China’s largest electrolyser maker has unveiled a new alkaline model that is more efficient than most Western machines, once again raising questions over whether Chinese manufacturers will be able to corner the market in the coming years.

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Longi Hydrogen — which currently has 1.5GW of electrolyser manufacturing capacity and will have 2.5GW by the end of this year, according to research house BloombergNEF — has unveiled a new alkaline electrolyser model called ALK Hi1 Plus, which it claims can split water molecules into hydrogen and oxygen with extraordinary efficiency, producing one normal cubic metre (Nm3) of H2 with just 4kWh of electricity. (Nm3 is a common measurement representing one cubic metre of unpressurised gas at 0°C)

BNEF said last year that Chinese-made alkaline electrolysers were up to 75% cheaper to buy than their Western counterparts and just as efficient, prompting concerns about the future of the European electrolyser manufacturing sector.

Longi’s new electrolyser would put it among the most efficient alkaline machines in the world.

By way of comparison, the table below shows comparable efficiencies of alkaline electrolysers made by some of Europe’s largest manufacturers (figures taken from an electrolyser intelligence report produced by the World Hydrogen Leaders conference organisers in December 2021). Efficiency rates can go up or down depending on the amount of power — and current density — being utilised by the electrolyser at any given time.


Electrolyser model



Efficiency (vs H2 HHV)

Longi (China)

ALK Hi1 Plus

4.0 - 4.1

44.5 - 45.6

Up to 88.5%

Nel (Norway)


3.8 - 4.4

42.3 - 49.0

Up to 93.2%

John Cockerill (Belgium)


4.16 - 4.66

46.3 – 51.8

Up to 85.1%

McPhy (France)

All models



Up to 78.7%

Sunfire (Germany)




Up to 75.3%

The figures above show that Longi’s new ALK Hi1 Plus machines could produce 15% more hydrogen per kWh of electricity than Sunfire’s rival machine — which is significant because the cost of power makes up the lion’s share of the levelised cost of hydrogen (LCOH).

Other types of electrolyser, such as PEM or AEM tend to be less efficient. The aforementioned study showed Plug Power’s GenFuel 4MW PEM machine as having a power requirement of 5.2kWh/Nm3; with Nel’s M5000 PEM electrolyser needing 4.53kWh/Nm3, and Enapter’s AEM EL 2.1 machine requiring 4.8kWh/Nm3.

Of course, efficiency alone does not determine the LCOH, with other factors such as electrolyser and balance-of-plant capital costs and running costs, the number of hours per year the system is in operation, reliability, operations and maintenance all contributing to the LCOH.

Longi says that with its new electrolyser: “For [every] 0.1kwh/Nm3 reduction in hydrogen production, DC [direct current] power consumption, depending on the number of system utilisation hours, hydrogen LCOH can be reduced by 1.8-2.2%, which is equivalent to a reduction of the initial investment of hydrogen production equipment by 10% to 25%.”

So does this mean that Western electrolyser manufacturers should be worried?

Well, they already are. BNEF warned last year that the European electrolyser manufacturing sector could face a similar collapse to the one seen in the solar industry in the 2010s, when cheaper Chinese modules flooded the market.

Last month, 21 European hydrogen companies, including 11 electrolyser makers such as Nel, Sunfire and McPhy, called upon politicians to introduce “Made in Europe” requirements for EU hydrogen subsidies in order to protect the domestic manufacturing sector against cheaper Chinese imports.

Independent clean-tech consultant and H2 expert Gniewomir Flis tells Hydrogen Insight that the new Longi machines show that “Chinese electrolyser manufacturers are catching up technologically to European competitors”.

“In order to fend off this challenge, European manufacturers should consolidate and pool resources to rapidly scale up innovation,” he says.

“Incumbent producers and conglomerates often have the manufacturing know how, but their technology is far from best in class. Meanwhile, the newcomers have exceptional tech, but little experience of mass manufacturing.”

Longi, however, has plenty of experience in mass manufacturing. Its parent company, Longi Green Energy Technology owns Longi Solar — the world’s largest integrated solar module maker — which recently announced plans to build the planet’s biggest solar factory, at a cost of $6.7bn.