This is from my local newspaper: Bouncing gas prices may be squeezing monthly budgets, but energy experts say a sustained rise in fuel prices could translate to healthier air as drivers look at options that are cheaper, cleaner and renewable. High gas prices have also led to a cottage industry of mechanics who are converting engines that use fossil fuel into ones that use electricity and kitchen oil. "If you look back to the 1970s, market forces certainly have a way of changing people's behavior," said George Douglas, a spokesman for the U.S. Department of Energy's National Renewable Energy Laboratory in Golden, Colo. "If gas prices rise enough, people start driving more fuel-efficient cars; they drive their cars less or they use vehicles that have fewer fossil fuels in them. Those all reduce the amount of carbon in the air, and that's a positive." Gas prices have more than doubled in the past five years — from a national average of $1.52 a gallon for regular in 2000, to $3.07 after Hurricane Katrina disrupted national supplies this year. That rise has resulted in the following trends, according to Douglas and others. • Hybrid car sales are on the rise nationally. Waiting lists grow as new models are introduced. • Metro-North Railroad saw a short-term spike in train use in the Lower Hudson Valley when gas prices peaked in late summer and early fall. Car pools also became more popular. • Tinkerers are starting to benefit from converting vehicles into ones that don't rely on gasoline. Take George Westphal, for example. The retired mechanical engineer from Pearl River drives a 1985 Nissan Sentra he converted to electric power about six years ago as a personal challenge. Now, he pays about 3 cents a mile to get around, about a third to a quarter of what most drivers pay to power their gasoline vehicles. "When the engine went, the cost of the repair would have been more than the car was worth," said Westphal, who started his working life as an auto mechanic. "It's basically a (train) station car now because you can only go about 25 miles without recharging the batteries, but lately it's paying for itself." Using a manufacturer's kit, Westphal replaced the car's fuel tank with batteries, the engine with an electric motor and relay switches, and implanted his recharging plug where he used to insert the gas pump nozzle. Now his license plate reads "GOINOHM," and he's got a 120-volt system, powered by 650 pounds of batteries, that is big enough to push a much heavier car. Since gas prices started moving up, Westphal finds he is using the car more. "I like driving an electric vehicle. When the body on this finally goes, I'll go to a small pickup truck," he said. "They're the easiest to convert." One thing Westphal doesn't need to worry about is exhaust fumes — they disappeared for good when he pulled out the Sentra's exhaust system. "I did this for myself, to see if I could, more than for any other reason," the 66-year-old grandfather said. "But not polluting the air makes me feel good." That's a benefit as far as Wally Little is concerned, too. The Yorktown resident runs Wally's Super Service, an auto repair shop in Mahopac, and likes spreading the gospel of cleaner air every time one of his customers looks to find a way to keep down his or her fuel costs. Little has been busy, as gas prices have risen, converting cars and trucks from diesel fuel to vegetable oil fuel. They need a little diesel fuel to help warm the engine; otherwise, they are just as powerful as vehicles that use soot-producing fuels. Little got started in the diesel-conversion business after Jonathan Pratt, a friend and neighbor, showed off a Ford 250 pickup he was running on used kitchen oil generated by the three restaurants he owns. "I guess all my buddies sat back and waited until I had about 20,000 miles on my truck," said Pratt, who owns Peter Pratt's Inn in Yorktown and the Umami cafes in Croton-on-Hudson and Fishkill. "Then they all bought Ford 250s, and now everyone is out gathering vegetable oil." Initially, it was like looking for petroleum in a sheik's backyard. Restaurants, who have to pay to get rid of the oil properly, were happy to give it away for free. "Imagine in one neighborhood, four vehicles running on renewable fuel," Pratt said. "There are hardly any emissions because 97 percent of the emissions are absorbed by nature and turned back into oxygen. " Pratt said he had been spending $800 a month in diesel fuel to drive back and forth to three locations, at 10 miles to the gallon. With his fuel now coming from his kitchens, that cost has all but disappeared. David Friedman, research director for clean vehicles at the Union of Concerned Scientists, said if gas prices stay high, the move away from fossil fuels could occur faster than the 50-year horizon some are predicting. "The history of biofuels is that when the government is interested in a new technology, it moves forward," Friedman said. "When it isn't, progress wanes." Friedman said the emerging energy technologies — hydrogen, batteries, ethanol — will have to be made more economical to work in most applications and will have to be produced in a clean manner to deliver the environmental help the scientific community promises. "We know what petroleum's characteristics are," he said. "We don't know as much about the others. For all of this, we need a vision like the one that got us to the moon. The irony is, it's a lot easier. The first step is auto mechanics, not rocket science."