None of those can replace coal / nuclear. EDIT: Here's Bill Gates explaining why nuclear is not optional: http://www.youtube.com/watch?v=JaF-fq2Zn7I http://www

None of those can replace coal / nuclear. EDIT: Here's Bill Gates explaining why nuclear is not optional: http://www.youtube.com/watch?v=JaF-fq2Zn7I http://www.youtube.com/watch?v=JaF-fq2Zn7I