Decarbonising the planet is one of the goals that countries around the world have set for 2050. To achieve this goal, the decarbonisation of an element such as hydrogen – currently responsible for more than 2% of the world’s total CO2 emissions – giving rise to green hydrogen, is one of the keys. Find out how it is obtained and what its impact will be in the coming decades.
Our lifestyle needs more and more watts to function. The latest estimates by the International Energy Agency (IEA), published in late 2019, predict a 25-30% increase in global energy demand by 2040, which in an economy dependent on coal and oil would mean more CO2 and worsening climate change. However, decarbonising the planet proposes a different world for 2050: more affordable, efficient and sustainable, powered by clean energies such as green hydrogen.
WHAT IS GREEN HYDROGEN AND HOW IS IT OBTAINED?
This technology is based on the generation of hydrogen – a universal, lightweight and highly reactive fuel – through a chemical process known as electrolysis. This method uses electricity to separate hydrogen from the oxygen in water, so if the electricity is obtained from renewable sources, we will produce energy without emitting carbon dioxide into the atmosphere.
This way of obtaining green hydrogen, as the IEA points out, would save the 830 million tonnes of CO2 per year that arise when this gas is produced from fossil fuels. Similarly, replacing all the world’s grey hydrogen would mean producing 3,000 TWh more renewable energy per year, equal to Europe’s current electricity demand. However, there are some doubts about the feasibility of green hydrogen due to its high production costs; reasonable doubts that will dissipate as the decarbonisation of the planet progresses and, consequently, as the costs of renewable energy generation fall.
HYDROGEN AS CLEAN ENERGY
Hydrogen is the most abundant chemical element in nature. Its global demand as a fuel has tripled since 1975, as the IEA points out, to 70 million tonnes per year in 2018. Moreover, green hydrogen is a clean energy source that emits only water vapour and leaves no residue in the air, unlike coal and oil.
The relationship between hydrogen and industry is long-standing. This gas has been used as a fuel since the early 19th century for cars, airships and spacecraft. The decarbonisation of the world economy, a process that cannot be postponed, will make it more important, and if its production becomes 50% cheaper by 2030, as predicted by the World Hydrogen Council, it will undoubtedly be one of the fuels of the future.
ADVANTAGES AND DISADVANTAGES OF GREEN HYDROGEN
This energy source has pros and cons of which we should be aware. Let us review some of its most relevant positive aspects:
- 100% sustainable: green hydrogen emits no polluting gases either during combustion or during the production process.
- Storable: hydrogen is easy to store and can be used for other purposes and at other times than when it was produced.
- Versatile: hydrogen can be converted into electricity or synthetic fuels and used for commercial, industrial or mobility purposes.
However, green hydrogen also has downsides that are worth mentioning:
- Higher cost: energy from renewable sources, the key to generating green hydrogen through electrolysis, is more expensive to generate, which in turn makes hydrogen more expensive to obtain.
- Higher energy costs: producing hydrogen in general and green hydrogen in particular requires more energy than other fuels.
- Safety concerns: hydrogen is a highly volatile and flammable element and therefore requires high safety requirements to avoid leaks and explosions.
IMPACT OF GREEN HYDROGEN
Hydrogen as a fuel is a reality in countries such as the US, Russia, China, France and Germany. Others, such as Japan, go even further and aspire to become a hydrogen economy. Here we explain what its impact will be in the future:
- Generating electricity and drinking water
These two elements are obtained by reacting hydrogen and oxygen in a fuel cell. This process has proven to be very useful in space missions, for example to supply crews with water and electricity in a sustainable way.
- Energy storage
Compressed hydrogen tanks are able to store energy for long periods of time and are also easier to handle than lithium-ion batteries because they are lighter.
- Transport and mobility
The great versatility of hydrogen allows its use in niches of consumption that are very difficult to decarbonise, such as heavy transport, aviation or maritime transport. There are already several such projects, such as Hycarus and Cryoplane – promoted by the European Union (EU) – which plan to introduce it in passenger planes.
HYDROGEN IN ITALY
Our country has not yet implemented concrete policies concerning the production and use of hydrogen. However, the PNRR plans to allocate the substantial sum of €3.7bn to projects involving this gas. Italy’s goal, in line with that of all other countries in the community, is to massively increase the spread of hydrogen throughout the country in the coming years.
The policies that will be undertaken to foster the spread of hydrogen are as follows:
- The development of pilot projects for the use of hydrogen in industrial sectors where it is difficult to reduce emissions otherwise
- The redevelopment of brownfield sites through the creation of Hydrogen Valley
- The use of hydrogen in heavy transport and on railway lines that cannot be electrified
- Support for research and development
- Regulations and reforms to enable the production, transport and use of green hydrogen.