When wind turbines produce more power than we can manage to consume, the excess electricity can be used to produce CO2-neutral synthetic fuels by electrolysis. A new collaboration between DynElectro and DTU Energy will develop and test a new control method for high-temperature electrolysis cell systems that can reduce production costs and extend the life of the plants.


Project info

Innovation project ’AC:DC
Mar – Dec 2019
120,000 DKK under ’Teknologisamarbejde i Region Sjælland’
“DTU Risø Reaktor”
Case no. RFS-17-0012

In the project solid oxide electrolysis cells (SOECs) were tested with a new operation method called AC:DC. The operation method decrease the degradation rate for SOECs. In the graph below AC:DC operation was used on SOEC cells from DTU Energy to conduct steam electrolysis. With AC:DC operation the cell resistance was constant after a 50 hour  initiation period. In contrast, for conventional operation, the resistance increase with time.

AC:DC operation was also conducted with CO2 electrolysis for 600 hours. Here AC:DC operation was shown to reduce the degradation rate from 39 mΩcm2 per 1,000 hour to 5 mΩcm2 per 1,000 hour and to increase the impurity tolerance.

Microscopy data suggests the stable resistance with AC:DC operation is related to a removal of Nickel migration, which limits the lifetime of conventional operated SOECs.

The AC:DC operation method is patented by DynElectro ApS. Further info about the AC:DC operation method can be found in the published patent application.