Another reader weighs in regarding this post:
. . . the point of separating hydrogen out of water is NOT so that it can be recombined. It is so that the chemical energy stored in the hydrogen can be used to produce heat and/or electricity. Up to this point, the special metals required to create electrolysis in large quantities were very cost prohibitive and therefore this breakthrough is like finding out you can drill for gasoline directly with a straw and a spoon instead of a costly oil rig and refinery. It’s about getting to the energy. And the use of a solar cell is a novel idea that in the long run makes the system non-reliant on outside energy sources to produce the hydrogen. Not blindingly new, but novel and intuitively smart.
On the other side of the coin, the use of hydrogen to power fuel cells has been around for a while, but it suffers from it’s own shortcomings and many people are working on that problem is well. So now that we can (probably) get hydrogen cheaply, then the next step will be to effectively store and use it wherever and whenever we want. Imagine your only physical connection to the outside world being a water pipe coming to your house. You trap gray water (runoff from showers and sinks) supplemented with fresh water and use the water to produce hydrogen thanks to a small PV cell on your roof. The hydrogen is used to power a fuel cell in your house that produces all the electricity you need. And if you are REALLY feeling independent you have your own private well run off the fuel cell to bring water to the surface which you turn to energy.
All of this is a little far out in the future, but the concept is sound and the research you spotlighted is the kind of work it will take to move toward that day.