green hydrogen It is becoming established as a key element in the decarbonization of the global economy and in the fight against climate change. In this context, the European Union has identified green hydrogen as a fundamental pillar in its Recovery FundWith an unprecedented stimulus package of 1,8 trillion euros, around 30% of the budget for this recovery is allocated to projects related to climate change. This is where green hydrogen emerges as a crucial element not only because of its energy applications but also for its ability to reduce CO2 emissions in sectors that are difficult to electrify. But what exactly is green hydrogen?
In this article we will discuss what green hydrogen is, its characteristics, types, applications and why it is considered one of the essential elements in the fight against climate change.
What is green hydrogen
Hydrogen is the most abundant chemical element on our planet, but in its natural state it is not found free, but combined with other elements such as oxygen in water (H2O) or in compounds such as methane (CH4). To use it as an energy source, it must be released from these combinations through separation processes, such as electrolysisThis process, which uses electricity to break down water molecules, is what allows us to obtain green hydrogen when the electricity used comes from renewable sources.
It is important to emphasize that green hydrogen is considered a energy carrier, not a primary source. This means that it stores energy that has been previously produced, rather than generating energy spontaneously, as fossil fuels do. Like lithium batteries They store electricity, hydrogen stores energy that can later be released in controlled processes.
One of the main advantages of green hydrogen is that it can be produced without generating carbon emissions, making it an ideal solution for sectors that are difficult to decarbonise, such as maritime transport, long-distance transport and heavy industry. In addition, it has enormous potential as a long-term energy storage system, since it allows energy to be accumulated during periods where available renewable sources (such as solar and wind) generate surpluses.
Origin and types of hydrogen
When we talk about hydrogen, we usually use a color classification which seeks to simplify and explain what the characteristics and environmental impact of the different production methods of this gas are. These colors do not reflect physical properties but the origin of hydrogenBelow we review the most common types:
- Gray hydrogen: It is the most widespread type in current production. It is obtained by means of natural gas reforming, a process that releases significant amounts of carbon dioxide. For each tonne of grey hydrogen generated, between 9 and 12 tonnes of CO2 are emitted.
- Blue hydrogen: It is also produced from natural gas, but unlike grey gas, this hydrogen has technologies that capture and store the CO2 emitted, considerably reducing its impact on the environment. This process is carried out by carbon capture and storage (CCUS).
- Green hydrogen: It is the cleanest of all. It is obtained by using renewable energy to carry out the electrolysis of water. During this process, no greenhouse gases are generated, making it the only truly sustainable option for the long-term use of hydrogen.
While the electrolysis process used in green hydrogen production is essentially simple — using energy to split water molecules into oxygen and hydrogen — the real challenge is doing it cost-effectively. This requires both abundant and cheap renewable energy such as technological advances in electrolysers that allow for efficient and scalable production.
Uses of green hydrogen
Green hydrogen has a growing number of potential applications in various industries, although the challenge of economic competitiveness remains important. However, as production costs come down thanks to technological improvements and the reduction in the cost of renewable electricity, green hydrogen is expected to play a crucial role in a carbon-free economy. Below we detail some of its main applications:
- Heavy industry:Green hydrogen can replace fossil fuels in sectors such as energy production. steel y cement, two major emitters of CO2, helping to reduce the carbon footprint.
- Energy storage: One of the most promising uses of hydrogen is its ability to store energy in the long term. During times of high renewable energy production, such as sunny or windy days, the surplus can be used to produce green hydrogen, which can be stored and used later when energy demand is high.
- Transport:Although electric vehicles currently dominate the light transport market, green hydrogen is a technology that is being seriously considered for the heavy transport (trucks, trains, planes and ships).
- Heating and gas networks: In certain areas, especially in Nordic countriesGreen hydrogen can be used in residential and industrial heating, achieving further emissions reductions. In addition, some natural gas networks could be adapted to transport a mixture of natural gas and hydrogen (up to 20%), which would significantly reduce CO2 emissions.
Economic and environmental benefits of green hydrogen
Green hydrogen is not only beneficial for the environment, but can also have enormous positive economic impactAccording to estimates by the International Renewable Energy Agency (IRENA), the cost of producing green hydrogen could decrease by 40% to 80% in the coming decades, making it competitive with other fossil fuels and opening up new economic opportunities.
On the other hand, green hydrogen offers a viable solution to meet the commitments of the Paris Agreement and net zero emissions targets which several countries have committed to achieving by 2050. This makes it one of the key technologies to combat climate change and ensure a sustainable future.
Both European Union countries Like other economic powers, they are investing in green hydrogen projects, and this trend is expected to continue in the next decade with initiatives such as the construction of electrolysers, transport networks and the installation of hydrogen stations.
Disadvantages of green hydrogen
However, despite its numerous benefits, green hydrogen also presents some challenges which must be overcome for their adoption to be massive and competitive in terms of cost:
- High production cost: Although costs are falling, the electrolysis process and the need for large amounts of renewable energy mean that green hydrogen is still considerably more expensive than other energy storage technologies, such as batteries or fossil fuels.
- Storage and transportationHydrogen is a light gas that requires specific (and expensive) infrastructure for its safe storage and transport.
- Availability of renewable sources:Green hydrogen production is entirely dependent on access to renewable energy sources. In places where renewable electricity generation is not abundant, its production can become difficult or expensive.
Despite these challenges, the long-term outlook for green hydrogen looks very promising.
With more and more energy companies and governments around the world committing to reducing carbon emissions, green hydrogen is likely to become an essential component of future global energy strategies. Moreover, technological development could help overcome many of its current obstacles.
Green hydrogen has the potential to transform industrial sectors, transport, energy storage and the energy market in general, helping to achieve ambitious climate goals in the coming decades.