Water electrolysers (WEs), as a type of flexible demand, can offer a variety of electrical grid services provided that such trials are both technically and economically feasible. This report, serving as the first deliverable of QualyGridS aims at identifying the technical feasibility of using WEs for electrical grid services by using a survey-based approach. The surveys are conducted from the grid service perspective and the WEs perspective respectively, in order to derive preliminary matchmaking between the technical requirements of grid services and the technical abilities of the WEs.