For decades, hydrogen has been presented as one of the fuels of the future. Capable of storing renewable energy for long periods and generating electricity without emitting carbon dioxide, it has starred in countless pilot projects, industrial promises and government plans. However, a large part of these initiatives were still confined to laboratories or technology parks.
Now a new milestone has just occurred in Spain, more precisely in Bermeo, the most populated town in the Urdaibai Biosphere Reserve. There, for the first time, A large-scale engine powered exclusively by hydrogen has supplied electricity to a real power grid. The test, carried out in the Biscayan town of Bermeo by the Finnish company Wärtsilä, represents the first practical demonstration of a generator connected to the grid that runs on 100% pure hydrogen.
At first glance it might seem simple. If we can burn gasoline or natural gas to produce electricity, why not do the same with hydrogen? The reality is much more complicated. Hydrogen is a particularly difficult fuel to handle. It is extremely light, ignites easily and behaves very differently from conventional fossil fuels. Adapting industrial engines to run exclusively on hydrogen requires redesigning injection systems, combustion chambers and control mechanisms capable of withstanding very different conditions.
The installation used in Bermeo uses a Wärtsilä 31H2 engine, described by the company as the largest engine in the world designed to run solely on hydrogen. During the test, it managed to generate electricity and inject it into the Spanish grid under real operating conditions.
The question is inevitable: why not use batteries directly? The answer has to do with one of the main problems of renewable energies. The wind doesn’t always blow. The sun does not shine twenty-four hours a day either. When there is excess renewable production, that energy can be used to make hydrogen through electrolysis, splitting water molecules into hydrogen and oxygen. That hydrogen can then be stored for weeks or even months and used when the grid needs additional power.
In a sense, hydrogen works like a giant chemical battery… with a longer, cleaner lifespan. Proponents of this technology believe that it could become a key piece to stabilize future electrical networks dominated by renewable energies. Instead of relying on natural gas plants to meet peak demand, operators could turn to engines fueled by hydrogen previously produced using renewable electricity.
However, significant obstacles still remain. The main one is efficiency. Every time electricity is converted to hydrogen and subsequently back to transformed into electricity, a significant part of the original energy is lost. Furthermore, the storage, transportation and distribution of hydrogen require specific infrastructure that is still scarce and expensive.
That is why many experts consider that hydrogen will not replace batteries, but will occupy a different niche. While batteries are ideal for storing energy for hours or days, hydrogen could be a solution to store energy on a large scale for weeks or even entire seasons.
The test carried out in Bermeo does not solve all of these challenges, but it does demonstrate something that until now belonged mainly to the realm of theory: that a modern electrical grid can receive energy from an engine powered solely by hydrogen.And in a world that moves towards energy systems increasingly dependent on the wind and the sun, Having a way to store that energy for days when nature doesn’t cooperate could be just as important as producing it.