Hydrogen

In an interview with MIT Technology Review, Secretary Chu made what has become known as the “Four Miracles” comment—essentially that issues with fuel cell durability and cost; hydrogen production; hydrogen storage; and hydrogen distribution infrastructure all required significant development, resulting in “four miracles” that needed to occur before hydrogen fuel cell vehicles would be viable in transportation. This assessment was the basis for his decision to apply the funding in that area elsewhere.

A response to the four miracles speech

http://www.greencarcongress.com/2009/06/nichols-20090619/comments/page/2/