasing supply and reducing costs of oil, and reducing our dependancy on middle east oil. However, these fuels are unlikely to significantly reduce overall pollution - to the contrary, by making gasoline and substitutes less expensive, they will promote faster sales of automobiles in India and China, increasing pollution.
Bio-fuels will eventually work just fine in a Harley or Hayabusa, however, it's difficult to imagine an electric Harley that satisfies the urge to ride a big V-twin. Electric sport-touring bikes would be simply incredible, with no engine noise whatsoever and full torque available at any speed from a dead stop to just under top speed. No clutch required.
What can you do? Dream, consider an electric or hybrid for your next car, and buy stock in Bechtel Nuclear Engineering and General Electric. And watch for press releases from companies working on cellulose enzymes.