How far away are lab-scale nanotechnologies from commercialization? We asked two journalists to investigate.
As a journal with ‘technology’ in the title, we are interested in following the journey of technologies that come out of academic research, or at least the most promising ones. In the applied sciences, we believe it is our mission to promote research that has at least the potential for translation — even though, more often than not, there is a misalignment between the needs of industry and academic preoccupations. We believe it is a valuable exercise for academics, who make up most of our readership, to be acquainted with the struggles encountered by nanoscience-enabled technologies developed in the lab. In the ideal-case scenario, academics should be inspired to provide viable answers to the current bottlenecks. With this aim in mind, we are introducing the Technology Feature article type — short and compelling journalistic investigations about nanotechnologies on their journey towards commercial applications. We aim to publish a few of these every year. In this issue, we look at thermophotovoltaics and water electrolysers.
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Thermophotovoltaics (TPV) refers to a technology that transforms heat into electricity. It works similarly to a photovoltaic cell but is designed for the infrared region. The key component of a TPV cell is the emitter, which absorbs and then re-emits thermal radiation directed towards the photovoltaic component of the cell. A TPV cell can be used to store electricity from intermittent energy sources in the form of heat and then release it. A particularly good emitter is made of carbon (graphite), because it is cheap and can in principle withstand temperatures up to 2,500 ºC. As Dirk Eidemüller writes in his Technology Feature, the premise of this technology lies in the fact that the modules are compact, easily deployable, and do not rely on hard-to-mine materials. Several start-ups are working to scale-up TPV technology. Most efforts currently focus on the robustness of the design and durability of the materials. At the moment, prospective costs range between US$10–75 per kWh for the whole module. Meanwhile, lab-scale devices have been reported that reach heat-to-electricity conversion efficiency up to 40%; with power output orders of magnitude greater than what would be expected from a blackbody emission when the gap between the emitter and the photovoltaic part is just hundreds of nanometres; and with selective emitters that can be engineered to couple with specific photovoltaic modules. If the TPV finds a compelling commercial niche in the near future, then investments will also drive fundamental research to expand the range of applications.
Unlike TPV, proton exchange membrane (PEM) electrolysers are a more commercially mature technology, which however has heavily relied on policy efforts for sustained deployment. Decarbonization plans worldwide consider PEM electrolysers for green hydrogen production, with new green hydrogen projects being continually announced. The green hydrogen project pipeline capacity has now reached 422 GW, closing the gap that the International Energy Agency’s Net Zero Emissions by 2050 Scenario had set for 2030. However, a recent study suggests that this would require a total of US$1.3 trillion in subsidies — far more than the initially projected support (A. Odenweller and F. Ueckerdt Nat. Energy 10, 110–123; 2025). It also found that as of 2023 only 7% of the infrastructure is operational. Most announced projects are still being delayed due to the rising costs and uncertain policies.
In her Technology Feature, Katherine Bourzac interviews various players in green hydrogen technologies and related policies. Economically viable green hydrogen can only come from cheap electricity and cost-efficient electrolysers. The most efficient oxygen evolution reaction electrocatalyst for water splitting is still iridium, which is too scarce for cost-efficient mining. Reducing the amount of iridium or finding non-noble-metal alternatives with a similar efficiency and stability are currently primary research tasks. A lot of research time is spent on the nanoscale understanding of the degradation mechanisms of suitable alternative catalysts for PEM electrolysers. Ultimately, though, green hydrogen will have to compete with grey and blue hydrogen alternatives. The price of grey and blue hydrogen varies by country. In fossil fuel-abundant countries like USA and Norway, and regions like the Middle East, the production costs for fossil fuel-derived hydrogen could be as low as US$1.5 per kg by 2050, even when paired with carbon capture and utilization or storage, as projected by a 2023 McKinsey report ( Perhaps in regions where fossil fuel is less abundant, green hydrogen could be more competitive, but policy support remains essential at this stage.
We hope these Technology Feature articles will become a staple for our readers, as they are for Nature and other Nature Portfolio titles.
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