A decade ago, China dominated solar manufacturing with low prices, eliminating Western rivals. The US and Europe are determined not to let the same happen to hydrogen. It is possible to extract hydrogen from water without producing any planet-warming emissions. This is a crucial step towards creating green fuels that could decarbonise industries such as steel, cement or shipping. Electrolyzers use electrical energy to split water into hydrogen and oxygen.

The European Union has set a target of producing 10 million tonnes of green hydrogen per year by 2030. But it has yet to decide which methods qualify as "green". Analysts expect Chinese electrolyzers to become more efficient, undermining the technological advantage of European companies.