SEATTLE -- Alaska Airlines began an expensive trial of biofuel-powered passenger flights Wednesday, billing the 75 trips as a pioneering effort to "fly cleaner" and to kick-start a nascent renewable-energy economy.
Travelers on the first two flights -- to Washington, D.C., and to Portland, Ore. -- received a flier titled "Welcome to Greener Skies" as their plane took off from Seattle-Tacoma International Airport, powered by a blend of regular jet fuel and 20 percent biofuel made from used cooking oil.
It's part of a worldwide push by airlines to address claims that plane emissions contribute to global warming. United Airlines flew the first biofuel-powered passenger flight in the U.S. on Monday from Houston to Chicago.
Never mind that burning biofuels produces as much carbon emissions as regular jet fuel. It's counted as "greener" because the carbon dioxide emitted is from renewable sources or, as in this case, from waste byproducts that would be produced anyway.
Yet the fledgling industry is far from proving its economic viability.
Alaska paid $476,000 for 28,000 gallons of biofuel to power the flights over the next 11 days. At $17 per gallon, that's six times what it pays for regular jet fuel.
For the airline industry, the appeal of biofuels -- produced from oily "feedstocks" including camelina oil, jatropha seeds, algae, used cooking oil or animal fats -- is driven by relentless pressure from environmentalists.
Though aviation contributes only an estimated 2 percent to 3 percent of the world's carbon-dioxide emissions, that's likely to grow as air travel rapidly expands in the developing world.
Biofuels were certified as safe jet fuel only in July, making it possible to fly passengers in biofueled planes.