The first-ever commercially available hydrogen-fuel-cell-powered sedan will be leased to consumers in America and Japan by Honda beginning next month.

The FCX Clarity is a completely new automobile designed from the drawing board to utilize a hydrogen fuel cell engine as its sole power source, according to the company.

The appearance of the new Honda in showrooms in the world’s largest auto market is a clear sign that the automaker anticipates growing consumer interest in fuel cell technology, which combines hydrogen with oxygen to produce electricity and whose only emission is water.

These are the same consumers who have largely embraced hybrid gas-electric engines in the past decade. “The pendulum is definitely swinging,” a spokesman for American Honda Motor Co., Christopher Naughton, said.

The New York City driver wanting to be the first on his block with an FCX Clarity might be in for a bit of a wait, however. Mr. Naughton said the company expects the majority of the new fleet will be leased in Southern California, the only area of the country with enough hydrogen refueling stations to allow widespread daily use of the car. The company will review all lease requests for the car on a case-by-case basis, he said.

Manhattan devotees of fuel cell technology are resting their hopes on a special Shell station in White Plains, the closest hydrogen refueling spot to the city. The FCX Clarity has a driving range of some 280 miles on a full tank of liquid hydrogen and gets a combined fuel economy of 74 miles a gallon “GEE,” or gasoline gallon equivalents, a term used by the Environmental Protection Agency to rate alternative fuel engines.

Honda plans to offer three-year lease arrangements on 200 FCX Clarity models beginning next month. The $600-a-month lease will include collision insurance and maintenance. The company’s original fuel cell vehicle traced its roots to an electric-battery-powered prototype re-fitted with fuel cell power packs. The car was primarily used in state and federal government fleets, including two cars in Albany.

For now, California is the center of the alternative fuel universe. Three Honda dealerships in the California cities of Costa Mesa and Santa Monica now comprise the world’s first fuel cell automobile dealer network, according to the company. Among the first FCX Clarity customers is the actress Jamie Lee Curtis, who lives in Santa Monica with her husband, the actor Christopher Guest.

It’s only a matter of time until there’s enough demand in the Northeast for liquid hydrogen stations, Mr. Naughton said. “This is a private sector initiative on the part of Honda,” he said.

American automakers are currently staging hydrogen fuel cell test programs, but none offers such a car for sale in dealerships. The Big Three received funding to develop hydrogen-based fuel cell vehicles after President Bush announced a $1.2 billion fuel cell initiative at his 2003 State of the Union Address.

Part of the federal initiative was to develop a national infrastructure to produce, store, and distribute the amounts of liquid hydrogen needed to power the widespread use of fuel cell engines. A resident scholar with the American Enterprise Institute, Kenneth Green, said one of the drawbacks of fuel cell technology is that it is only as good as the availability of hydrogen.

Because most of the world’s hydrogen is produced from coal power, the use of fossil fuels and the added costs of processing make the overall environmental promise of fuel cells doubtful, he said. “This is just ‘green’ showboating for Honda,” Mr. Green said, calling the FCX Clarity “a toy for 200 wealthy environmentalists.”

“There’s just no infrastructure to produce the amounts they’d need beyond a fleet of 200 cars,” he said.

There are 14 hydrogen refueling stations in all of America, the Department of Energy’s deputy press secretary, Jennifer Scoggins, said. One of the locations is part of a Shell station on Benning Road in Washington, D.C., which has a 1,500-gallon, double-vault underground tank to supply hydrogen to the 77 fuel cell vehicles driven by Department of Energy employees.

Part of the Department of Energy’s $1.2 billion initiative announced by President Bush in 2003 resulted in General Motors’ “Project Driveway” test program, where drivers in the New York, Los Angeles, and Washington, D.C., metropolitan areas were loaned the Chevrolet Equinox fuel-cell-powered vehicle.

A Shell station in Westchester County equipped with a gaseous hydrogen storage tank supplies the cars in the New York portion of General Motors’ Chevy Equinox test program. A Shell spokeswoman said it isn’t a retail station but a special fueling depot created in partnership with the city of White Plains.

According to Shell, the owner of any properly registered fuel cell vehicle can stop and buy hydrogen in White Plains so long as the driver has completed a safety course at the depot. So if New Yorkers are able to lease the new Honda FCX Clarity next month, they’ll be visiting the Shell depot in White Plains whenever they need to refuel.

Hydrogen currently costs about $5 a gallon. But proponents of the fuel say that it’s three times more efficient as gasoline.

Until now, a commitment to alternative fuel meant trading exterior styling for environmentally friendly technology under the hood. That’s why one of the more remarkable aspects of the CFX Clarity is that it’s a surprisingly sleek four-door sedan.

It shares its platform with Honda’s flagship, the Accord. Even though it’s three inches shorter from bumper to bumper, its comfortable 110-inch wheelbase is the same.

The American Enterprise Institute’s Mr. Green said American interest in alternative fuels will wane if gasoline prices return to last year’s levels. “There’s compelling evidence that oil will eventually fall back to the $60-a-barrel range,” he said. “It’s a bubble; it’s not a matter of scarcity. People won’t switch from gas to hydrogen or anything else unless they really have to.”

Added Mr. Green: “My money’s still on gas. Hey, the gas-powered Hondas get great mileage. Why bother with hydrogen-powered Hondas?”