Very unclear; it says "The device" -- speaking of the catalyst/electrode system that does the electrolysis -- "uses novel, relatively high-voltage solar cells t

Very unclear; it says "The device" -- speaking of the catalyst/electrode system that does the electrolysis -- "uses novel, relatively high-voltage solar cells to generate the needed electricity." Why? If you need a higher voltage, you connect more cells in series. Or, for experimental purposes, you connect to a transformer plugged into the wall. I do not see why the special and apparently short-lived perovskite solar cells are a necessary part of a new type of electrolysis system.