I think $2.50 would do it. The problem with this technology is it costs $35/bbl, while the middle east can produce for $4 (yes, they ARE raping us right now). I'm sure Shell's reluctant to pursue this because they could be drowned in Saudi oil at cheap prices at any time.
We need to find a way to stabilize prices and supply, then drain middle east oil until it's scarce enough that it costs them $35/bbl.
I'd go for invading the middle east, taking their oil, and putting their population on food stamps and required birth control. If the left is going to accuse us of such a thing, we may as well really do it.
Shell is a big oil company....it doesn't look like it wants to stymie this process. I do find it interesting how-ever that Shell is "floating" this proposal in the MSM just as oil prices are reaching a huge high....you don't suppose there's anything disingenuous about this now do you?