When we talk about clean energy, the sun and the wind take almost all the spotlight. But there is a word that is sounding stronger and stronger in industry and transport: green hydrogen. It is not a passing fad. For many experts, it is the missing piece needed to complete the energy transition.
What it is, in plain words
Hydrogen is the most abundant element in the universe, but we rarely find it alone in nature. It is almost always combined, above all with oxygen forming water or with carbon in fossil fuels.
To use it as energy, it first has to be separated. And there is the key: depending on how it is obtained, hydrogen is more or less clean.
Most of the hydrogen produced today is extracted from natural gas, a process that emits a lot of CO₂. That is gray hydrogen. In contrast, green hydrogen is obtained by splitting water using renewable electricity, emitting practically no carbon at all. Hence its name and its appeal.
Why it matters now
There are sectors where electric batteries are not enough. Think of a long-haul truck, a ship, an airplane or a steel mill. Moving all that energy with batteries is very difficult: they weigh too much, take time to charge and do not perform the same over huge distances.
For those cases, hydrogen offers a clear advantage: it refuels in minutes and stores a lot of energy in little weight, like a traditional fuel, but without the emissions. In other words, it does not compete with the electric car in the city: it complements it where the plug does not reach.
The challenge: it is still expensive and scarce
The big problem with green hydrogen, today, is price. Producing it with renewables is still more expensive than gray hydrogen, and than natural gas directly. In addition, it requires enormous investments in electrolyzers, plants and distribution networks.
Spain has an important card to play: plenty of sun and wind to produce cheap electricity, and green hydrogen projects are already being promoted in the south of the country, partly intended for export to Europe. It is no coincidence that several major European projects are looking at the Iberian peninsula.
Where we are heading
Experts are not talking about a future in which hydrogen replaces everything, but about a future where each technology does what it does best. The city car will remain electric. But ships, trucks, heavy industry and large-scale energy storage have a serious candidate.
Green hydrogen is not a magic solution, and no serious person presents it as such. It is a medium- and long-term bet, with its costs, its challenges and its promises. But in the race to decarbonize what cannot be plugged in, today it is the best card on the table.
And that is, probably, the most useful way to understand it: not as the fuel of the future for everything, but as the piece that completes the puzzle of clean energy.
