Electrolytic Hydrogen A Future Technology Of Energy Storage
Seminar Report on
“ELECTROLYTIC HYDROGEN (A FUTURE
TECHNOLOGY FOR ENERGY STORAGE)”
Submitted to: -
Dr. Babasaheb Ambedkar Technological University, Lonere.
In Partial Fulfillment of The Requirement For
Diploma In Electrical Engineering
Submitted by: -
Deshmukh Adhyay Mahesh (2201218)
Under The Guidance Of: -
DEPARTMENT OF ELECTRICAL ENGINEERING
INSTITUTE OF PETROCHEMICAL ENGINEERING
LONERE 402103, RAIGAD
This is to certify that Deshmukh Adhyay Mahesh (2201218) has completed the project
work entitled Electrolytic Hydrogen (A Future Technology of Energy Storage) under my
supervision, in the partial fulfilment for the award of a Diploma in Electrical Engineering as
prescribed by Dr Babasaheb Ambedkar Technological University, Lonere.
Place: IOPE Lonere-Raigad
Guide: Head of The Department:
First of all, I would like to give my sincere thanks to my guide Prof.U.A.Kharat, who
accepted me as his student & being a mentor for me. He offered me so much advice, patiently
supervised & always guided me the in right direction. I have learned a lot from him & he is
truly a dedicated mentor. His encouragement & help made me confident to fulfil my desire &
overcome every difficulty I encountered.
I would also like to express my gratitude to Dr N.S.Lingayat, H.O.D, Electrical Engineering
Deshmukh Adhyay Mahesh
Electrolytic hydrogen has the potential to be used as a clean, renewable energy source for a
variety of applications, including transportation and electricity generation.
Implementing energy storage with conventional power plants provides a method for load
levelling, peak shaving, and time shifting allowing power quality improvement and reduction
in grid energy management issues, implementing energy storage with RES (Renewable Energy
Source) smooths their intermittency, by storing the surplus in their generation for later use
during their shortfall, thus enabling their high penetration into the electricity grid.
This report introduces hydrogen energy storage technology and its implementation in
conjunction with renewable energy sources. Therefore, energy storage is deemed as one of the
solutions for stabilizing the supply of electricity to maintain the generation-demand balance
and guarantee an uninterrupted supply of energy to users.
In the context of sustainable development and energy resource depletion, the question of the
growth of renewable energy electricity production is highly linked to the ability to propose
new and adapted energy storage solutions.
Sr no. Contents Page no.
1. Introduction 6
Electrolytic Hydrogen- An
What is Electrolytic Hydrogen?
Block Diagram of HESS
What is Hydrolysis?
Why Hydrolysis Method?
Storage of Hydrogen
Basics of Fuel Cell
Comparison Between Hydrogen
and other types of Fuels
7 – 11
Types of Electrolyzers
Solid Oxide Electrolyzer
Polymer Electrolyte Membrane
12 – 14
4. Need of Energy Storage in
Modern Power Systems
15 – 17
Evaluating Pros and Cons of
Electrolytic Hydrogen Production
Position of Electrolytic Hydrogen
Additional Benefits of Hydrogen
in Energy Storage Technology
Limitations of Hydrogen energy
HEST possible economic revenue
streams compared to
18 – 19
Electrolytic hydrogen is a type of hydrogen that is produced through the process of electrolysis.
In this process, electricity is used to split water molecules into hydrogen and oxygen. The
hydrogen produced through electrolysis is considered to be a clean, renewable fuel source, as
it is produced using electricity that can be generated from a variety of sources, including
renewable energy sources like solar and wind power.
Electrolytic hydrogen has several potential uses, including fuel for vehicles, power generation,
and use in chemical processes. It is also being explored as a potential storage medium for
excess electricity generated by renewable energy sources.
There are several benefits to using electrolytic hydrogen as an energy storage technology. One
benefit is that it is a clean and renewable fuel source. Hydrogen produced through electrolysis
does not produce any greenhouse gases when burned, and the electricity used to produce it can
come from a variety of sources, including renewable energy sources. Additionally, hydrogen
has a high energy density, meaning that a large amount of energy can be stored in a relatively
small volume. This makes it an attractive option for energy storage.
ELECTROLYTIC HYDROGEN: AN OVERVIEW
2.1 What is Electrolytic Hydrogen?
Electrolysis is a promising option for carbon-free hydrogen production from renewable and
nuclear resources. Electrolysis is the process of using electricity to split water into
hydrogen and oxygen. This reaction takes place in a unit called an Electrolyzer.
2.2 Block Diagram of HESS (Hydrogen Energy Storage System):
The Electrolyzer (hydrogen generator) is used to convert electrical energy from an energy
source (typically renewable) into hydrogen for storage. The hydrogen storage system can store
the hydrogen in several forms (pressurized gas, metal hydride, or liquid Dewar tank). A
hydrogen energy conversion system then converts the stored chemical energy in the hydrogen
back to electrical energy while giving off water and heat as by-products with no carbon
emissions. The hydrogen energy conversion system that is commonly used is the fuel cell,
given that its typical average electrical conversion efficiency, as recorded for installed projects,
ranges between 40 and 50% compared with a maximum of 37% for a small combustion
engine. Alternatively, the stored hydrogen can be used for other end uses and thus hydrogen
and oxygen gases are sold as commodities.
2.3 What is Hydrolysis?
Hydrolysis is a chemical reaction of the interaction of chemicals with water, leading to
the decomposition of both the substance and water.
H20 - ½ 02 + H2
Conversely, during a time of input energy deficit, this process is reversed and the hydrogen
produced earlier is reconverted to electrical energy through a fuel cell.
Anode Reaction: 2H2 + 20-2 - 2H20 + 4e-
Cathode Reaction: 02 + 4e- - 20-2
Fig1.Process of Hydrolysis
2.4 Why Hydrolysis Method?
• Energy density of H2 is ≥1k times larger than the upper limit of battery storage capacity.
• Hydrogen can be used as a fuel for portable (vehicles) or stationary energy generation.
• void of Carbon emissions.
• Scientist James Barber of Imperial College London hailed this as having "enormous
implications for the future prosperity of humankind."
Energy Density of the following elements:
Storage Method Energy Density (kWh/kg)
Lead-Acid Batteries 0.04
Hydro-storage (per 𝑚3
Flywheel, Steel 0.05
Flywheel, Carbon-Fibre 0.2
Flywheel, Fused Silica 0.9
Compress air (per 𝑚3
2.5 Storage of Hydrogen:
• The hydrogen will be stored in two 0.47 cubic meter (125 gallons) propane tanks and
the oxygen will be stored in one propane tank.
• The produced hydrogen gas is pressurized by the electrolyzer to its maximum rated
• Hydro-electrical power from dams, wind energy and solar energy sources can all be
fitted with hydrogen electrolysis units to produce enough hydrogen.
Hydrogen As Fuel:
• No Greenhouse gases emitted
• Zero emission in vehicles
• Calorific Value is 150KJ/Kg.
2.6 Basics of Fuel Cell:
Fig 2. Fuel-Cell
A fuel cell is composed of an anode, a cathode, and an electrolyte membrane. A fuel cell
works by passing hydrogen through the anode of a fuel cell and oxygen through the cathode.
At the anode side, the hydrogen molecules are split into electrons and protons. The protons
pass through the electrolyte membrane, while the electrons are forced through a circuit,
generating an electric current and excess heat. At the cathode, the protons, electrons, and
oxygen combine to produce water molecules.
2.7 Comparison Between Hydrogen and other types of fuels:
Sr No. Fuel Energy Content
1. Hydrogen 120
2. Ethanol 29.6
3. Liquefied Natural Gas 54.4
4. Methanol 19.7
5. Propane 49.6
6. Coke 27
7. Automotive Gasoline 46.4
8. Wood (Dry) 16.2
9. Automotive Diesel 45.6
10. Bagasse 9.6
The hydrogen atom is the lightest, simplest and most common element in the universe.
However, it occurs only in combination with other elements, primarily with oxygen in the
water and with carbon, nitrogen and oxygen in living materials and fossil fuels. Hydrogen is
not a primary source of energy. However, it becomes an attractive energy carrier when split
from these other elements by using a source of energy. Hydrogen, as a clean energy carrier, is
considered to be the clean fuel of the future, particularly for energy storage and transport. The
energy storage capacity of hydrogen is excellent because calculations show that one kilogram
of hydrogen contains approximately 33 kWh of energy.
TYPES OF ELECTROLYZERS
3.1 Alkaline Electrolyzers:
Alkaline electrolysis as an industrial process has been around since the advent of commercial
power at the beginning of the 20th century with most large-scale plants (up to 165 MW) built
between the 1920s and 1980s in response to hydrogen demand for the ammonia industry. With
the emergence of cheap hydrogen from steam methane reforming in the late 1980s, the
production of small-scale plants (around 1 MW) dominated the electrolysis market. But in
recent years, plant scale has increased (10 MW with few at 100 MW) compared to scale in
the 1990s in response to increased demand for green hydrogen and moving away
from hydrogen production from fossil fuels.
Alkaline electrolyzers operate via the transport of hydroxide ions (OH-
) through the
electrolyte from the cathode to the anode with hydrogen being generated on the cathode
3.2 Solid Oxide Electrolyzer:
Solid oxide fuel cells (SOFC) have been extensively developed as a low-carbon, efficient
electrical power production technology but emerged now also in the use of solid oxide
electrolysis cells (SOEC). Under applied electrical potential a solid oxide electrolyser cell
(SOEC) splits water (H2O) into hydrogen (H2) by transferring oxygen ions (O2-
) through a
solid ionic conductive membrane that after are recombining with electrons to form oxygen
molecules (O2). Based on the electrochemical reaction it is possible to split carbon dioxide
(CO2) into carbon monoxide (CO) or mixtures of water and carbon dioxide (H2O+CO2) to
generate specific synthesis gases (mainly CO and H2) for subsequent processes. Because of
the integration of excess heat into the SOEC process, the efficiency of SOEC systems can be
higher than other electrolysis technologies.
Solid oxide electrolyser cells operate at temperatures between 700 and 1000 °C which enables
nonprecious metals as catalysts.
For reasonable hydrogen production, single cells have to be stacked. To ensure the electric
contacting and gas flow of each cell interconnects and contact elements are used.
Fig4.Solid Oxide Electrolyzer
3.3 Polymer Electrolyte Membrane Electrolyzer:
Polymer electrolyte membrane (PEM) electrolysis is the electrolysis of water in a cell
equipped with a solid polymer electrolyte (SPE) that is responsible for the conduction of
protons, separation of product gases, and electrical insulation of the electrodes. The PEM
electrolyzer was introduced to overcome the issues of the partial load, low current density, and
low-pressure operation currently plaguing the alkaline electrolyzer. It involves a proton-
Electrolysis of water is an important technology for the production of hydrogen to be used as
an energy carrier. With fast dynamic response times, large operational ranges, and high
efficiencies, water electrolysis is a promising technology for energy storage coupled with
renewable energy sources. In terms of sustainability and environmental impact, PEM
electrolysis is considered a promising technique for high purity and efficient hydrogen
production since it emits only oxygen as a by-product without any carbon emissions.
One of the largest advantages of PEM electrolysis is its ability to operate at high current
densities. This can result in reduced operational costs, especially for systems coupled with
very dynamic energy sources such as wind and solar, where sudden spikes in energy input
would otherwise result in uncaptured energy. The polymer electrolyte allows the PEM
electrolyzer to operate with a very thin membrane (~100-200 μm) while still allowing high
pressures, resulting in low ohmic losses, primarily caused by the conduction of protons across
the membrane (0.1 S/cm) and a compressed hydrogen output.
The polymer electrolyte membrane, due to its solid structure, exhibits a low gas crossover rate
resulting in very high product gas purity. Maintaining a high gas purity is important for storage
safety and direct usage in a fuel cell. The safety limits for H2 in O2 are at standard conditions
4 mol-% H2 in O2
An electrolyzer is an electrochemical device to convert electricity and water into hydrogen and
oxygen, these gases can then be used as a means to store energy for later use. This use can
range from electrical grid stabilization from dynamic electrical sources such as wind turbines
and solar cells to localized hydrogen production as a fuel for fuel cell vehicles. The PEM
electrolyzer utilizes a solid polymer electrolyte (SPE) to conduct protons from the anode to
the cathode while insulating the electrodes electrically. Under standard
conditions, the enthalpy required for the decomposition of water is 285.9 kJ/mol. A portion
of the required energy for a sustained electrolysis reaction is supplied by thermal energy and
the remainder is supplied through electrical energy. Its efficiency is about 57- 67%.
Fig5. Polymer Electrolyte Membrane Electrolyzer
NEED OF ENERGY STORAGE IN MODERN POWER SYSTEM
Energy storage increases the power grid capacity in accommodating the increasing
fluctuations in supply and demand, and thus it plays a crucial role in supporting the wider
integration of distributed RES in modern electrical networks. Integrating EST into electrical
networks allows more flexibility in accommodating the increased amounts of RES
In power systems, energy storage provides a method for “Load Levelling” by storing the power
during periods of light loading and delivering it during periods of high demand, thus avoiding
the high costs during peak demand and postponing investments in grid upgrades or in building
new generating capacity. It also provides a method for “peak shaving,” which works like load
levelling but aims to reduce the peak demand. Energy storage can also be used for “time
shifting” by storing the energy during low-price times, and discharging it during high price
times. All these actions allow reduction in the grid’s energy management issues and improve
the power quality. Fig 6 depicts how energy storage allows load levelling and peak shaving
with conventional power plants.
Fig6. Energy storage for Load-levelling and Peak Shaving.
Energy storage is crucial for many applications and while implementing them in large size at
the supply side can assist in the network bulk energy management, implementing them
distributed near the consumer can assist in reducing power quality issues. EST energy storage
duration ranges from few seconds of operation to several hours
Implementing RES into the power generation sector can play a vital role in reducing this
emission percentage and accordingly address the climate change with its associated political,
economic, and environmental pressures. Delivering the RES generation to the load when
needed and to the storage when the generation exceeds consumption allows the absorption of
the excess in RES generation and thus reduces the need for the grid weak interconnections
upgrading and remove a considerable amount of constraint issues. Additionally, implementing
energy storage reduces the spinning reserve requirements and thus allows spinning reserve
operational costs to be diverted to the EST operational costs. The flexibility that the storage
brings to the grid reduces the electrical supply and demand imbalance associated with
increased RES integration, and thus facilitates energy transition.
• Process of Electrolytic Hydrogen and its storage in the modern world:
1. Water molecules (H2O) are split into hydrogen (H2) and oxygen (O2) through a
process called electrolysis.
2. The electrolysis process requires an electrolyzer, which uses a voltage to drive the
3. The electricity needed for the process can come from renewable energy sources such
as solar or wind power, making it a clean and sustainable method for storing energy.
Fig7. Process Of Electrolytic Hydrogen In Modern Power System
4. The hydrogen produced can be stored for later use as a fuel source.
5. When the hydrogen fuel is needed, it can be combusted to produce electricity or used
in fuel cells to generate electricity with high efficiency.
6. Electrolytic hydrogen is considered as one of the most efficient method for energy
storage, as it has high energy density and can be stored for a long time without losing
its energy content.
7. The process of electrolytic hydrogen production is considered as one of the most
sustainable methods as it only produces water as a by-product, making it a
environmentally friendly process.
8. This Hydrogen is further delivered to Commercial and Industrial buildings.
9. The electricity produced from fuel cell can be delivered to grids of same power.
EVALUATING THE PROS AND CONS OF ELECTROLYTIC
5.1 Position of Electrolytic Hydrogen:
Hydrogen is in a strong position to be applied widely as an energy storage vector for balancing
the grid while increasing the RES (Renewable Energy Source) integration. Over the last
decade, several renewable hydrogen concepts have been investigated and several installations
have been implemented to demonstrate the role of energy storage in the form of hydrogen in
balancing the supply and demand in constrained grids.
• Application of Hydrogen Gas:
1. Controllable generation reserve via fuel cells and/or gas turbines and/or internal
combustion engines (ICE).
2. Fuel for transport applications.
3. A means to transfer the renewable energy into the gas grid.
4. A chemical process gas for other end uses in food, fertilizers, etc.
As the governments around the world are strategically moving toward a low carbon economy,
hydrogen storage will undoubtedly play an important role in making use of the grid constrained
“green” energy within a rapidly growing market.
5.2 Additional Benefits of Hydrogen in Energy Storage Technology:
• Injected into the gas grids (since it is mixable with other gases).
• Used to generate electricity and heat via a fuel cell.
• Used to power a fuel cell (FC) or a combustion engine vehicle.
• Used in many industrial processes (like fertilizer production).
• Chemical Feedstock (Production of various chemicals with hydrogen).
5.3 Limitations of Hydrogen Energy Storage Technology:
• Limitations in available modelling software and tools.
• Challenge to quantify the energy capacity.
• High capital cost.
• Low-turn around efficiency.
5.4 HEST possible economic revenue streams compared to conventional EST.
Fig.8 HEST Possible economic revenue streams compared to conventional EST
The Above Figure illustrates; the economic revenue streams of both the conventional and
hydrogen energy storage technologies. While conventional energy storage systems allow for
energy to be stored and released in the form of electrical energy, hydrogen as an energy storage
mechanism allows surplus RES electrical energy to be stored and released as electricity in
addition to hydrogen and oxygen gases that could be sold as commodities offering greater
financial competitiveness. Since this could offset the HEST low energy efficiency and high
capital costs, it is considered in the developed HEST financial competitiveness model.
In conclusion, electrolytic hydrogen is a form of hydrogen produced through the process of
electrolysis, which involves using electricity to split water into hydrogen and oxygen. It is
often referred to as "green hydrogen," as it is produced using renewable energy sources such
as solar or wind power. Electrolytic hydrogen has many potential uses, including as a fuel for
vehicles and as a source of clean energy for various industrial processes. It is considered a
promising technology for reducing greenhouse gas emissions and transitioning to a low-carbon
economy. While there are challenges to its widespread adoption, including the high cost of
production and the need to develop infrastructure, electrolytic hydrogen has the potential to
play a significant role in the transition to a clean energy future.
• HESS: Hydrogen Energy Storage System
• RES: Renewable Energy Source
• ICE: Internal Combustion Engines
• FC: Fuel Cell
• HEST: Hydrogen Energy Storage Technology
• EST: Energy Storage Technology