The elephant, as always, is "will it scale?"...

It is bacteria. Those usually have no issue scaling.

btw, is there a mindset about centralization efficiency (as in large scale manufacturing) vs small scall distributed ?

If everybody bred these as they see fit, the scale issues might not appear. But I'm surely missing something.

Elephants don't scale up. Sorry about that.

There is more than enough sun falling on the ground in deserts to supply all the energy humans use at ridiculously small conversion efficiencies. It doesn't do us any good because we don't know how to capture that.

No the problem there is actually transporting that. It's no use to build a solar farm there and then stretch a long copper powerline back to wherever it is needed because of the losses involved.

"The studies concluded that the extremely high solar radiation in the deserts of North Africa and the Middle East outweighs the 10–15% transmission losses between the desert regions and Europe. This means that solar thermal power plants in the desert regions are more economical than the same kinds of plants in southern Europe."

https://en.wikipedia.org/wiki/Desertec

I was including transportation issues in capturing. There is also the storage problem.

No storage problem if you build a global superconductor power grid.

Of course that requires superconductors that are reasonably inexpensive and relatively robust and maintainable!

I think it's referring to how efficiently it uses the energy after it is collected by the solar panel. So the collection itself might be <20% efficient, but the synthesis of new materials can be very efficient after that.