Hydrogen: The fuel of the future ?

As a clean and harmless gas, hydrogen has many assets in the perspective of the energy transition. But it also has some major drawbacks, which can be overcome by integrating it into a wider energy production chain…

Trains running on hydrogen will soon be running in Germany, Italy, and France. Buses are already running on hydrogen in Pau and Dijon in France, while the range of private cars capable of running on hydrogen continues to grow every year. After years of research and experimentation, hydrogen finally seems to have reached the status of an operational "fuel", present in everyday life. It is true that on paper, this neutral gas, without taste or smell, has many advantages.

A 100% clean gas

The main advantage of hydrogen, making in it an attractive candidate for the energy transition: When used in an engine or a fuel cell*, it emits only water vapor. Nothing else. No CO₂ or other greenhouse gases, and even fewer pollutants such as nitrogen oxides or particles. The perfect green "fuel". The only problem is that this gas, which is abundant in the universe, does not exist naturally on Earth. There are no hydrogen deposits. It must therefore be produced, by electrolysis or using chemical processes. Solutions that consume a lot of energy and therefore seriously affect its carbon footprint and therefore its interest. However, this disadvantage does not put hydrogen out of the game, far from it. In fact, everything depends on the energy used for its production. If the latter is based on fossil fuels such as oil or coal, the balance sheet is not great. If, on the other hand, it is based on green energies such as wind or photovoltaic, this clean and harmless gas has some serious trump cards up its sleeve.

Producing hydrogen with renewable energies

Hydrogen can be used as a sort of adjustment variable in the production of renewable energies. As we know, renewable energies are "intermittent", meaning that they depend on the weather, the wind, and the sun, and therefore do not always supply the electrical network at the right time, in phase with consumption needs. One of the avenues being explored is not to disconnect these energies from the grid when they are not producing at the right time, but rather to use this surplus energy to produce hydrogen. This can then be used either to produce electricity again later, or be used as a "fuel" in adapted vehicles such as cars, buses, or trains.

A place in the energy mix

This mechanism has a cost, of course. But it avoids renewable energies producing "for nothing" and allows for the production of "green" hydrogen, almost decarbonized. A green hydrogen production station is currently under construction at the Toulouse-Blagnac Airport in France. Fueled by green energy from the entire region, it will produce hydrogen fuel for a fleet of five buses and a rental service of 50 vehicles. Another part of the hydrogen will be consumed by the platform's equipment, in order to reduce its carbon footprint. Projects of this type are expected to multiply rapidly in the region. So, even if hydrogen is not the miracle fuel that some would like to see, this gas can find its place in the energy mix and contribute to the decarbonization of the economy, thus contributing to the global decarbonization of energy, for the benefit of the climate.

*Fuel cell: A device that converts hydrogen into electricity by bringing it closer to the oxygen in the air.