Direct production of highly pressurised hydrogen from electrolytic water splitting can allow saving relevant amounts of energy compared to down-stream gas compression. The aim of this project is to develop a novel polymer electrolyte membrane (PEM) electrolyser able to produce hydrogen at very high pressure (200 bar) thus reducing the post-compression energy consumption. Another goal is to develop a cost-effective technology allowing to achieve large-scale application of PEM electrolysers. A significant reduction of capital costs is achieved by critical raw materials minimisation, developing cheap coated bipolar plates and operating the electrolyser at a high production rate while assuring high efficiency (about 80% vs. HHV) and safe operation. ADVANCEPEM aims at developing a set of breakthrough solutions at materials, stack and system levels to increase hydrogen pressure to 200 bar and current density to 5 A cm-2 for the base load, while keeping the nominal energy consumption <50 kWh/kg H2. Reinforced Aquivion® polymer membranes with enhanced conductivity, high glass transition temperature and increased crystallinity, able to withstand high differential pressures, are developed for this application. The approach is to operate the innovative membrane at high temperature 90-120 °C under high pressure to allow increasing energy efficiency. To mitigate hydrogen permeation to the anode and related safety issues, efficient recombination catalysts are integrated both in the membrane and anode structure. The new technology is validated by demonstrating a high-pressure electrolyser of 50 kW nominal capacity with a production rate of about 24 kg H2/day in an industrial environment. The project will deliver a techno-economic analysis to assess reduction of the electrolyser CAPEX and OPEX. The consortium comprises an electrolyser manufacturer, membrane and catalyst supplier, an MEA developer and an end-user for demonstrating the system.