The current hydrogen versus battery debate (or ‘battle’ as some like to call it) is not conducive to a wider deployment of clean energy. Industry stakeholders, instead of trying to elbow one of both technologies out of the market to make the other succeed, must start to think of a more holistic approach. Only by including all accessible green technology means we can achieve a fully sustainable society.
In the latter, hydrogen is one important piece of the puzzle. Although, around 40% less efficient for the usage in transportation than battery-electric driven vehicles, it is by far the most efficient energy carrier, capable of storing 210-times more energy per kilogram than commercial lithium-ion batteries.
Depending on its generation process, hydrogen is classified into grey, blue or green hydrogen. Grey hydrogen is obtained from fossil fuels, primarily through the steam reforming process. It represents more than 96% of today’s used hydrogen, which is bad news as one kilogram of grey hydrogen produces around 9.3 kilogram of CO2. As a comparison, the energy equivalent of 1kg H2 is one gallon of gasoline, which produces 9.1 kg of CO2 when combusted, evidencing the need for a cleaner H2 production. Blue hydrogen is initially obtained in the same way as grey hydrogen. Thus, this process also emits CO2. However, in this case hydrogen is not grey, and becomes blue, i.e. more climate-friendly, because the resulting CO2 is captured directly after the production process before reaching the atmosphere. Green hydrogen is the end product of an electrolysis process that is carried out entirely with renewable energies, thus 100% clean. The bad news here is that green hydrogen to this day is more than 3-times more expensive than grey hydrogen, which impedes a wider market demand. Nevertheless, as confirmed by the President of the European Commission, Dr. Ursula von der Leyen, “only green hydrogen will bring us to climate neutrality”, which is why in science and industry there is special focus put on reducing costs and upscaling green hydrogen and its infrastructure for production, storage and deployment.
Text by Dr.-Ing. Félix Urbain