[ electrolysis ]
The role of solid oxide electrolyzers in the green hydrogen landscape
In a world grappling with the urgent need to reduce carbon emissions , the future of hydrogen is undeniably bright . As the demand for low-carbon hydrogen continues to grow , we find ourselves on the cusp of a transformative energy shift . According to the two-degree Paris Agreement scenario , the demand for low-carbon hydrogen is projected to reach a staggering 343 million metric tonnes per annum ( Mtpa ). Of this potential demand , green hydrogen is expected to account for 70 %, or roughly 241 Mtpa . Now , compare that to today ’ s reality , where a mere 80 Mtpa is being produced as grey hydrogen worldwide . This means that the green hydrogen market alone is poised to become three times the size of the current grey hydrogen market .
By Sanjay Purswani , Senior Knowledge Analyst , Boston Consulting Group
With such a potential shift in the green hydrogen landscape , electrolyzer market has the potential to reach a staggering ~ 2,000 GW by 2050 . The sheer magnitude of this market potential necessitates a diverse array of electrolyzer technologies to facilitate the global green hydrogen revolution .
Among the multitude of electrolyzer technologies , one particular contender has been catching the eye of industry experts – solid oxide electrolyzers ( SOECs ). This high-temperature electrolysis technology presents some interesting opportunities in integration with heat-intensive applications . Approximately 75 % of the 2050 demand for green hydrogen finds its niche in heat-intensive industrial processes . These heat-intensive applications , such as refining , industrial heat generation , and steel production , can involve on-site hydrogen production and utilization while integrated with SOECs to recover waste heat . In such contexts , solid oxide electrolysis ( SOEC ) emerges as the one of the most promising and viable long-term solution .
At present , the commercial hydrogen electrolysis market primarily relies on two established technologies : alkaline ( AE ) and proton exchange membrane ( PEM ) electrolysis . Both of these technologies operate at relatively low temperatures , differentiating them from SOEC .
SOEC process and materials
SOECs consist of a solid oxide ceramic electrolyte nestled between two porous electrodes . At elevated temperatures , typically between 700 – 900 ° C , the solid oxide electrolyte becomes conductive to oxygen ions ( O 2− ). When an electrical voltage is applied across the electrolyzer , oxygen ions are transferred from the cathode to the anode through the electrolyte , facilitating the conversion of steam into hydrogen gas .
At the cathode , typically made from a perovskite material , oxygen ions and electrons react . The oxygen ions , sourced from the external electrical circuit , combine with electrons to form oxygen gas ( O 2
). Simultaneously , electrons travel through the external circuit from the anode to the cathode , generating an electric current .
16 Hydrogen Tech World | Issue 12 | October 2023