Hydrogen has many applications in the energy industry and it is widely used by various sectors. However, its production generates harmful carbon dioxide emissions which need to be reduced to prevent further global warming. Green hydrogen may be a cutting-edge solution that will significantly support energy transition.
According to the International Energy Agency (IEA), hydrogen consumption has been steadily growing since 1975. However, the problem is that its production relies almost entirely on fossil fuels whose use humanity must phase out.
At the moment, about 75% of the entire global production of hydrogen (70 million tons a year) is based on natural gas. The industry uses 6% of the total annual natural gas supply and 2% of the coal supply with only 0.1% of hydrogen being made from renewables, i.e., based on water electrolysis which results in green hydrogen that is not associated with greenhouse gases emissions.
All colors of hydrogen
Hydrogen is divided into colors according to the methods and sources of its production. Grey hydrogen is produced from coal or methane using the process of steam reforming of gasification so production of this generates a lot of carbon dioxide. Pink hydrogen is produced based on nuclear energy and although it is much less emissive than grey hydrogen, it is still not carbon neutral. Turquoise hydrogen is created as the result of the pyrolysis of methane and therefore also involves very potent greenhouse gas emissions in its production. Blue hydrogen, which is cheap to produce, is derived from methane and its main source is natural gas and although it is often presented as a low-carbon fuel, in fact, its production involves high emissions of CO2. Companies who produce blue hydrogen argue that emissions are reduced thanks to the carbon capture technology involved in the process whereby the carbon is stored or reused. However, the latest research conducted at Stanford and Cornell Universities and published in Energy Science and Engineering indicates that blue hydrogen production emits more carbon dioxide than previously thought as it involves the use of natural gas which means methane is also released in the process. According to this research, the process of producing of blue hydrogen from natural gas results in more emissions than burning natural gas alone.
Green hydrogen – the hope of energy transition
While the most popular methods of hydrogen production still contribute to high carbon emissions, there is a possibility of including hydrogen in the energy transition process for good thanks to green hydrogen. Its production emits hardly any greenhouse gases as it is based on renewables and the process of electrolysis when water is turned into hydrogen. Although its production is still expensive, IEA expects a real boom in green hydrogen production with the main producer currently being the EU. IEA projections state that the costs of production of green hydrogen will drop by about 30% by 2030 which will boost the industry as the costs of renewable energy are still decreasing. To support the development of green hydrogen, the world’s governments have announced US$30 billion in subsidies.
Why hydrogen is essential for energy transition
Hydrogen may emerge as being inevitable in energy transition, firstly to support renewable energy sources and it may also be able to cover the shortfall of electrical energy in the power grid. The storage of energy is one of the biggest challenges of energy transformation and hydrogen is not only a fuel but it can also store energy produced by renewables much more effectively than ion-lithium batteries which lose efficiency over time. Hydrogen may also be crucial to decarbonize transport, especially aviation or long-haul transport for which it is difficult to use ion-lithium batteries because they are both heavy and inefficient and, as the batteries need to be charged, this is almost impossible on long flights and journeys. In contrast, the fuel cells based on hydrogen are much more efficient and do not need to be charged as frequently. Finally, hydrogen is widely used in the chemical industry to produce ammonia which is necessary to produce fertilizers and steel, processes that must also be decarbonized if we hope to be climate-neutral by 2050.
