Hydrogen was thrust into the spotlight as a promising clean energy source by President George W. Bush in his 2003 State of the Union address. President Bush touted the potential for a “hydrogen economy” that would greatly slow the release of carbon dioxide into the atmosphere. Since then, billions of dollars have been invested in an attempt to realize this vision.
Hydrogen’s appeal is obvious. When hydrogen is combusted in an engine or consumed in a fuel cell, it combines with oxygen to form water. Thus, a car running on hydrogen is primarily emitting water vapor as a waste product.