Renewable hydrogen is increasingly recognized as one of the key decarbonisation options compatible with the EU's climate neutrality goal. We quantify possible cost reductions for renewable hydrogen production until 2050 through electrolysis with off-grid renewable electricity generation systems. We focus on the use of solar PV and on- and offshore wind energy in 30 European countries. We project that towards 2050 hydrogen production costs can fall below 2 €/kg in several countries in Europe. Hybrid configurations, consisting of both onshore wind and solar PV electricity generation, generally result in lower renewable hydrogen production costs. Systems with a relatively high level of full load hours benefit from a reduced share of investment costs for the electrolyser component. The levelized cost of hydrogen produced via solar PV systems can only compete with wind-based systems when significant electrolyser cost reductions are realized, despite the ultimately low expected levelized costs of solar PV-based electricity generation. The novelty of this analysis is that it proffers an overview of the dependencies of the costs of green hydrogen production, and how these costs could decrease over the forthcoming decades across a large set of European countries. Specifically, we show how the dynamics behind the projected renewable hydrogen production costs per country highlight the role that technological learning could have in identifying the most suitable locations for hydrogen production.