Steven Chu: I think, well, among some people it hasnâ(TM)t really shifted. I think there was great enthusiasm in some quarters, but I always was somewhat skeptical of it because, right now, the way we get hydrogen primarily is from reforming [natural] gas. Thatâ(TM)s not an ideal source of hydrogen. Youâ(TM)re giving away some of the energy content of natural gas, which is a very valuable fuel. So thatâ(TM)s one problem. The other problem is, if itâ(TM)s for transportation, we donâ(TM)t have a good storage mechanism yet. Compressed hydrogen is the best mechanism [but it requires] a large volume. We havenâ(TM)t figured out how to store it with high density. What else? The fuel cells arenâ(TM)t there yet, and the distribution infrastructure isnâ(TM)t there yet. So you have four things that have to happen all at once. And so it always looked like it was going to be [a technology for] the distant future. In order to get significant deployment, you need four significant technological breakthroughs. That makes it unlikely.
â¦ If you need four miracles, thatâ(TM)s unlikely: saints only need three miracles.