Special Focus: Electrolyzer Technologies

R. YU, IMI Critical Engineering, Singapore

Clean hydrogen (H₂) has been a difficult concept to prove, although its potential has been known for a long time. In 1874, novelist and father of science fiction, Jules Verne, claimed water would be the “coal of the future” once its elements could be decomposed by electric current.¹ Despite recognizing H₂ as a powerful energy source capable of widespread use, the prediction has yet to fully materialize nearly 150 yr later.    

Today, sectors that use large amounts of H₂ (e.g., the petrochemical industry) have struggled to progress the cause, despite having a stake in its success. This is a problem because H₂ is a pillar of the energy transition and a key part of the 2015 Paris Agreement. Analysts have warned that H₂ will only make up 5% of the world’s energy mix by 2050, well short of the 15% required to keep rising global temperatures below 2°C.² How can the industry make good on its climate commitments if future fuels are too expensive to produce, difficult to access and still partly dependent on oil, coal or natural gas? 

Promising signs. Polymer electrolyte membrane (PEM) electrolysis—the same process Verne alluded to in his writing—appears to be the best answer to this question. It promises to deliver large volumes of pure H₂ without the carbon penalty if the electricity used is generated with renewables. However, this technology is still relatively new and commercial breakthroughs have, until recently, been slow to reach the market.  

This technique also poses practical challenges, given that many large sites still depend on a grid powered mainly by fossil fuels. This is what makes green H₂ so elusive—it is difficult to produce without significant investment and often impractical for many smaller businesses to consider. Footprint is also at a premium in manufacturing facilities, and production costs continue to rise in many parts of the world, so it is understandable why some might be skeptical of a process still in the early stages of development.  

This situation has created a need for more decentralized technologies that will provide small- to medium-sized businesses a convenient and cost-effective means to produce H₂ onsite. This is a crucial point, as the transition to a greener economy will only be truly effective if the technologies that support it can be adopted at all levels rather than just among larger businesses with deep enough pockets.  

Issues of accessibility. Turnkey solutions are important because they lower the capital expenditures (CAPEX) necessary to make green H₂. While many analysts believe the cost curve is now flattening, many of the requirements needed for production remain unattainable for smaller businesses. According to the International Renewable Energy Agency’s report, green H₂ costs between two and three times more per kilogram (kg) when compared to blue H₂.³ Even if businesses were working against the lower end of that scale, green H₂ would still struggle to make a case in terms of cost-competitiveness.  

Against these numbers, it is not difficult to see why subject matter experts (SMEs) might feel priced out of the market, regardless of their commitment to managing their carbon footprint. Government schemes, including the UK’s recent clean H₂ subsidy, seek to address the issue of cost parity, although many businesses will not be able to secure funding. This is troubling as significant carbon reductions ultimately depend on unimpeded access to the most efficient electrolyzer technology.  

However, even those accepted into a scheme may struggle without the right equipment. Smaller-scale oil and gas refineries will likely be eligible for subsidies, but this may not cover the cost of some PEM electrolyzers, especially if it requires extensive integration with an existing plant. Many large-scale solutions on already on the market—running from 10 megawatts (MW) up to 1 gigawatt (GW)—but these are only suitable for the biggest names across the industry.

Electrolyzers with an integrated skid solution housed in a standard shipping container can be deployed with minimal disruption and at much lower cost. These containers typically offer an optional fuel cell and storage system, eliminating the complications that can arise once H₂ has been extracted—a common stumbling block for organizations without the ability to capture CO₂ when reforming the steam from natural gas. Additionally, digital twin analysis can be used to improve the efficiency of the stack, balance supply and demand, and optimize surrounding equipment, giving smaller organizations access to advanced electrochemical processes and instrumentation without having to gamble on a large or untested investment. 

Looking ahead. Modular designs are still relatively new, but this technology is showing signs that it can be scaled quickly across different markets. The author’s company has been working with several manufacturers, particularly in areas with abundant access to renewable power. For example, one chemical business in Indonesia is keen to take advantage of the geothermal activity found in its local area. Until recently, harnessing this energy for clean H₂ was impractical and expensive. While this example is harder to replicate in regions without as many renewable energy sources nearby, it shows the strategic importance of decentralized production.  

This is key because distribution continues to be debated. Installing 40 GW of electrolyzers, as set out in the European Union’s 2030 roadmap, is an important and ambitious target.⁴ However, most of this capacity will come from centralized hubs and require transportation infrastructure to succeed. Without it, businesses that could have already been generating clean H₂ onsite will be delayed, further delaying the switch from fossil-based practices.  

Applied knowledge of existing systems is now helping to make clean H₂ a reality. PEM electrolysis is an important technique and will be central to the energy transition, but the industry will need better access to the technology—especially leading up to 2030—if it is to have any realistic chance at reducing emissions. Verne’s vision may still be distant, but breakthroughs are moving it from the pages of science fiction and toward reality.H₂T

LITERATURE CITED

¹ V. Ryabchuk, V. Kuznetsov, A. Emeline, Y. Artem’Ev, G. Kataeva, S. Horikoshi, N. Serpone, “Water will be the coal of the future—The untamed dream of Jules Verne for a solar fuel,” PubMed Central, November 29, 2016. 

² DNV, “Hydrogen forecast to 2050,” June 2022, online: https://www.dnv.com/news/hydrogen-at-risk-of-being-the-great-missed-opportunity-of-the-energy-transition-226628 

³ International Renewable Energy Agency, “Green hydrogen cost reduction,” December 2020, online: /-/media/Files/IRENA/Agency/Publication/2020/Dec/IRENA_Green_hydrogen_cost_2020.pdf?rev=4ce868aa69b54674a789f990e85a3f00 

⁴ Hydrogen Europe, “Green hydrogen for a European green deal: A 2x40 GW initiative,” March 2020, online: https://dii-desertenergy.org/wp-content/uploads/2020/04/2020-04-01_Dii_Hydrogen_Studie2020_v13_SP.pdf 

About the author

RICHARD YU works closely with teams at IMI Critical Engineering to drive innovation and develop its H₂ offering. As Director of Business Development – Hydrogen, Yu is committed to developing a more sustainable world by solving the industrial challenges around decarbonization. He earned a BS in textile sciences and engineering and MS in innovation at Singapore Management University.