1. A method for monitoring at least one electrolyser element performance from a group of electrolyser elements, the method comprising: measuring relevant electrolyser element parameters for each of said at least one electrolyser element and storing measurements in a historical database; selecting at least one suitable operation zone for each of said at least one electrolyser element for a curve-fitting analysis; identifying at least one reference element from said group of electrolyser elements, said reference element being a new or well performing element compared to other elements in said group; characterizing each of said at least one electrolyser element by fitting a current-voltage curve using said at least one suitable operation zone and said measurement parameters in said historical database, thereby generating at least one characterization; comparing each of said at least one characterization to said at least one reference element; and determining that each one of said at least one electrolyser element that deviates from said at least one reference element beyond a given threshold is prematurely aging.