New Delhi: Hydrogen, the lightest and most abundant element in the universe with atomic number 1, is making headlines in the world of science and energy these days. Traditionally known for its weightlessness, hydrogen is now gaining mass – in terms of importance, investment, and potential. Why is hydrogen (H₂), the first element on the periodic table, attracting so much attention? Does it have the potential to transform the future energy landscape?
Hydrogen is the simplest and lightest element in the periodic table, consisting of just one proton and one electron. It can be stored and does not generate pollutant emissions by itself. Despite its minimal mass of about 2.01568 g/mole, it packs a heavy punch when it comes to its potential applications in the energy sector. You might have heard that hydrogen is a renewable fuel, but this is not always true. Hydrogen is only renewable if the process used in its extraction is also renewable. This is why researchers and industries around the world are seeing that the path towards carbon neutrality goes through Green Hydrogen. Hundreds of billions of dollars are being invested into projects aimed at helping achieve net-zero targets and creating zero-emission fuel.
One might be confused with the colourful variants that are used to refer to the gas: Green, Grey, Blue, Brown and even Yellow, Turquoise and Pink. The rainbow of colours do not signify any change in the make-up of the element but they are essentially colour codes used within the energy industry to differentiate between the types of hydrogen on the basis of its production. So, despite so many colourful names, there is no visible difference between the different types of hydrogen.
When Hydrogen is produced from water using Renewable Energy (RE), along with zero carbon emission, it is termed Green Hydrogen. Grey hydrogen is produced from natural gas through a process which yields carbon dioxide. Brown hydrogen is made from brown coal or lignite and black hydrogen is made from black coal via gasification, which also yields carbon dioxide. If the carbon dioxide produced in the process is captured and prevented from getting released into the atmosphere, Hydrogen produced in the process gets termed 'Blue.' Hydrogen made through electrolysis of water using solar energy is termed Yellow Hydrogen. Turquoise hydrogen is made using a process called methane pyrolysis which produces hydrogen and solid carbon which can be used by industries. When water is electrolysed using nuclear energy, Hydrogen produced in the process is termed Pink Hydrogen.
One of the most significant factors driving the popularity of hydrogen is its environmental friendliness. When used as a fuel, hydrogen produces only water as a byproduct. This makes it an ideal candidate for a clean energy source, helping to combat climate change and reduce carbon emissions.
Although hydrogen is lightweight in terms of mass, it boasts a high energy density. This means that a small amount of hydrogen can store a substantial amount of energy. Hydrogen fuel cells, for example, can be used to power vehicles, homes, and industries, offering a clean and efficient energy solution.
Hydrogen's versatility is another reason for its growing importance. It can be used in a variety of sectors, from transportation to industrial processes and even in energy storage. Its ability to be used in multiple applications makes it a valuable asset in the energy transition.
Hydrogen can address one of the significant challenges of renewable energy sources like wind and solar power – their intermittency. Excess energy generated during peak production periods can be used to produce hydrogen through electrolysis, and then the hydrogen can be stored and used when needed. This would work exactly like a fuel cell used in vehicles, only larger in scale. In a fuel cell, Hydrogen is passed through an anode and air is fed into a cathode. A catalyst at the anode splits Hydrogen molecules into protons and electrons, which take different paths. The electrons go through an external circuit and its flow creates electricity.
Setting up large-scale Hydrogen fuel cells after driving down the cost of Hydrogen production is India's best bet to tackle the problem of intermittency of Renewable Energy until Battery Energy Storage Systems (BESS) can be commercially deployed.
As the world shifts towards more sustainable energy sources, hydrogen is gaining weight as a key player in this transition. Many countries are investing heavily in hydrogen technologies and infrastructure, recognising its potential to reduce dependence on fossil fuels and improve energy security.
The Hydrogen produced using clean electricity from renewable energy sources, such as solar or wind power, to electrolyse water is called Green Hydrogen. This process involves breaking down the water molecule (H2O) into oxygen (O2) and hydrogen (H2) by a direct electrical current that is connected by electrodes to the water. When electrolysis is performed with renewable energy, this is the most sustainable method of production.
While hydrogen's potential is substantial, there are challenges to overcome.
Production Methods: The most common method of producing hydrogen is through steam methane reforming (SMR), which relies on natural gas and produces carbon dioxide. The cleanest method for producing Green Hydrogen is electrolysis, but the cost remains high. There are three main challenges: the raw materials (Critical Minerals) used for building electrolysers, the cost of building the equipment, the cost of renewable energy used for electrolysis and the cost of distilling water for the process. There is a need to develop cheaper and alternate methods of producing Green Hydrogen.
Infrastructure development: Building the necessary infrastructure for hydrogen production, distribution, and storage is a costly and complex process. This includes the development of hydrogen fueling stations and transportation networks.
Storage and Transportation: Hydrogen is challenging to store and transport. It requires high-pressure or cryogenic conditions, which can be costly and energy-intensive. Developing efficient storage and transportation solutions is essential.
The lightest element on the periodic table is gaining weight in the energy sector, thanks to its potential to revolutionise how we produce and consume energy. Hydrogen, with its environmental benefits, high energy density, versatility, and ability to complement intermittent renewable energy sources, is becoming a key player in the global energy transition. As technology and infrastructure continue to advance, hydrogen's weight in the energy industry is likely to increase, making it an essential component of a sustainable and clean energy future.