He said the scientific community predicts that if we do nothing, the planet's climate will be irreversibly changed in 20 to 25 years.

Ovshinsky said hydrogen can be used in place of other fuels.

"Anything that burns can be replaced by hydrogen now," he said.

"If you only have 20 more years to save the planet, you've got to do it now."

And with hydrogen, he said, "There's no war over oil."

Ovshinsky worked on the General Motors EV1 electric car and appeared in the movie, "Who Killed the Electric Car?"

He said current internal-combustion engines in cars and trucks can be converted to run on hydrogen.

With hydrogen, he said, there's no pollution, no climate-change issues.

"All you need for fuel is water," he said "You don't need the Mideast."

Ovshinksy listed various alternative forms of energy - including wind, tides, hydrogen, geothermal and solar energy - and said solar has the greatest potential.

If America dedicated the nation's entire production of corn and soybeans to biofuels, he said, it would meet just 12 percent of the demand for gasoline and 6 percent of the demand for diesel.

He said it will take some time before fuel cell cars are ready for the market, but hydrogen-fueled cars would be practical now if a fuel-delivery system were in place.

When asked if the government should make sure fuel prices remain high in order to encourage development of alternative fuels, he said. "I think it's going to happen naturally."

He said oil supplies will continue to be insufficient and expensive, then added, "You have it in the wrong hands anyway."

Ovshinsky said some government action will be necessary to force movement to more alternative fuels.