Strong oxide electrolyzers (SOECs) are rising to be a sizzling matter on the earth of vitality. They use a strong ceramic materials to separate water into hydrogen and oxygen at extraordinarily excessive temperatures (600°C to 850°C). As a result of excessive working temperature, they’re additionally extremely environment friendly, hitting vitality effectivity ranges between 80-100%. These ranges are considerably greater than different dominant electrolyzers available in the market equivalent to Alkaline (AEL), Proton Alternate Membrane (PEM), and Anion Alternate Membrane (AEM), which normally have effectivity ranges of 58-75%.
Nonetheless, while SOEC effectivity is unparalleled, the excessive prices and technical challenges related to SOECs make them appropriate just for particular, high-value use circumstances.
Notice: LHV 33.3 refers back to the decrease heating worth of hydrogen (33.3 kWh/kg), used to calculate SOEC effectivity by measuring the vitality content material of the hydrogen produced. It represents the usable vitality with out accounting for water vaporization.
The Promise of SOECs
SOECs are distinguished by their excessive effectivity, typically reaching Larger Warmth Worth (HHV) effectivity above 100%. Which means that the vitality output of the method can exceed the vitality enter, a uncommon and precious trait in vitality manufacturing applied sciences. This excessive effectivity leads to the manufacturing of high-purity hydrogen, which is essential for industries that require stringent high quality requirements, such because the artificial fuels sector.
Moreover, SOECs can use waste warmth and steam from industrial processes, making them much more environment friendly and cheaper to run. It is a win for each price financial savings and sustainability in numerous industries.
The place SOECs Actually Shine
- Artificial Fuels: SOECs are significantly appropriate for producing syngas (a mixture of hydrogen and carbon monoxide) for artificial fuels. The excessive purity of hydrogen means much less refining is required, making the entire course of cheaper and extra environment friendly. That is promising for the Sustainable Aviation Gasoline (SAF) trade, which additionally has rising regulatory and manufacturing help. Offtake agreements equivalent to Norsk e-fuels with Sunfire, and Airbus with Genvia, are already in place.
- Steelmaking: The metal trade can lower CO2 emissions by 80-90% utilizing SOECs, as hydrogen can substitute carbon within the iron ore discount course of. The high-temperature setting and the provision of waste warmth in metal crops align effectively with the operational wants of SOECs, additional growing effectivity. Tasks like GrinHy with Sunfire and Salzgitter, and Ceres’ SteelCell growth with Doosan, are key in demonstrating the viability of this use case.
- Nuclear Energy Crops: SOECs might be built-in into nuclear crops to supply hydrogen extra effectively utilizing the surplus warmth from the crops. This not solely boosts plant effectivity but additionally enhances security by decreasing the necessity for exterior hydrogen provides. The mixing of hydrogen manufacturing inside nuclear crops may assist in balancing the vitality grid, offering a versatile and dependable vitality supply. Corporations like FuelCell Power and Bloom Power are exploring this potential.
Company engagement by way of pilot demonstration crops and offtake agreements is essential for scaling up manufacturing from kilowatts (kW) to megawatts (MW). Such initiatives are already underway, indicating a rising curiosity and funding on this know-how.
The Roadblocks
Regardless of their advantages, the promise of SOECs comes at a excessive price—two to a few instances dearer than different electrolyzers. Additionally they face technical challenges because of their excessive working temperatures, which may result in sooner wear-and-tear and better upfront prices. Whereas excessive working temperatures can assist mitigate efficiency loss, in addition they induce thermal stress, growing the danger of stack failure by way of electrolyte cracking or seal breakage. SOECs can run at full load for about 2.5 years, whereas different electrolyzers can final 4-8 instances longer.
Moreover, SOEC know-how depends closely on electrical energy prices as a result of it wants numerous vitality to run the high-temperature electrolysis course of. It’s more cost effective in locations the place electrical energy is reasonable or there may be loads of reasonably priced renewable vitality. However, it struggles in areas with excessive electrical energy prices, unstable energy, or small-scale setups. SOECs want regular excessive temperatures and steady energy to work effectively, so areas with unreliable renewable vitality sources like photo voltaic or wind can have points until they use vitality storage options or good grid administration to clean out the ability provide.
Scaling manufacturing from kW to MW would drastically scale back manufacturing and materials prices and financial savings in complete stack price might be 67% to 77% when evaluating kW to MW scaled applied sciences. Nonetheless, just a few innovators equivalent to Bloom Power and Topsoe have stacks at massive scales, that are important to exhibit technical maturity and long-term viability to traders.
Innovating for the Future
Trying forward, the main focus for SOEC know-how is on technical innovation and price discount. ‘Subsequent-generation’ SOEC know-how goals to deal with the present limitations by enhancing the sturdiness of supplies, optimizing design, and enhancing manufacturing processes. Some examples are:
Manufacturing Innovation:
- Mitsubishi Heavy Industries: Makes use of tubes as an alternative of sheets for stack manufacturing – simplifies gasoline sealing and circulate administration, resulting in improved efficiency reliability
- FuelCell Power: Makes use of disc-shaped stacks to chop prices by repurposing DVD manufacturing equipment; stacks are 95% recyclable
- Elcogen: Automating stack meeting to hurry up manufacturing and decrease prices
Materials and Design Innovation:
- Ceres: Makes use of a Gadolinium-doped ceria electrolyte, which permits for decrease temperature operation, and stack makes use of much less nickel – improves sturdiness and reduces prices
- Elcogen: Operates at a decrease temperature, permitting the usage of cheaper parts equivalent to stainless-steel as an alternative of specialised alloys
- Bloom Power: Slicing out deoxygenation models to simplify system design – reduces prices and upkeep wants
Integration Innovation:
- Topsoe: Integration of electrolyzer know-how with ammonia and methanol manufacturing, leveraging experience by way of their catalyst enterprise
- Sunfire: Crops operating on a mix of alkaline and SOEC electrolyzers, offering a powerful benefit for the power-to-liquid and e-fuels markets
These developments are paving the best way for SOECs to scale up and turn out to be extra reasonably priced. Because the vitality panorama shifts, SOECs may play an important function in a sustainable and environment friendly hydrogen economic system. Nonetheless, realizing this potential will rely upon continued innovation and company partnerships.
