The material risk of green hydrogen

We expected this to be a piece about how the rising cost of critical minerals was hampering the green hydrogen transition.

But in the two months it took for us to dig deep into the supply chains, the price of cobalt, a critical mineral used for making batteries, electronics, and green hydrogen electrolysers, dropped 35%. Nickel and zinc, two other critical minerals for hydrogen electrolysers, have fallen 30% and 35% year over year. While risks are high in a rising price environment, opportunities abound when prices fall.

Our findings show that hydrogen electrolysers are surprisingly vulnerable to the volatility of critical minerals. But to our surprise, when we talked to green hydrogen developers, few had strategies to mitigate the risks this entailed or capitalise on opportunities when they present themselves.

Critical minerals take centre stage

Hydrogen electrolysers rely on a variety of critical minerals. Each electrolyser technology uses a different mix of metals and varying amounts of particular minerals. Therefore, each electrolyser technology has a different set of upstream risk exposures.

Today’s dominant electrolyser technology, alkaline electrolysis (AE), requires large amounts of relatively common metals like zinc, copper, and nickel. The supply chain risks in those markets are caused by under-investment in bringing new resources online coupled with increasing demand across energy and other technology sectors.

Newer electrolyser technologies focus on delivering operating characteristics that are ideal for green hydrogen production. But to achieve these performance standards, they rely on rarer minerals.

Proton exchange membrane (PEM) electrolysers use small amounts of platinum and iridium, two of the worlds’ rarest and most expensive metals. To put this in perspective, the 1 kg of platinum group metals needed for a MW-scale PEM electrolyser can cost more than the 10 tonnes of minerals and metals needed for a 1 MW onshore wind turbine.

Solid-oxide electrolysis cell (SOEC) electrolysers, on the other hand, rely on the rare earth element yttrium and cobalt. Supply chains for these are highly concentrated in China and the Democratic Republic of Congo, with known human rights and labour violation risks.

Green hydrogen is especially vulnerable to the price of minerals

Ramboll surveyed a basket of energy technologies, including both fossil fuels and renewables, and found that AE electrolysis had the highest share of total capital expenditure (CAPEX) tied to mineral costs.

Green hydrogen is not currently cost-competitive with hydrogen created from fossil fuels. It needs to become less expensive to compete. In the short term, one way to do that is by procuring minerals as cheaply as possible. In the long term, companies will drive down costs by designing systems that use fewer and less expensive minerals. But no matter what, there will be a competition between hydrogen and other energy transition technologies for limited critical resources.

Mineral risks peak during implementation

Like most infrastructure projects, green hydrogen projects progress through four key phases:

From the perspective of an independent green hydrogen developer (not vertically integrated into either power generation or electrolyser supply chains), the exposure to different critical mineral supply chains shifts over time as the project progresses through its major milestones. As such, the risk associated with exposure shifts, as illustrated below.