I'm not qualified, but "The technology could serve as a renewable fuel source in high altitude and polar environments" from the first paragraph of the article suggests to me that the potential is pretty limited.
I wonder about the storage though. One would need to produce during summer/polar day for use in winter/polar night - is it feasible to store large quantities of hydrogen for 6 months?
My understanding is that hydrogen likes to leak because its atoms are smaller than the atoms of anything we’d contain it with. Though there are chemical ways to store it and I’m not familiar with those.
I suspect it'd be most practical in areas with limited heat and were other alternatives aren't as handy.
There's also a few areas where combustion engines are more practical than electric ones and hydrogen engines could be used as a stop-gap solution until electric alternatives catch up; there's only so much humanity can do at once and using combustion engines with renewable fuels could reduce emissions while we take our time focusing on other areas.