Stack design for a Megawatt scale PEM electrolyser
The main objective of MEGASTACK is to develop a cost efficient stack design for MW sized PEM electrolysers and to construct and demonstrate a prototype of this stack. The prototype will demonstrate a capability to produce hydrogen with an efficiency of at least 75% (LHV) at a current density of 1.2 Acm-2 with a stack cost below €2,500/Nm3h-1 and a target lifetime in excess of 40,000 hours (< 15 μVh-1 voltage increase at constant load).
In the project we aim to take advantage of the existing PEM electrolyser stack designs of ITM power as well as novel solutions in the low-cost stack design concepts developed and further refined in the FCH-JU projects NEXPEL and NOVEL. In order to successfully up-scale the design concept from a 10-50 kW to a MW-sized stack, we will in the MEGASTACK project perform integrated two-phase flow and structural mechanics modelling together with optimization of stack components such as MEAs, current collectors and sealings which are important for stack scale up. The development activities will focus on existing solutions, already proven in kW-sized electrolyser stacks, rather than aiming to use completely new, unproven concepts and materials. The stack design will have ease of manufacture and stack assembly as a major goal, with necessary quality control processes and robust supply chains for components.
To reach these ambitious objectives, MEGASTACK will develop and demonstrate an enhanced stack design essential for cost-competitive, efficient and dynamic PEM electrolysis systems through the following key concepts:
Clearly, the development of a large scale stack for PEM electrolysers is not a trivial endeavour. It is highly unlikely that a simple scale up of an existing stack design would be successful. It is thus necessary to take an integrated approach, involving a multidisciplinary team with expert knowledge of all aspects related to stack construction and operation, such as: