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Did you know, the UK is the second most active country in hydrogen and fuel cell research in Europe? But what exactly is hydrogen fuel cell technology, how does it work and how does it compare to conventional methods of power generation?
What is hydrogen fuel cell technology?
Hydrogen fuel cells provide zero emission power at point of use. The hydrogen used in the electrochemical reaction can be extracted from various sources including water, methanol, ammonia, or derived from natural gas.
Renewable hydrogen gas, produced via electrolysis (green) or using carbon-capture (blue), is the optimal type of fuel for use in fuel cells as zero emissions are produced in generation and use.
There are though different types of fuel cell technologies using other fuels, such as natural gas or methanol. As such hydrogen is considered a versatile energy carrier, according to the International Energy Agency. PEM is one of the types of hydrogen fuel cell technologies available. Others, including AFC, PAFC, MCFC and SOFC, also exist, which you can learn more about in our guide to the different types here. The difference between them lying within the electrolytes used in the reaction, their operating temperatures and the type and extent of emissions generated.
History of hydrogen fuel cell technology development
Did you know, the first fuel cell was invented in 1839 by Sir William Grove? Hydrogen fuel cell technology as we know it today was then developed in 1939 by Francis Bacon and was further developed by Pratt and Whitney in the 1960s, eventually being utilised by NASA for in-flight power, heat, and drinking water.
How do hydrogen fuel cells work?
Hydrogen fuel cells work via an electrochemical reaction, where stored hydrogen and oxygen from the air combine to generate electricity, heat, and water vapour.
There are two electrodes within the hydrogen fuel cell: a negative anode and a positive cathode. A reaction takes place at both of these electrodes with the help of an electrolyte and a catalyst. This reaction generates electricity.
Below is a step-by-step summary of how hydrogen fuel cell technology works:
- Hydrogen atoms enter at the negative anode. Oxygen is fed to the positive cathode.
- Hydrogen atoms are separated into protons and electrons by a catalyst at the anode.
- The protons are positively charged and they then pass through the electrode (also known as the membrane) over to the cathode. The electrons are negatively charged and can’t pass through the membrane, so are forced through a circuit which generates electricity.
- The electrons and protons meet at the cathode to reform hydrogen. This then combines with oxygen to produce heat and water vapour as by-products (no greenhouse gases or pollutant emissions are released).
Top 5 advantages of hydrogen fuel cell technology
There are many benefits to utilising hydrogen fuel cell technology over traditional combustion methods of generating power. Below are some of the top advantages to the technology:
- Low to zero emissions. Hydrogen fuel cell technology produces electricity, heat, and water vapour as by-products, presenting an alternative to fossil-fuel based emissions that are released by traditional combustion engines.
- Modular. The great thing about hydrogen fuel cell technology is that it’s both modular and scalable. Multiple hydrogen fuel cell modules can be connected together in a single system meaning they can be easily scaled to achieve the desired power output.
- High efficiency. Did you know a hydrogen fuel cell can be more than twice as efficient as an internal combustion engine? Combustion typically has an efficiency of 33-35%, whereas fuel cells can be up to 60% when it comes to generating electricity. The reason for this is because conventional engines burn fuel to create heat, which is then converted into mechanical energy, and finally into electricity. Fuel cells involve fewer steps and therefore have greater efficiency!
- Reliability. Hydrogen fuel cell technology is both reliable and durable. A fuel cell contains far fewer moving parts than a combustion engine, reducing the likelihood of part failure and down time as the issue is diagnosed and repaired. They’re also reliable in that they do not require recharging as a battery would; a hydrogen fuel cell can continue to operate as long as hydrogen is available.
- Low noise. Another benefit of fewer moving parts and lack of combustion is that hydrogen fuel cells are less noisy compared to combustion engines. They do not produce noise pollution and hydrogen powered cars are, for the most part, near-silent when operated.
The UK’s hydrogen strategy contains includes a roadmap for developing a hydrogen economy, and hydrogen fuel cell technology is an integral part of it. Intelligent Energy is a leading, independent fuel cell specialist with a mission to power the future with our outstanding hydrogen fuel cell technology and services.
If you’d like to get in contact with us to discuss your business’ requirements or to find out more, please fill out our contact form. Our team is happy to help!
FAQs
Where does the hydrogen come from?
Hydrogen doesn’t exist in large quantities as a pure gas and therefore has to be extracted from other substances that contain hydrogen atoms. The source of hydrogen and the method used to extract it determines its “colour” in the hydrogen rainbow (grey, blue, green, etc.).
The colour will indicate to the user the method of extraction and the level of emissions generated from the production process.
Extracting hydrogen from natural gas is done through steam methane reforming and is classed as grey or blue hydrogen. Although the most available form of hydrogen at the moment, it is also highly polluting in grey form. When carbon capture is involved, the emissions are much lower and therefore class as blue hydrogen.
Generating hydrogen through gasification will create brown or black hydrogen and uses coal as it’s source. This is similar to grey hydrogen in the sense it is highly polluting.
Green hydrogen is the cleanest form of hydrogen production and is done via electrolysis. By using renewables, no emissions are released and this is therefore the cleanest way of obtaining hydrogen, however it is one of the harder routes at present due to the cost and availability.
What are the main parts of a hydrogen fuel cell stack?
A hydrogen fuel cell is a device that converts chemical energy (from hydrogen and oxygen) into electricity, with water and heat as the only byproducts.
The fuel cell itself is made up of various components that support this electrochemical reaction. The key components are the anode (negative electrode) where hydrogen enters the cell and the cathode (positive electrode) where oxygen enters from the air. The electrolyte – which in our case is the proton exchange membrane (PEM) – is where the reaction takes place as it allows protons in and sends electrons out via an external circuit, generating the electricity. Catalyst layers, gas diffusion layers and bipolar plates are also within the fuel cell.