Green hydrogen and fuel cells will be a very important part of any future energy system, says Switzerland-based energy and sustainability consultancy strategist Dr David Hart. Among the electrolysers that convert renewable electricity into green hydrogen are proton exchange membrane (PEM) electrolysers, with PEM fuel cells then converting the green hydrogen back into green electricity for mobility and stationary power. Both technologies are reliant on platinum group metals (PGMs), which are sourced overwhelmingly from South Africa.