US aims to drastically reduce costs of hydrogen electrolysers within two years
The agency, which is the Department of Energy’s office for H2 research, development and deployment with a budget of $301m for this year, targets an uninstalled capital cost of $250/kW for PEM electrolysers with an 80,000-hour lifetime and 51kWh/kg energy efficiency by 2026.
The HFTO plans to further drive down costs for the technology to $100/kW, with efficiency reaching 46kWh/kg, between 2029 and 2036.
Based on applications for the $7bn Regional Clean Hydrogen Hubs programme, the current average installed cost for PEM electrolysers sits at around $1,900/kW, with government figures suggesting a $1,000/kW uninstalled capital cost for the equipment.
However, the agency argues that its previous funding for research and development had already slashed the capital cost of PEM systems by more than 90% between the early 2000s to 2020.
More than half of the planned reduction in cost is expected to come from a scale-up in manufacturing. The agency targets 3GW or more of electrolyser manufacturing capacity by 2026, albeit without specifying a split for specific technologies.
Meanwhile, additional cost savings are predicted from innovations in stack and balance-of-plant technology and greater system-integration optimisation — such as reducing the use of expensive platinum group metals (PGMs), which are key catalysts for PEM electrolysers.
While PEM technology currently uses around 0.8 grams of PGMs per kilowatt of capacity, the HFTO aims to slash this to 0.1g/kW by 2026 and ultimately reach 0.03g/kW.
However, the agency notes that while cutting down on PGMs would reduce supply chain costs, it could also lead to worse-performing electrolysers, suggesting a need for trade-offs.
Meanwhile, the US government is even more ambitious when it comes to cost reductions for solid oxide electrolysers (SOEs), which currently cost around $2,500/kW.
By 2026, the HFTO targets $500/kW for these systems, slashing the capital cost down to $200/kW by 2031. While the agency estimates SOE stacks currently have a lifetime of 20,000 hours, it aims to double this by 2026 and ultimately achieve stack lives of 80,000 hours.
Next-generation tech
The HFTO is also exploring novel technologies for producing hydrogen, including:
- Photoelectrocatalysis (PEC), which uses solar power to directly split water into hydrogen and oxygen via photocatalysts;
- Solar thermochemical hydrogen (STCH), based on a solar-powered two-step chemical reaction of metal oxides and steam to produce hydrogen;
- Fermentation and microbial electrolysis, where hydrogen is generated by living organisms either directly or through technologies which pass an electric current through acids generated during decay to produce hydrogen.
While all of these technologies are still at the laboratory-scale, the HFTO plans to fund further research and development over the coming years with the ambition of demonstrating by 2031 the feasibility that all three can produce H2 for less than $2/kg.
Fuel cells
Meanwhile, the HFTO also aims for major improvements in performance and cost for fuel cells this decade, with priority in the short term for PEM fuel cells for use in medium- and heavy-duty vehicles.
As with PEM electrolysers, the biggest cost reduction is expected to come from scaling up manufacturing, with the agency setting a target of 20,000 stacks for heavy vehicles per year by 2030 to drive the cost down from $170/kW to $80/kW.
Meanwhile, fuel cells for stationary power cost between $1,200 and $2,500 per kilowatt of capacity, with an efficiency of 40-60%. The HFTO plans to bring the cost down to $1,000/kW and increase efficiency to 65% by 2030, while ensuring a product lifetime closer to the current maximum of 80,000 hours.
It also aims to develop or demonstrate by 2027:
- A 60%-efficient hydrogen fuel-cell power system (1–10 kW) for back-up power applications at a cost of $1,000/kW with 10,000 hours of durability;
- A 60%-efficient hydrogen fuel-cell power system (at the MW scale) for distributed power/energy storage applications at a cost of $1,000/kW with 40,000 hours of durability;
- A medium-scale combined-heat-and-power fuel-cell power system (100 kW-3MW) that can achieve over 50% electrical efficiency, 90% combined heat and power efficiency and 80,000-hour durability at a cost of $1,500/kW for operation on biogas.
Similarly, the agency has set targets for “reversible fuel cells”, ie, stacks that can be used as either an electrolyser or fuel cell depending on which way the electric current goes, which the HFTO argues could be a promising option for energy storage. However, currently, the round-trip efficiency is only around 37%, with a levelised cost of storage (LCOS) of $1.10/kWh, it says.
As such, the agency aims that by 2030, this technology will achieve a round-trip efficiency of 60% and LCOS of $0.10/kWh.