Industry leaders, academics, government officials and non-profit groups are meeting this week at the National Hydrogen Association's 2005 Conference, which runs through April 1. Seventeen hydrogen-powered cars and trucks will be featured at the gathering.

"Of course it is very important to share the latest updated information," said Kazunori Watanabe, a mechanical engineer at Honda. "But it's also very important that it's in Washington, D.C. I hope that this conference helps the government to promote hydrogen policy."

Wednesday Secretary of Energy Samuel Bodman will meet with business leaders at the conference and test-drive hydrogen cars.

According to conference organizers, hydrogen energy promises zero emissions, no dependence on foreign oil, and an unlimited supply of energy.

However, making that dream a reality has proved to be tough, experts note.

"Storage on board the car is very difficult," said Ben Remocker, a mechanical engineer for British company Heatric. "But you can already get a good range on your tank. As the price of energy keeps going up, more energy efficient technologies will compete better. Certainly producing hydrogen is viable."