Green hydrogen could become the sustainable fuel to replace fossil fuels in sectors that are difficult to decarbonize.
What is Hydrogen?
Hydrogen is the most abundant element in the universe. In its purest form, hydrogen is usually a gas, is also one of the component parts of a water molecule, is colorless, and can be burned to produce heat.
Approximately 96% of the hydrogen consumed in Europe is produced through fossil fuels such as natural gas, emitting significant amounts of CO2 in the process.
TYPES OF HYDROGEN
We currently have several different technologies that allow us to obtain hydrogen. But not all of them are sustainable. A color code has been established to differentiate the four types, depending on the impact and emissions generated by each one:
• GRAY HYDROGEN: produced with fossil fuels and emits a lot of CO2.
• BLUE HYDROGEN: produced with fossil fuels using carbon capture and storage technologies (less polluting than gray hydrogen). About three-quarters of the hydrogen produced today comes from natural gas. Blue hydrogen could be an initial solution, while green hydrogen production capacity and storage for industries such as steelmaking get underway. But blue hydrogen does not eliminate carbon emissions, only reduce them.
• TURQUOISE HYDROGEN: produced by pyrolysis from natural gas, but it is still a fossil fuel and, as such, is not emission-free.
• GREEN HYDROGEN: a clean fuel that allows energy from renewable sources to be stored and used. It is already considered a substitute for fossil fuels in industries that are difficult to decarbonize and in heavy transport sectors such as shipping and aviation. Both governments and economic sectors have recognized that green hydrogen will be a fundamental pillar for a fully sustainable energy transition. The best known option for producing green hydrogen is the electrolysis of water from renewable electricity. It involves the decomposition of water (H2O) into oxygen (O2) and hydrogen (H2) gases by virtue of a direct electric current traveling through electrodes in the water.
HOW IS RENEWABLE HYDROGEN PRODUCED?
Renewable hydrogen, also known as green hydrogen, is produced by splitting water into hydrogen and oxygen using renewable electricity. The hydrogen is collected and used, while the oxygen is released as a by-product if there is no local need. The splitting process used is known as hydrogen electrolysis, a well-established technology.
WHICH SECTORS WILL BENEFIT MOST FROM THIS CLEAN FUEL?
• Sustainable mobility: hydrogen fuel cell electric vehicles (FCEVs) represent a revolution in the energy and transportation sectors by using a fuel with a zero CO2 footprint.
• Heavy transport: sectors that are difficult to decarbonize, such as air, sea and rail transport, will find a sustainable solution in green hydrogen. Replacing today's heavy fuels with hydrogen is not so simple. The lower energy density of hydrogen means that such modes of transport will have to be redesigned for heavier loads.
• Energy storage: thanks to its large volume and long lifetime, hydrogen will be able to be stored in the same way as strategic reserves such as natural gas and oil.
• Industry: hydrogen is already used as a raw material in the chemical industry to obtain ammonia, in the petrochemical industry for oil refining, and in metallurgy for steel production. To decarbonize fertilizer production and reduce agricultural emissions.
• Domestic use: several sustainable projects are already underway to replace the natural gas grid with a green hydrogen grid that supplies electricity and heat to homes without producing polluting emissions.
Advantages of Renewable Hydrogen
Renewable hydrogen comes with its own set of pros and cons. However, we believe the disadvantages will diminish as we advance our technologies and cost-effectiveness.
1. Renewable hydrogen is carbon-free.
2. It emits no pollutant gases and offers a zero-emission alternative to fossil fuels.
3. Renewable hydrogen can be produced locally.
4. There are at least three immediate uses for renewable hydrogen in the short term: to replace all uses of fossil hydrogen with renewable hydrogen; to use it in fuel cells in medium and heavy ground transportation; and to use it in aviation and shipping, using e-fuels based on renewable hydrogen.
The main disadvantages of renewable hydrogen relate to cost, as it is more expensive to generate and obtain than fossil hydrogen. For this reason, renewable hydrogen must embark on a journey of cost reduction and scale-up similar to what we have seen in wind energy.
Chile has made some ambitious pledges, committing to carbon neutrality by 2050 and pledging to close or reuse its 21 coal-fired power plants by 2040; its energy matrix is becoming increasingly cleaner.
The journey from fossil fuels to green hydrogen has only just begun. Big developments are expected from hydrogen as a major player in sustainable development.
At VOGT we promote practices based on the intelligent use of water, through innovative, safe and reliable solutions aimed at solving problems in contexts of increasing water scarcity, environmental pollution and climate change. We invite you to learn about our new solutions associated with Green Hydrogen.