Power to hydrogen through polygeneration systems based on solid oxide cell systems

This study presents the design and analysis of a novel plant based on reversible solid oxide cells driven by wind turbines and integrated with district heating, absorption chillers and water distillation. The main goal is produce hydrogen from excess electricity generated by the wind turbines. The proposed design recovers the waste heat to generate cooling, freshwater and heating.

The different plant designs proposed here make it possible to alter the production depending on the demand. Further, the study uses solar energy to generate steam and regulate the heat production for the district heating. The study shows that the plant is able to produce hydrogen at a rate of about 2200 kg/day and the hydrogen production efficiency of the plant reaches about 39%.

The total plant efficiency (energy efficiency) will be close to 47% when heat, cool and freshwater are accounted for. Neglecting the heat input through solar energy to the system, then hydrogen production efficiency will be about 74% and the total plant efficiency will be about 100%. In addition, the study analyses the plant performance versus wind velocity in terms of heating, cooling and freshwater generation.