Europe is committed to developing alternative forms of renewable energy to reduce dependence on fossil fuels and address major global environmental and climate challenges. The European Strategic Energy Technology Plan (SET-Plan) has identified fuel cells and hydrogen as among the important areas that can contribute to meeting energy and climate goals. A large consortium of highly qualified partners initiated the EU-funded project 'Advanced electrolyser for hydrogen production with renewable energy sources' (ADEL) to develop cost-effective hydrogen production technology based on renewable resources. Fuel cells operating in reverse mode produce hydrogen from the electrolysis of water molecules. Current state of the art uses solid-oxide electrolysers (SOEs) for high-temperature steam electrolysis (HTSE). The ADEL concept is centred on intermediate-temperature steam electrolysis (ITSE) that promises to increase electrolyser lifetime while maintaining performance and energy efficiency of the system. During the first project phase, scientists fabricated single cells, single repeat units (SRUs) and short stacks of cells based on SOE materials to investigate intermediate-temperature (down to 700 degrees Celsius) operation. Preliminary results demonstrate good performance, consistent durability and promising transient operation for all three. Scientists modelled behaviour of an SOE stack at both 800 (HTSE) and 700 (ITSE) degrees Celsius and compared both energy performance and return-on-investment. Although ITSE require more heat input for operation, it offers some advantages in terms of unit electricity consumption and investment cost. Simulation tools have been chosen and validated to assess appropriate energy sources (nuclear, solar, wind and biomass) and integration of ITSE into a hydrogen power plant. Performance of the ITSE device has been analysed and the layout optimised. ITSE is a technically feasible way to generate hydrogen and contribute to a sustainable energy programme. As with other emerging fuel cell technologies, exploitation of SOEs requires significant cost reductions. ADEL expects to deliver a 50 kW demonstrator incorporating the best technology available today.