why arent they practical right now? its far easier to say 'we'll do it when technology is better' than to say 'lets get it done now.' stalling is not a good tactic
We don't have an infrastructure set up to implement those alt energies plus more R and D is needed for them to be feasible. And I believe they will be in twenty years. I'm not saying don't do the research right now. It's ongoing. As soon as the private sector emerges with a reliable, viable product that rivals and is cheaper than oil, I'll be buying it.