Electrolysers that double up as fuel cells

Electrolysers that double up as fuel cells

Article touches on one of the three virtues of solid oxide technology - the ability to be used to generate power from fuel as well as fuel from power in one single integrated system. Besides fuel cell/electrolyser reversability it offers best in class efficiency and co-gen capability for e-fuels. The model described here for the reversible system exploits the existence of a load following power price to produce hydrogen when power is cheap and work as a power generator in fuel cell mode when its expensive. However there’s another advantage of these integrated systems in that they can be utilised much more of the year than a stand alone Electrolyser would be coupled directly to renewable energy plants for better asset loading.

That said the “killer app” for solid oxide is it’s class leading efficiency not reversability - over 100% if thermal energy from a high temperature power plant or factory can be harnessed and over 80% LHV stand alone. In fact Sunfire recently announced its c150 tpa elecyrolyser system part of Salzgitter (SALCOS) green steel project has achieved 84% LHV.

Looking out to the end of this decade, many believe Electrolyser technology may coalesce around two technologies - a low temperature champion, AEM, which combines some of the best attributes of PEM/ALK including dynamic response, compactness and affordable cell materials and a high temperature champion, Solid Oxide for coupling with sources of high grade heat.

Not surprisingly most of the main SOC players have plans in electrolysis now aswell as fuel cells such as Ceres Bloom Energy Sunfire GmbH, Haldor Topsoe and newcomers Genvia /Elcogen. However the biggest unit demonstrated so far has been less than 1MW so it may be end of decade before it’s vying for market leadership. #fuelcells #hydrogen #energytransition