In the first decade of this new century, clean energy technologies are transforming the way we power our homes, our businesses, and our vehicles. Before the decade is out, I believe we will see even more dramatic breakthroughs.

This isn't just my opinion as U.S. secretary of energy: Clean energy is gaining momentum in the global marketplace as well.

Venture capitalists are investing hundreds of millions of dollars in alternative energy technologies. The Ardour Global Index of renewable energy companies began operating in May 2006. The investment community clearly believes money can be made in renewable energy, which is just another sign that renewable energy is on the verge of a major market expansion.

In short, the case for "green" energy is as strong as it has ever been.

President Bush's Advanced Energy Initiative seeks additional funding for clean energy technologies, beginning with a 22 percent increase in 2007. The United States is accelerating its research into technologies that we believe hold the greatest promise to be competitive in the marketplace.

Clean energy systems are incredibly diverse, yet technology has brought them within our grasp. Cellulosic ethanol, hydrogen fuel cells, next-generation nuclear power, photovoltaic solar cells, and near-zero-emissions coal plants will transform the way the economies of the world are powered to more clean, alternative sources of energy.

As the various articles in this journal explain, these new technologies promise to raise standards of living around the world and are giving us the tools to build a brighter, cleaner, and more prosperous future. I hope you will find these essays to be as interesting and informative as I have.

Samuel W. Bodman

U.S. Secretary of Energy