I've been following that Joule company for a while.. I'm thinking it's a scam. They get donations through high power... well I'll call them lobbyists. They actually hired Bill Clinton as one of their board members. Last I read they only have 6 patents with over 70 pending, a lot of time to get more funding. They were getting like 35 million a year.
Either way I can't see oil interests NOT buying this up and making it disappear if it isn't complete bs to start out with.
http://www.jouleunlimited.com/why-solar-fuel/overview
Oh, one downside, they need an unlimited supply of Carbon dioxide, they say they can get this from coal fired plants. So you have to pollute the world to make green gas, lol.