Advertisement
Explainer | What are electrolysers? How is hydrogen produced and how do fuel cells use the energy?
- In the quest for a greener future, hydrogen is expected to play a key role. Here’s a look at the equipment that releases its potential as an energy source
Reading Time:4 minutes
Why you can trust SCMP
2
Electrolysers and fuel cell systems are the key equipment for the production and use of hydrogen.
Advertisement
More than 95 per cent of hydrogen is currently made using fossil fuels, mainly coal and natural gas, because of their low costs. However, governments’ climate policies and incentives will make the production of green hydrogen, which uses renewable energy, economically viable, presenting big business opportunities.
Here is what you need to know about electrolysers and fuel cell systems.
What are electrolysers and fuel cells?
Electrolysers use electricity to split water into its constituents – hydrogen and oxygen – via electrolysis, which involves chemical reactions and the interchange of electrically charged atoms and ions. The hydrogen produced is considered “green”, or low carbon, if renewable or nuclear power is the energy source.
When the hydrogen is consumed, the process is reversed. In vehicles, the hydrogen is recombined with oxygen to produce electricity, heat and water through a fuel-cell system.
A typical electrolyser uses 9kg of water to make 1kg of hydrogen, with the remaining 8kg released as oxygen. In a standard fuel cell, for every kilogram of hydrogen consumed, 9kg of water is released. A sustainable source of water is a key determinant for siting green hydrogen production projects. Availability of abundant cheap renewable energy is another.
00:47
Green hydrogen: can China reclaim its glory in EVs, batteries and solar panels?
Green hydrogen: can China reclaim its glory in EVs, batteries and solar panels?
Why are electrolysers and fuel cells important for climate mitigation?
Advertisement