Is This A Good Idea : Science Channel

May 24, 2011

Unless you've been hiding inside a walled compound in Pakistan, you've probably noticed that gasoline is getting pretty costly again. (To see just how expensive it is to fill your tank in various parts of the U.S, check this unsettling Department of Energy chart.) To some people, the only answer is to look for more oil to drill and refine into petroleum. The problem with that approach is that there's a finite amount of oil under the Earth's surface, and many experts say we've already reached the point of so-called peak oil, where the rate of production will rise no higher and instead is beginning to dip into a terminal decline as we steadily exhaust oil deposits. Here's a sobering 2010 presentation by former BP chief petroleum engineer Jeremy Gilbert on that possibility. Even if you don't agree with him, it's inevitable that eventually we're going to have that day of reckoning. And besides the ruinously rising price of fuel, cars and trucks powered by petroleum contribute about two-thirds of the climate-altering greenhouse gases emitted by the U.S. transportation sector, according to this U.S. Environmental Protection Agency breakdown.

The reason that petroleum is so problematic for us is that we're still wedded to the gasoline-powered internal combustion engine, a technology for propelling vehicles that won out over competing models in the 1920s, a time when global oil reserves probably seemed boundlessly plentiful. Improvements such as laser spark plugs and Fiat's MultiAir system, which eliminates direct mechanical linkage to the air intake valves and makes combustion more efficient, may well extend the life of the gasoline-powered automobile engine. But still, over the long run, the gasoline-powered engine is headed for extinction.

But what will take gasoline's place? Biofuel? Plug-in electric cars, charged with electricity generated from wind or solar planels? Hydrogen fuel cells? Natural gas? All those have been offered as possibilities, and each one has its pluses and minuses. But there's another, albeit unlikely, prospect: What about a steam-powered external combustion car, which would use only a small amount of gasoline or biofuel to boil water to drive the wheels? At least in theory, such a vehicle could be both efficient and much cleaner than a conventional car.

Steam, you say? You're probably thinking that I'm on some bizarre non-electronic, neo-Victorian alternative reality sort of kick. And indeed, I do admit to installing the Steampunk theme in my Google Chrome browser.

But steam-powered vehicles are actually an old concept. In 1770, a French engineer named Nicolas-Joseph Cugnot built and demonstrated the first self-propelled vehicle, the Fardier. The horseless wooden three-wheeled cart was powered by pressurized steam that was released by a rotary valve to push pistons in the vehicle's two cylinders. The Fardier, now in the Tampa Bay Automobile Museum, has been restored, and actually still runs, as you can see in this video.

Steam technology continued to develop through the 19th century, and Leon Serpollet's invention of the smaller-scale flash steam boiler in the 1880s led many early automobile makers to opt for steam propulsion. This 1898 New York Times article on the emergence of the automobile quotes a European professor named Czischek who predicted that steam, rather than electricity or gasoline, would emerge as the dominant means of propelling the new vehicles. He pointed out that steam engines ran at a slower rate of revolutions per minute and required less reduction to match the rate at which the wheels turned, making them easier to handle. By the early 1900s, 124 different manufacturers were making steam-powered cars, and in 1906, a Stanley Steamer set a world automotive speed record of 127.6 miles per hour. "Stream is reliable and easily understood," one early manufacturer claimed. Here's a period Stanley brochure that explains how its steam car worked.

But steam cars were soon relegated to the technological junkyard. They needed a kerosene burner under the water tank to bring it to a boil, and that made smoke. The tank itself, which reached an internal temperature of 500-plus degrees F, gave off residual heat that made drivers and passengers sweat. They required frequent refilling of the water supply. Because it took time to build up heat to roll, they were notoriously slow to accelerate. They tended to be bulky, if not ungainly, because of the boiler. And as this 1906 article from The Motor Car Journal notes, the affluent class who bought most of the early automobiles in the pre-mass production age saw the newer, sleeker gasoline-powered cars as more avant-garde fashionable.

But in the decades that followed, a handful of visionaries and tinkerers continued to believe that steam was better. Here's a recent New York Times article about Robert Paxton McCulloch, who tried in the 1940s and 1950s to develop a steam-powered automobile called the Paxton Phoenix. After the 1973 global oil crisis, the Swedish automaker Saab developed an innovative nine-cylinder axial steam-car design that used electronic controls to improve efficiency and reduce the size and weight of the boiler, and added a compressed-air pump to speed up acceleration. The car used only miniscule amounts of fuel to heat the boiler and generated almost no greenhouse gas emissions. But after the oil market stabilized in the 1980s, the Saab steamer never got off the drawing board. In the 1990s, German researchers came up with a low-emissions engine design, the ZEE, that used ceramic cylinder linings instead of oil as a lubricant. Here's a 2001 New Scientist article touting the technology and a press release in which it was promoted as "cleaner than the air we breathe." But again, the idea never made it to market.

But now another outfit, Florida-based Cyclone Power Technologies, has developed the Cyclone Mark V Engine, a high-efficiency engine with a burner that is designed to utilize whatever fuel source is available, from propane gas to orange peels and fryer grease. It also has fewer moving parts and components than conventional car engines, which reduces the weight and, at least in theory, makes it more reliable. Here's a recent TV news story on the company. According to this SmartPlanet.com article, defense contractor Raytheon recently placed a $400,000 order with Cyclone for engines based upon the Mark V design for military applications. But Cyclone's dream is to have a car maker put its engine in a production automobile. From the company, here's a visual comparison of its engine to a conventional gasoline-powered internal combustion engine.