For the sustainable development of the renewable hydrogen sector, alkaline electrolysis appears to be a technology of choice. Nevertheless, despite its long history that showed its reliability in the industrial field and despite the traditional belief from the scientific community, alkaline electrolyzer technology still requires optimization to meet the new challenges imposed by the deployment of large electrolysis plants, notably in the case of future massive islanded renewable hydrogen production plants. In fact, it turns out to be critical to reduce capital expenses (CAPEXs) costs, improve energy efficiency over time, and improve the dynamic response to intermittent power sources to lower operating expenses (OPEXs) costs while operating safely. In this context, some very fundamental challenges related to electrode degradation, electrolyte and bubble transport, membrane optimization, etc., must be addressed right now before being transferred to GW-scale industrial projects that should be commissioned in 2030.