February 1, 2007 4:00 AM PST
FAQ: Guide to alternative fuels
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5. Hybrid cars
What: Toyota scored big with the Prius, which runs on an electric motor and a gas motor: in the city, it mostly runs on electric, but switches to gas on the freeway. General Motors wants to cut the use of gas further with its Volt. In the Volt, which could be ready in two or three years, the gas motor doesn't run the car. Instead, it exists to recharge the battery. In the end that leads to less fuel consumption. Ford, meanwhile, is touting the Edge, an SUV in which a hydrogen fuel cell recharges the battery. The battery in the Edge also gets charged by plugging into a wall.
Similarly, several small companies have touted plug-in hybrids. These are similar to the Prius, but the battery for running the electric motor can be recharged through a plug.
Pros: The less the gas motor gets used, the greater the gas mileage and the lower levels of greenhouse gas emissions. Ford has also minimized the tasks for the hydrogen fuel cell so you won't have to worry about refilling it too much, especially if you charge the battery.
Cons: None that are too big. The public clearly likes hybrids. Still, Toyota has been the big success story here. It is unclear how well GM and Ford will do. Also, questions remain on whether the public really will buy hybrid SUVs and sedans. SUV customers tend to look at features beyond fuel efficiency, but the data isn't conclusive yet.
6. Electric cars
What: Better batteries are allowing car manufacturers to run cars wholly on electricity. Tesla Motors, Think Global and Wrightspeed are marketing all-electric sports cars and economy cars. Zap says it will do a mid-size sedan. Some companies are selling electric scooters and rickshaws into India.
Pros: The more a vehicle runs on electricity, generally the less pollution it creates. An all-electric car produces no tailpipe emissions. Emissions are created indirectly because the power plants that charge the batteries in these cars often run on coal. But in most cases, you see a big reduction in greenhouse emissions. Battery makers like Altair Nanotechnologies and Valence Technology hope to score big.
The mileage is fairly astounding; it only costs a few cents per mile to run an electric car. Tesla and Wrightspeed have also shown that electrics can hang with Ferraris and Porsches.
Cons: The range. Most of these cars can only go 100 to 200 miles before they need a recharge, although Zap says its car will go 350 miles. Forget conspiracy theories: earlier electric cars died out because they didn't get very far and had ornate charging procedures, say execs at Toyota, and even electric car advocates. Batteries also cost a lot of money. Building an all-electric car like a Honda Accord today would probably cost you $20,000 or more in batteries, says Ian Wright, founder of Wrightspeed. Progress is occurring and sales are growing, but it will take time to improve the battery technology.
7. Gas to Fuel
What: Shell and ExxonMobil are ramping up production of a fuel in Qatar called Gas-to-Liquids that's derived from natural gas. It significantly reduces the sulfur, carbon monoxide and other pollutants that belch from car tailpipes. And although more costly than regular gas, it should help crimp the air pollution in places like Los Angeles, or in New Delhi, where diesel buses are banned. GTL is made through a variation of the Fischer-Tropsch process invented nearly a century ago for turning coal into gas. (Irwin Rommel, the German field marshal in World War II, drove across North Africa on coal turned to liquid).
Pros: Instead of starting with coal, the GTL process begins with synthetic gas created in an industrial plant. The synthetic gas derives from natural gas--which is far cleaner than coal--and other materials. You can actually drink it. Food producers use a kosher-approved GTL derivative used to line juice boxes. It goes straight into diesel buses and cars. It's on sale in select stations in Europe and Asia.
Cons: It's expensive. A gallon of GTL takes an inordinate amount of natural gas. The oil companies are mostly only making GTL out of oil fields that are too expensive or difficult to connect to pipelines. While GTL is already being sold in select stations in Europe, it will mostly pop up in polluted megacities.
8. Compressed Natural Gas
What: A barbeque on wheels. CNG cars and buses run on methane, which pollutes less than regular gas. They've been around for years and can be seen at the airport all the time. Researchers at the University of Bath, however, are working on sportier models.
Pros: They've been around for years. Hence, there aren't technological problems to work out. The world's supply of natural gas is also fairly good. CNG taxis and buses are popular in places like Dubai because the oil fields are close by, according to Richard Steele, CEO of AFV Solutions, which makes CNG and hybrid-diesel buses.
China is eyeing more CNG cars, according to Barbara Finamore, director of the National Resources Defense Council's China Clean Energy Program. They want to clean up for the Beijing Olympics and "biofuels are not a good bet here" because crops can compete with food, she said.
Cons: Natural gas isn't renewable and, even though it's cleaner than regular gas, it's still a fossil fuel.
What: For years, hydrogen was widely considered to be the fuel of the future. In hydrogen fuel cell cars, hydrogen and oxygen are mixed in a fuel cell. The resulting chemical reaction produces electrons, which power a battery in the car, and water vapor. There is no pollution created in the reaction. Toyota and Ford have talked about bringing out hydrogen cars in 2015 or 2020.
Pros: It will be nearly impossible to run out of hydrogen in the universe. The prototype cars have also continued to improve. Some hydrogen prototypes can run at over 100 miles per gallon. Engineers are also figuring out ways to store the compressed gas so hydrogen cars can still have a trunk.
Cons: Although the car doesn't belch pollution, making hydrogen typically produces large amounts of carbon dioxide at the factory. To make hydrogen, most producers combine methane with water and heat up the mix to 815 degrees Celsius, which produces 9.3 kilograms of carbon dioxide for every kilogram of hydrogen. Hydrogen is also expensive to make, store and transport. You can't send it down regular pipelines. Then there is that problem of building hydrogen filling stations.
Competitors aren't scared.
"Hydrogen is hopeless," said Martin Eberhard, CEO of Tesla.
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