There will only be a few hundred, and they won't be cheap, but Toyota is about to take

its first small step into the unproven market for emissions-free, hydrogen-powered vehicles.

The world's largest automaker announced Tuesday that it will begin selling fuel cell cars

in Japan on Dec. 15 and in the U.S. and Europe in mid-2015. The sporty-looking, four-door

Toyota Mirai will retail for 6.7 million yen ($57,600) before taxes. Toyota Motor Corp

hopes to sell 400 in Japan and 300 in the rest of the world in the first year.

Fuel cell vehicles run on compressed hydrogen gas, which in the Mirai's case is stored in

two tanks mounted underneath the vehicle. They emit no exhaust, though fossil fuels

are used in the production of hydrogen and to pressurize it. Both Honda and Hyundai are

also experimenting with limited sales and leases of fuel cell cars.

Besides the relatively high cost, buyers will have to contend with finding fuel. Only a

few dozen hydrogen filling stations have been built worldwide, though governments are subsidizing

the construction of more.

It's an uncertain future that depends both on whether makers can bring down the price,

and a wide-enough network of filling stations is built. Yoshikazu Tanaka, deputy chief engineer

for Toyota's next generation vehicle development, said he expects it will take 10-20 years for

the Mirai to reach sales in the tens of thousands of vehicles a year.

Asked if it's a risk, he said yes, but Toyota views it as a challenge. Likening it to a

chicken and egg situation, he said if you say it's too risky and don't move forward

with production, the number of filling stations will never grow. Toyota faced a similar scenario

with its gasoline-electric hybrid, the Prius, which now sells in big numbers.

"It was a big challenge when we first introduced the Prius, or hybrid car, in 1997," he said

in an interview in Tokyo. "And it's an even bigger challenge this time because there is

no infrastructure, and we're trying to lead" the commercialization of fuel cell cars.

Hoping to offset the inconvenience of finding fuel, Toyota gave the car a futuristic look

inside and out � Mirai means future in Japanese � and made it peppy to try to attract buyers.

It accelerates particularly quickly from about 40 to 70 kilometers (25 to 45 miles) per hour,

Tanaka said.

The Japanese government also plans to offer a 2 million yen subsidy to purchasers of fuel

cell cars, reducing the effective price to 4.7 million yen.

Sales will be limited to the primarily urban areas that have fueling stations.

In Japan, with about 30 stations, that means the regions around Tokyo, Osaka and Nagoya

cities in central and western Japan and the northern part of Kyushu island in the south.

A few stations have opened in California in the United States, and there are plans to

build some in the Northeast. Germany and the United Kingdom are among European countries

that have or plan to build them.

The first buyers are expected to be affluent people who want to reduce their carbon footprint

and governments and companies that want to go green.

The Mirai can travel 650 to 700 kilometers (400-435 miles) on its two tanks of hydrogen.

Hydrogen may be more expensive than gas initially, because there are so few customers but, over

time, Toyota expects it will be cheaper to run a car on hydrogen than with gas.