Extending mobility and access to energy for a greater part of humanity while minimizing greenhouse gas emissions is the greatest challenge the earth is facing.
Humanity is in an uphill battle when it comes to preserving the planet to avert some of the worst effects of climate change. As well as satisfying its huge and ever-increasing energy demand.
This equation cannot be solved without an alternative energy solution. It will take a variety of solutions to achieve this goal but one tool that’s gaining traction is hydrogen. Which is produced using a carbon-free process.
Transforming electricity into hydrogen and then using it in the form of gas and fuel or by storing or transforming it back into energy and heat using a fuel cell are the promises of hydrogen power.
Hydrogen is the most abundant element in the universe and it is essential for life. The sun is mostly made of it. And it is present in almost all living things.
So how does this abundant element get turned into a fuel that the planet can benefit from?
Contents
What is hydrogen fuel cell?
Hydrogen (H) is the first element in Mendeleev’s periodic table. It is the simplest and lightest atom which consists of a nucleus containing a proton and a peripheral electron.
Dihydrogen (H2) molecule which is made up of two hydrogen atoms is the subject of chemical exploitation and generates strong interest in energy both in terms of its possibilities of use and storage.
A fuel cell makes it possible to directly convert chemical combustion energy into electrical energy. Itl is an electrochemical device that combines hydrogen and oxygen from the air to generate electrical energy, water and heat through an oxidation-reduction reaction.
How do hydrogen fuel cells generate electricity?
A single fuel cell consists of an electrolyte sandwiched between two electrodes. The oxidizing anode (emitter of electrons) and a reducing cathode (collector of electrons) are separated by an electrolyte.
The electrolyte has the property of conducting ionized molecules directly from one electrode to another and of blocking electrons by forcing them to pass through the external circuit of the battery where the energy can be exploited.
Oxygen from the air passes over one electrode and hydrogen over the other which then produces electricity, water and heat. Bipolar plates on either side of the cell help distribute gases and collect electrical currents.
At the anode, the hydrogen is separated into ions and electrons using platinum or a similar catalyst. The electrons travel through an external circuit generating the required amount of energy.
While the ions pass through the electrolyte to the cathode where with the help of another catalyst they join with the oxygen atoms to produce water.
Let’s apply these explanations to propel a car. The car uses an internal combustion engine fuel by hydrogen. Dihydrogen (H2) explodes into dioxygen (O2), this reaction results in the production of water (H2O) and the release of energy.
The fuel cell produces electricity which powers the electric motor hence propelling the vehicle. These two elements make it possible to obtain motor efficiencies superior to those of conventional motors.
Why Hydrogen fuel cells are gaining importance?
Hydrogen can be converted into electricity, heat, water or motive power depending on the end-use. As an energy carrier of the future and a possible substitute for hydrocarbons, it has several significant advantages:
- Its combustion generates a large amount of energy.
- It is an abundant element on Earth in atomic forms.
- Its combustion produces no CO2 emissions as it comes from renewable sources.
- It can be an effective means of storing electricity over long periods.
- It can power and improve the autonomy of vehicles.
The transport sector offers major development potential for hydrogen fuel. It can be used directly in internal combustion engines or fuel cells.
In some countries, combustion engines using hydrogen are already fitted to buses and waste dumpsters in the form of hythane (mixture of 20% hydrogen and 80% natural gas).
The configuration of heavy or intensive transport gives excellent adaptability to the use of hydrogen fuel cells. The combustion of one kilogram of the element releases three times more energy than that of one kilogram of gasoline.
Hence fuel cell produces more electricity giving the vehicle more power and recharging batteries easily. Speed of recharging is an advantage for truck fleets whose freight patterns do not allow any downtime. Also, fuel cell trucks offer other significant advantages such as gaining autonomy without reducing the payload.
Several countries are at the forefront of applying hydrogen fuel cells in transportation.
- Germany with the H2 Mobility and Callux program
- Japan with the Japanese Large Scale Fuel Cell Demonstration Program
- United States with the US National Hydrogen & Fuel Cell Program
England has committed to reducing its emissions by at least 68% as compared to the 1990 level by 2030 and is thinking to acquire a fleet of hydrogen buses.
The foreseeable increase in the price of traditional fuels associated with the desire of most States to reduce their carbon footprint is likely to stimulate the development of the hydrogen sector in transport.
What are the benefits of hydrogen fuel cells?
An abundant source of energy
From a molecular point of view, H20 is present everywhere on our planet. As a reminder, it is an oxygen atom and two hydrogen atoms (H2O). It is exceptional to note that H2O accounted for more than 90% of the earth.
Clean energy
The International Energy Agency (IEA) assured in a report which dates from 2019 that hydrogen is the energy of the future. Indeed thanks to its low CO2 emissions, this energy seems to be a credible alternative.
Effectively associated with a fuel cell, this energy does not emit CO2. Water is the only release from a fuel cell.
Alternative fuel
Indeed today the majority of transport runs on fossil fuels. One of the biggest contributors to climate change is the transport sector. It represented approximately 21% of overall emissions in 2020.
Transporting goods consumes a lot of energy. One of the solutions envisaged decarbonizing this sector is therefore hydrogen. The combustion of this gas hydrogen engine produces only water, this property makes it a serious candidate as the fuel of the future. We can therefore imagine vehicles that run on hydrogen.
Carbon neutrality
In the fuel cell, hydrogen reacts with oxygen from the ambient air. This reaction results in the production of electrical energy used to operate the vehicle and produces only heat and water.
As the electricity used is produced from renewable energies and does not release toxic gases, the fuel cell is completely carbon neutral.
In addition, vehicles equipped with a fuel cell simply need a small battery for storage which considerably reduces the carbon footprint at the manufacturing stage.
Efficiency
The energy performance of an engine is conditioned in particular by its efficiency. That of vehicles equipped with a fuel cell is about a quarter higher than that of vehicles equipped with an internal combustion engine.
Since hydrogen fuel cells can deliver 3 times more power than gasoline, they deliver more efficiency o the road.
The future of hydrogen fuel cell
Hydrogen has been hailed as a fuel of the future that could help end the world’s dependence on fossil fuels and aid the transition to net-zero emissions.
But for this hydrogen revolution to take place some big obstacles need to be overcome. Currently, hydrogen fuel cells are promising but still require development.
To hope for massive commercialization the cost, performance and compactness of this fuel still need to significantly improve.
Also, the materials currently in use wear out too quickly compared to the expected service life of hydrogen fuel cells. The transport sector is the major prospect for greater use of this fuel.
However, it constitutes a major challenge. Vehicles equipped with hydrogen fuel cells are currently in circulation but they are only a few hundred which are intended to provide feedback to car manufacturers.
Of course, the development of fuel cells for automobiles will not be possible without advancements in the hydrogen sector.
Without development of reliable storage and distribution systems of the gas, the transition won’t be possible. And not to mention that hydrogen is quite hard to manage.
- Hydrogen storage requires large amounts of energy due to its low density.
- The efficiency of its transport is much lower than that of oil or gas due to its low density.
- There are risks of flammability and detonation with air.
- The cost of the most promising hydrogen production process remains high.
- Its use by the general public in transport requires the establishment of a network of hydrogen stations which requires considerable investment.
Hydrogen energy is very promising in more ways than one. Nevertheless, its exploitation on an industrial scale is in its infancy. The question of the dangerousness of hydrogen is frequently asked.
As the dihydrogen molecule is small, the risk of a tank leaking is higher than with traditional fuel. Moreover, the element ignites more easily than gasoline and the resulting flame is barely visible.
However, as hydrogen is very volatile, it disperses much faster in the air than natural gas or gasoline vapors which reduces the risk of explosion.
It has been used for many years in industry where a set of safety standards have been implemented. In the field of transport, research focuses on the materials making up the tanks to avoid the risk of leakage.
Emphasis is also placed on cooling and ventilation systems to avoid hot spots in the engine and reduce the risk of fire. Hydrogen is difficult to transport due to its low energy density per unit volume.
Transport is generally carried out in bottles or pipelines in compressed form. The gas needs to be compressed to 350 bars when stored in tank or 700 bars when transported. It is also possible to liquefy hydrogen at –253°C but this transformation is very energy-intensive. .
Current research is mainly directed towards storage at a lower cost and in a safe manner. In addition to the problems of storage and accessibility, the establishment of a hydrogen distribution network has a significant cost.
A network of service stations distributing the element is needed. For hydrogen vehicles to become more popular, they must be reliable and refueling must be easy to do.
Hydrogen certainly has undeniable qualities but it also has shortcomings. Its development requires heavy investment throughout the production chain.
Whether in terms of production, transportation and storage. It is necessary to succeed in bringing down the costs of fuel cells and even those of electrolyzer.
The Hydrogen Council estimates around 20 – 25 billion euros of investment is needed per year to reach a critical size in 2030. This amount may seem large but it is currently more than 100 times less than the funds allocated to oil investments.
Some studies claim that hydrogen vehicles could be the most efficient, least polluting and least expensive means of transport by 2030.
The projected total investment for pipelines in the hydrogen sector amounts to an estimated $500bn. A lot of venture capitalists are starting to see the potential of the sector.
And scientific advances are moving from laboratories to pilot plants and ultimately getting towards a marketplace. Many nations are also seeing the potential of the industry.
Europe is the leader of green deals which is up to one trillion euros for green initiatives. And some of it is being directed to the hydrogen sector. Germany has announced a €7bn program for the hydrogen industry.
China has a strong target to increase quite dramatically their production of energy plus to move their car fleets from a combustion engine to hydrogen.
In fact, the Chinese government wants to have 1 million fuel-cell-powered vehicles on its roads by 2030 served by 1000 refueling stations. South Korea and Japan carmakers are also very focused on fuel cells and on the automotive market moving to hydrogen.
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