Hydrogen might change the energy world as we know it. It could supply our energy needs, fuel our cars, heat our homes, and help to fight climate change. It’s also touted as the fuel to clean up our most carbon-intensive industries. We show you how.
Why all the fuss?
Hydrogen is the lightest and the most abundant element that we have in the Universe. Of course, it’s a key component of a substance we consider to be very important: water. Besides, as all living things are composed largely of hydrocarbons, hydrogen is everywhere around us.
Scientists estimate that hydrogen makes up approximately 73 per cent of normal matter by mass and more than 90 per cent of all of the atoms. It was produced artificially for the first time in the early 16th century by British scientist Henry Cavendish who recognised that hydrogen gas was a discrete substance and that it produces water when burned, the property for which it was later named (in Greek, hydrogen means “water-former”).
Hydrogen has one of the highest energy density values per mass which means that for every 1 kilogramme of mass of hydrogen, it has an energy value of 120-142 MJ. It’s colourless, odourless, non-toxic and highly combustible. Hydrogen burns cleanly. When it is burned with oxygen, the only by-products are heat and water.
How do we use hydrogen?
Hydrogen is already an enormous 100 billion US dollars per year market. It has long been used as a feedstock for industrial and chemical processes. Its use today is still dominated by industry, namely: oil refining, ammonia production, methanol production and steel production. In 2020, demand for hydrogen stood at 90 Mt, practically all for refining and industrial applications.
But with a global energy sector in flux, the versatility of hydrogen is attracting stronger interest from a diverse group of industries. Nowadays, we talk about it in the first place in the context of the energy sector, its application in transportation and industry. What is sure is that hydrogen can be used in many more applications than those common today.
How it is produced?
Hydrogen can be extracted from fossil fuels and biomass, from water, or from a mix of both. Natural gas is currently the primary source of hydrogen production. The most common method, steam methane reforming (SMR), reacts with natural gas with high-temperature steam. Gas is followed by coal and a small fraction is produced from the use of oil and electricity.
Today, hydrogen is produced almost exclusively from fossil fuels, less than 0.1 per cent of global dedicated hydrogen production comes from water electrolysis, which can result in zero greenhouse gas emissions, depending on the source of the electricity used. Electrolysis is a chemical process splitting hydrogen and oxygen from water using electricity.
Alkaline water electrolysis is the most established and widely used technology today given that it is cheaper and modular. Proton Exchange Membrane (PEM) technology is more recent with higher costs due to limited commercial applications but it’s better suited to transport applications and areas with variable renewables given quicker start-up time and operating range. As the cost of renewable electricity, in particular from solar PV and wind, is declining, there is growing interest in electrolytic hydrogen.
What are the colour codes?
As we established, hydrogen is colourless. We have come up with different colour codes to describe where it is sourced from. We call the hydrogen produced from gas or coal grey because it is a fossil fuel emitting process. On a global scale, grey hydrogen is responsible for almost 2 per cent of worldwide emissions. In 2020, hydrogen production resulted in close to 900 Mt of CO2 emissions.
Today in the context of the energy revolution we are mostly speaking about blue and green hydrogen. The interim step is called blue hydrogen, when we continue to use coal or natural gas but add Carbon Capture and Storage (CCS) to it, which aims to capture carbon emissions that would normally go into the air and heat up the atmosphere. That is technically considered to be a carbon-neutral or a low-carbon solution. The third option is green hydrogen when hydrogen is produced through electrolysis. As long as the electricity is renewable it can be considered green. When we talk about the hydrogen market today we talk predominantly about grey hydrogen. When we talk about the future of hydrogen we refer to blue and green hydrogen.
As we said hydrogen is not new. The technology has been around for decades but has yet to reach its tipping point in mainstream use. Against the background of global efforts to mitigate climate change, hydrogen can step in as an important element of cutting emissions.
The stars seem to align. The cost of renewable energy and electrolysers used to produce green hydrogen is decreasing and is estimated to fall between 60-90 per cent further before the end of the decade. Technology has also improved with better efficiencies and flexibility in fuel cells and electrolysers. Finally, a global focus on decarbonisation and sustainability is expanding potential end markets.
The role of hydrogen in the decarbonisation puzzle
Hydrogen will have the greatest effect on sectors where decarbonisation with electricity from renewable energy is not possible. In transport, fuel cells, in which hydrogen and oxygen are combined to generate electricity, could replace the combustion engine and even offset most of the downsides of battery-powered cars like range and recharging times. The most promising application of hydrogen fuel cell technology for the transport sector today is the heavy-duty municipal and rail transport sector.
Shipping and aviation also represent an opportunity for hydrogen-based fuels having limited low-carbon fuel options available. Green hydrogen can also be stored, distributed, and used as a feedstock for stationary power and industrial and manufacturing sectors such as steelmaking. Due to their high efficiency and zero-or near-zero emissions operation, hydrogen and fuel cells have the potential to reduce greenhouse gas emissions in many applications.
So what are we waiting for?
So hydrogen can help tackle various critical energy challenges. It offers ways to decarbonise a range of sectors where it is proving difficult to meaningfully reduce emissions. It can enable renewables to provide an even greater contribution. A wide variety of fuels are able to produce hydrogen, it can be transported as a gas by pipelines or in liquid form by ships. It can be transformed into electricity and methane to power homes and feed industry, and into fuels for cars, trucks, ships and planes. Sounds perfect, so why are we not all using hydrogen now?
Hydrogen doesn’t exist on this planet in its pure form, we have to separate it from other substances so we can store and use it, which requires time, energy and above all money. According to the IEA, putting the hydrogen sector on track for net-zero emissions by 2050 requires 1 200 billion US dollars (1 060 euros) of investment in low-carbon hydrogen supply and use through to 2030. Therefore, putting in place a policy framework to mobilise investment in production, infrastructure and factories will be crucial.
A key barrier for low-carbon hydrogen today; the cost gap with hydrogen from unabated fossil fuels can also disappear with time due to technology innovation, falling cost of renewables and increased deployment. Experts suggest that green hydrogen can become competitive already within the next decade in regions with excellent renewable resources.
All in all, there are encouraging signs of progress, but we still have a long way to go. Developing strategies and targets for low-carbon hydrogen production, stimulating demand, mobilising investment in production, infrastructure and factories and finally establishing a supportive regulatory framework will all be crucial to harnessing the full power of hydrogen.
Join the Budapest Hydrogen Summit on 10 March to learn more.