By itself, understanding the natural process won’t enable an instant solar fix. Attempts have been made to create synthetic cubanes but the water splitting ability is a millionth of that of the natural system. PSII, like all enzymatic processes, is orders of magnitude more efficient that simple inorganic catalysis.
But that efficient ways of mimicking photosystem II will now be discovered seems inevitable. The goal is to create from air, water and sunlight liquid fuels and feedstocks such as methanol that will not only power motor vehicles (allowing all the existing infrastructure of pipelines and filling stations to remain) but allow the chemicals and plastics industries to be fed from a carbon-neutral source. In some cases these processes will even be carbon negative in taking carbon dioxide (to be reduced by solar-generated hydrogen) from power station effluent or even the air.
Watch that cubane space!
Science, 15 August 2014, pp. 736 and 804-808