When even Bill Gates is investing in a new low-cost renewable hydrogen process, the chances are that this energy source has a bright future.
Yes, you read it correctly – we are talking about RENEWABLE hydrogen. Because to be viable, generation from this energy source has to be renewable, or at least decarbonised, which is still far from being the case today. Could it replace fossil fuels for good? Will sustainable transport make it the world’s new fuel? Caroline Mazzoleni, Deputy Head of the New Renewable Energies division at Bouygues Energies & Services, gives us an overview of the outlook and conditions for developing this energy.
One of the challenges of the energy transition is the ability to generate and store renewable energy. As decarbonisation has become a key challenge in the world today, it is vital to invest in power generation methods that are clean, reliable and competitively priced. We want to generate a lot, at a low cost, with the least possible pollution, and we want to match the periods and locations of generation with consumers’ energy needs. The problem? The proportion of renewables in the overall energy mix is still low and meeting all of the above criteria is not always straightforward.
Rising to the challenge of decarbonising the planet
Renewable hydrogen, generated from renewable electricity, is storable, as well as being non-polluting and sustainable .
Hydrogen is an essential tool for speeding up the energy transition. This energy source opens up a number of potential ways to meet the challenges of decarbonisation:
- decarbonising transport, especially heavy transport,
- decarbonising industrial processes by replacing fossil hydrogen with renewable hydrogen in industry
- using hydrogen as a power source as a solution for storing renewable energy or supplying it on isolated sites.
“For hydrogen to be integrated into the energy transition value chain, particularly for transport, it needs to be generated in a carbon-free way. It is a prerequisite if we are to make it an energy of the future. This is why we are working on several innovation projects around this energy”
declares Caroline Mazzoleni, Deputy Head of “New Renewable Energies” for Bouygues Energies & Services.
Generating green hydrogen through water electrolysis seems to be the most suitable solution so far. This is because hydrogen is generated from water and renewable electricity (solar, wind, hydroelectric, etc.). It is a well established and reliable process but the costs of generating hydrogen are still high. “The key to the business model is the proliferation of generation sites. This is a crucial step towards achieving a competitively priced renewable hydrogen fuel” continues Caroline Mazzoleni.

Green hydrogen storage: the great challenge of the years to come
The other advantage of hydrogen is its ability to store energy over long periods (between seasons). Hydrogen can take several forms: gas, liquid, or even solid, but it is mostly stored in gaseous form.
Making the future of clean transport a reality
We are living in an increasingly “green” era. Alternative fuels are gaining huge momentum in the market. Used as a fuel, hydrogen is an alternative to gas or electric vehicles. This is particularly important in situations that require a long range or short recharge time. It is therefore particularly suitable for heavy vehicles, where the weight of the batteries is too restrictive, but also for long journeys. Only water vapour is emitted during travel and it is very quiet – it is also a good way to reduce noise pollution in the city. For example, since 2019 Bouygues Energies & Services has been working on updating its vehicle fleet, seeking to replace diesel engines as much as possible with electric or hydrogen models in anticipation of low-emission zones, where it will be increasingly difficult to drive “conventional” vehicles.
In France, the hydrogen industry aims to deploy at least 5,000 light commercial vehicles and 200 heavy vehicles by 2023. Many industry players have already started to shift towards more sustainable business models, but a more suitable regulatory framework is needed to make renewable hydrogen projects accessible.
“Hydrogen vehicles are still very expensive. The industrialisation of hydrogen vehicle production should make it easier for all users to access an affordable vehicle fleet. This is why the hydrogen transport sector is being structured through heavy transport and so-called captive local fleets – buses, lorries, vans, refuse collectors – in other words, vehicles that make daily trips in a specific area.“
adds Caroline Mazzoleni
Hydrogen, an infinite resource?
Hydrogen is the most abundant element in the universe. It is the main component of most stars. However it is not available in its pure state. It can mostly be found in water (H2O) or in natural gases, such as methane (CH4).
It is commonly used in industry, refining and chemicals, and 95% of the hydrogen used is generated from fossil fuels. For example, the most common and cheapest practice is the generation of hydrogen from methane, but this is also one of the most polluting.
Fossil hydrogen generation is responsible for 11.5 Mt of CO2 emissions in France, i.e. about 3% of national emissions. It is therefore essential to generate it cleanly. It is therefore quite possible to see a future where heavy transport will be mainly based on hydrogen fuel, fundamentally reducing greenhouse gas emissions. In addition to road transport, this applies to shipping, railways and aviation.
What can we learn from the hydrogen solution?
The financial hurdle is still high, as the technologies needed to generate and use hydrogen are rapidly evolving. Although some systems are very promising, they are still much more expensive and less efficient than conventional “polluting” generation methods.
Although renewable hydrogen is not yet a silver bullet for the energy transition, its generation and the many innovations surrounding it will probably transform our way of life and power generation in the coming years.
Once the yields are more efficient and the costs lower, renewable hydrogen could indeed be the solution that decarbonises the planet.
Bouygues Energies & Services is convinced of the future of this energy source and is partnering with universities, start-ups and other companies on a number of projects involving the generation and storage of green hydrogen. For example, it has invested in the company Powidian, an innovative start-up specialising in the generation of autonomous hydrogen-based energy.
“In the meantime, we have to keep investing and innovating. In France, the government has pledged € 7bn over 10 years, including € 2bn by 2023, to develop a green hydrogen industry. I am confident in the future of this green energy”
concludes Caroline Mazzoleni

The SEPHER project (Secours Electrique par Pile à Hydrogène et Energies Renouvelables – Electric backup using hydrogen fuel cells and renewable energies) was launched in 2019 by the French air traffic authority Direction des Services de la Navigation Aérienne (DSNA). This innovative and environmentally pioneering trial project consists of implementing a CO2-free emergency power supply solution for civil aviation communication equipment used for exchanges between pilots and air traffic controllers.