Current status of hydrogen production by water electrolysis market segments
1. Classification of China's technical routes for hydrogen production by electrolysis of water
The basic principle of hydrogen production by electrolysis of water is to dissociate water molecules into hydrogen
and oxygen through an electrochemical process under the action of direct current, and precipitate them at the
cathode and anode respectively. According to the differences in technology and structural principles, it can be
divided into alkaline water electrolysis (ALK), proton exchange membrane pure water electrolysis (PEM), anion
exchange membrane water electrolysis (AEM), solid oxide water electrolysis (SOEC) and other schemes. The
reaction temperature of the first three is about 70-90 degrees Celsius, and SOEC needs to react at a high
temperature of 700-800 degrees Celsius.
2. Comparison of technical routes for hydrogen production by electrolysis of water
From the technical indicators of each electrolysis technology, high-temperature solid oxide (SOEC) electrolysis has
the highest electrolysis efficiency but the shortest life; traditional alkaline (ALK) electrolysis has the most
advantages in life and cost. At present, the practically applicable water electrolysis hydrogen production
technologies are mainly ALK and PEM technologies. SOEC electrolysis and AEM electrolysis are still in the early
demonstration and research and development stages respectively.
From the perspective of the bidding projects of water electrolysis hydrogen production equipment of various
technical routes, the bidding volume of alkaline technology route electrolyzers in 2023 will dominate, with a bidding
scale of 2846.5MW, accounting for 95.7%, PEM technology route electrolyzer bidding scale of 66MW, accounting
for 2.2%, and SOEC bidding scale of 63MW, accounting for 2.1%.
3. Current status of the water electrolysis hydrogen production market segment
- Traditional alkaline (ALK) electrolysis hydrogen production
Traditional alkaline (ALK) electrolysis hydrogen production is currently the most widely used electrolysis hydrogen
production technology. At present, demonstration projects with a scale of more than tens of megawatts are mainly
based on renewable energy power generation plus alkaline liquid electrolyzers.
In terms of product application, the four mainstream alkaline electrolyzer companies are all involved in power,
metallurgy, chemical industry and other application fields. From the perspective of customer distribution, in addition
to the Chinese market, each company's alkaline electrolyzer also has broad space in the overseas market, and
domestic alkaline electrolyzer products are also highly competitive internationally.
——Proton exchange membrane (PEM) electrolysis hydrogen production
my country's PEM electrolysis hydrogen production technology is in the product development stage. Many
domestic institutions have carried out research on PEM technology, and PEM electrolyzers have been
mass-produced. PEM water electrolysis hydrogen production has the highest purity. Under the background of dual
carbon, PEM water electrolysis hydrogen production may have more advantages.
According to the "China Hydrogen Energy and Fuel Cell Industry Handbook (2020)", the localization rate of PEM
water electrolysis hydrogen production equipment is about 80%, which is lower than the localization rate of alkaline
water electrolysis hydrogen production equipment (95%). Its core component electrolyzer has not yet been fully
localized, especially the proton exchange membrane relies on imports.
At present, proton exchange membrane electrolyzers are still in the early stages of commercial promotion, but from
the capacity design of related companies, it can be seen that all companies are optimistic about the large-scale
application of PEM electrolyzers in the next few years. Most of the capacity plans around 2025 are at the 500MW
or GW level.