This is an excellent article and quite an optimistic project. I'll add a couple comments/questions.

Too bad no one has gotten algae bio-oil to work. The infrastructure to store, transport and consume it is in place and the cellulose could be disposed in such a way as to sequester that carbon. Apparently, separation of the oil from the algae is the problem. The other advantage of that is there would be far less need for mineral extraction for batteries.

... Crystals are a low energy level of an atom. Too bad we can't easilyconvert CO2 to diamonds and oxygen.