We investigate optimal technology choices for providing H2 at German fuel stations. This includes decentral electrolysers at the stations, as well as central electrolysis plus transport in gaseous or liquid form, or via liquid organic hydrogen carriers (LOHC). In doing so, we explicitly take power system repercussions into account. These differ between technologies because of different flexibility characteristics. We find a trade-off between energy efficiency and power system flexibility, which plays out differently at varying levels of renewable penetration and H2 demand.