Hydrogen can be produced through the electrolysis of water, which involves using electricity to split water into hydrogen and oxygen. This process allows hydrogen to be generated using renewable energy sources like solar and wind, making it a sustainable and eco-friendly fuel option. The document discusses the principles, types, costs and challenges of water electrolysis, examining alkaline electrolyzers, PEM electrolyzers and high-temperature electrolyzers. It also outlines applications of hydrogen in transportation, energy storage, and industry, as well as ongoing challenges like improving the efficiency and reducing the costs of electrolysis and developing better storage and transportation methods for hydrogen.

1. Hydrogen Production
from Water Electrolysis
Hydrogen has the potential to become a significant alternative fuel source.
This presentation provides in-depth knowledge about the principles, types,
cost, and challenges of hydrogen production through water electrolysis.
KW by Kin Wai Cheah

2. The Basics of Hydrogen Production
Water: the Fuel
The concept of hydrogen production from
water has been around for decades.
Through electrolysis, hydrogen and
oxygen can be separated from water
molecules.
Renewable Energy Sources
The production of hydrogen from water
can be achieved from any energy source,
such as wind or solar. This makes it an
eco-friendly and sustainable option.
Fuel Cells
Hydrogen obtained through water
electrolysis is used as fuel in fuel cells,
which generate electricity. Fuel cells have
numerous applications, such as in
vehicles and homes.

3. The Science of Water Electrolysis
1 Chemical Reaction
Water is dissociated into hydrogen
and oxygen through an
electrochemical process, driven by
a power source, such as
electricity.
2 Electrolyte
A substance, such as sodium
hydroxide, is added to water to
increase its electrical conductivity.
The electrolyte is an essential part
of the water electrolysis process.
3 Catalysts
Catalysts such as platinum are
added to the electrodes to speed
up the reaction. A good catalyst
can increase the efficiency of the
process.

4. Types of Electrolyzers
Alkaline Electrolyzers
One of the oldest types of
electrolyzers, they use a liquid
electrolyte, such as potassium
hydroxide, and are suitable for large-
scale hydrogen production.
PEM Electrolyzers
They use a solid polymer electrolyte
such as Nafion, and are suitable for
small-scale hydrogen production.
They require a lower temperature
and pressure to operate.
High-Temperature
Electrolyzers
They operate at higher temperatures,
between 700-1000°C, using solid-
state electrolytes such as doped-
ceramics. They are suitable for high-
temperature heat and steam
production as well as hydrogen
production.

5. Advantages and Disadvantages of Water
Electrolysis
Advantages ✅
• Eco-friendly and sustainable
• Can be powered by renewable energy sources
• No carbon emissions
Disadvantages ❌
• The process is energy-intensive
• High capital and maintenance costs
• Scaling up for commercial use is challenging

6. Cost Analysis of Hydrogen Production
Alkaline
Electrolyzers
PEM
Electrolyzers
Investment Cost Low High
Operational Cost Low High
Efficiency 70% 80%
The cost of hydrogen production via water electrolysis has been decreasing rapidly. The cost of renewable energy sources has a
significant impact on the cost of hydrogen produced.

7. Applications of Hydrogen Produced by Electrolysis
1
Transportation
Hydrogen fuel cells can power vehicles such as cars, trucks,
trains, and buses. They emit only water, and provide a
2
Energy Storage
The use of hydrogen as a form of energy storage is an
alternative to traditional batteries. It can store excess
renewable energy from solar and wind sources and provide
grid stability.
3
Industry
Hydrogen can replace fossil fuels in various industrial
applications such as refining, chemical production, and

8. Challenges and Future Prospects
Renewable Energy Sources
The availability of cheap renewable
energy is crucial to reduce the cost of
hydrogen production through water
electrolysis.
Energy Efficiency
Improvements in the efficiency of the
electrolysis process can reduce energy
consumption, and therefore the cost of the
hydrogen produced.
Storage and Transportation
Hydrogen has a low volumetric energy
density, which poses a challenge for its
storage and transportation. Innovations
are being developed to overcome this
challenge.