There is great interest in converting electricity overcapacity e.g. from renewables; from fuels such as hydrogen and synthetic gasoline; or for the conversion of nitrogen to ammonia. Solid oxide electrolysis offers a high efficiency route to these conversions utilising technology similar to solid oxide fuel cells. However, there are significant differences between electrolysis and fuel cell operation, and the fundamental aspects of electrolysis have received little attention. This Faraday Discussion brings together the research of leading scientists to address the fundamental aspects of solid oxide electrolysis. Research in this field could yield a new clean chemical industry, potentially allowing greater harvesting of renewables by storing excess energy in a more useful and higher energy density form than electricity.