Electrolyzer Developments for Building Clean Energy Systems

Electrolyzers are a critical technology for the production of low-emission hydrogen from renewable or nuclear electricity. These systems have been growing in recent years, but at a slow pace. The IEA notes that electrolyzer manufacturing capacity has increased by more than 25% since last year, reaching nearly 11 GW per year. The deployment of all the currently planned projects could lead to a worldwide installed electrolyzer capacity of 170-365 GW by 2030.

However, electrolysis capacity is starting from a low base and requires a significant acceleration to get on track with the IEA Net Zero Emissions by 2050 (NZE) Scenario, which requires installed electrolysis capacity to reach more than 550 GW by 2030. So there is a gap between requirements and what is currently planned.

There are different types of electrolyzers — such as alkaline, proton-exchange membrane (PEM) and solid oxide (known as SOE), as well as some more exotic designs. Each has advantages and disadvantages, and no clear winner technology has emerged yet.

Some interesting projects moving the sector forward:

UK fuel cell pioneer Ceres has announced that its MW-scale electrolyzer demonstrator has produced hydrogen for the first time. Located at partner AVL’s site in Germany, the demonstrator is Ceres’ first real-world foray into hydrogen production. The device is said to now be in the final stages of commissioning, on track to reach factory acceptance testing in the coming weeks. Once signed off, the demonstrator is due to be shipped to Shell’s R&D Center in Bangalore, India.

Based on Ceres’ longstanding fuel cell technology, the solid oxide electrolyzer cell (SOEC) essentially works like a fuel cell in reverse, splitting water into hydrogen and oxygen using electricity. The company has spent the past several years evolving its core SteelCell product to ensure that it can operate in both directions, an advance that saw Ceres win this year’s MacRobert Award, bestowed by the UK’s Royal Academy of Engineering for outstanding engineering innovation. According to Ceres, its SOEC can deliver green hydrogen at <40kWh/kg, which is said to be up to 25 per cent more efficient than existing technologies.

US-based Bloom Energy has installed the world’s largest solid-oxide electrolyzer (SOE) at a NASA research facility in California — and claims that the 4MW unit will produce 20-25% more hydrogen per megawatt than any commercially demonstrated alkaline or PEM equivalent. “Solid oxide electrolyzers offer inherently superior technology and economic advantages,” said Bloom founder and CEO KR Sridhar. The 4MW unit will be able to produce more than 2.4 tonnes of hydrogen a day.

SOEs operate at high temperatures, and when tapping into an external heat source, require less electricity to produce the same amount of hydrogen as equivalent alkaline or PEM electrolyzers, which operate at low temperatures.

Norwegian electrolyzer manufacturer Nel has announced that it will build a long-planned 4GW gigafactory in Michigan, at a cost of up to $400m, to produce electrolyzers for the US and global market. “The choice of Michigan is based on an overall assessment of what the state can offer in terms of financial incentives, access to a highly skilled workforce, and cooperation with universities, research institutions, and strategic partners,” said Nel CEO Håkon Volldal.

As one of the many possible technologies which could enable more energy efficiency and lower emissions, electrolyzers are going to be a part of the transition, although they are currently an emerging technology, the technology itself as well as the market can be expected to mature in the next ten or twenty years.