The war in Ukraine has highlighted the extent to which France and many other EU countries are dependent on energy, especially natural gas from Russia. To ensure its energy sovereignty, hydrogen is seen as one solution among many in France’s and the EU’s energy transition policy
Definition
Considered the lightest and most abundant chemical element or molecule in the universe, and present as a colorless, odorless and flammable gas, hydrogen is produced in a variety of forms and energy sources. This leads us to investigate the nature of hydrogen in two ways: as an energy carrier and as an energy source.
Hydrogen is an energy carrier.
Hydrogen production depends on other energy sources, which may be fossil, renewable, or decarbonized. Hydrogen is in fact produced from a primary energy source. This makes it an energy carrier. Article 811-1 of the French Energy Code classifies hydrogen energy carriers into different categories [1].
First, renewable or green hydrogen. This is hydrogen produced by electrolysis of water using electricity exclusively from renewable energy sources (wind, solar, hydro, biomass). For its part, the EU has placed the emphasis on renewable hydrogen through its Directive 2018/2001 on the promotion of the use of energy from renewable sources, known as RED II, with two delegated acts. Indeed, the first delegated act specifies the conditions under which hydrogen, hydrogen-based fuels or other energy carriers can be recognized as renewable fuels of non-biological origin (RFNBO) [2]. In addition, the rules of this delegated act aim to ensure that renewable hydrogen is produced exclusively from electricity from renewable sources, and meets the criteria of additionality, temporality and territoriality.
The second delegated act establishes methods for calculating greenhouse gas emissions over the entire life cycle of renewable fuels of non-biological origin. The method established by this act enables greenhouse gas emissions to be considered throughout the fuel’s life cycle, including upstream emissions, emissions linked to the consumption of grid electricity, processing and those associated with the transport of these fuels to the end consumer [3].
Secondly, « low carbon » hydrogen refers to hydrogen whose production process generates greenhouse gas emissions equal to or less than the threshold set for the qualification of renewable hydrogen. The European Union defines low-carbon hydrogen as low-carbon hydrogen whose energy content is derived from non-renewable sources, and which meets a threshold of 70% less greenhouse gas emissions than its fossil equivalent. The threshold, which is the same as for renewable hydrogen, is set at 3.38 kg CO2 eq/kg H2 based on a full life-cycle analysis [4]. Hydrogen produced from low-carbon energy sources such as nuclear power comes in pink form.
In addition, the other category of hydrogen considered as an energy carrier is carbonated hydrogen. It is neither renewable nor low carbon. It is produced mainly from fossil fuels (natural gas, oil, coal, etc.). When these fossil fuels are used without CO2 capture and storage, grey hydrogen is obtained. On the other hand, when CO2 is captured and stored, the hydrogen produced is in blue form. In addition to these three categories of hydrogen considered as energy carriers, there is also a category of hydrogen known as « co-product ». In other words, hydrogen is produced in an industrial process and consumed by the company itself. This type of hydrogen comes from chlorine and soda production processes, for example.
What about hydrogen as an energy source?
Hydrogen is an energy source
Hydrogen has long been considered a major energy carrier. However, recent scientific advances have highlighted its natural presence underground, where deposits can be found. This naturally occurring hydrogen, referred to as « white » or « native » hydrogen, is distinguished by its extraction method, which generates virtually no CO₂ emissions. From then on, white hydrogen production is considered decarbonized, giving this resource the status of an energy source with a low carbon footprint.
White hydrogen was first discovered in West Africa, more precisely in Mali, in the village of Bourakébougou in 1987. Today, this natural hydrogen deposit supplies the village with electricity. However, to date, Mali has neither the financial resources nor the technological capacity to exploit this hydrogen on a large-scale industrial scale. Nonetheless, this discovery paved the way for research that has now led to the discovery of white hydrogen in other countries such as France, Canada, the USA, Russia and many others.
However, while white or native hydrogen is of particular interest to those involved in the energy transition, there are still many scientific, economic, legal and environmental challenges to be considered.
Hydrogen is both an energy carrier and a source of energy.
For further informations:
[1] Article L.811-1 du code de l’Énergie
[2] La Commission établit des règles pour l’hydrogène renouvelable – Commission européenne
[3] Idem
[4] Biaggi, J. P ; Harry, C ; Chiron, F.X ; Hirson, P.C. Groupe de travail « Hydrogène bas carbone ». Introduction à la production d’hydrogène bas carbone : des technologies variées : voies électrolytiques, thermiques et géologiques. EVOLEN, avril 2024.
