Chinese companies spent 10 years aggressively maneuvering to become the dominant players in solar power. Now they’re seeking to lead the way in developing the next big thing in clean energy: hydrogen.

Top solar manufacturers including Longi Green Energy Technology Co. are ramping up the production of electrolyzers, the equipment needed to make green hydrogen, the cleanest form of the fuel. They are accelerating investments on a bet that a market will boom as industries and consumers switch to lower-carbon fuels.