Hydrogen Hype

Hydrogen is an ‘energy carrier’ and can be produced from a wide variety of sources. Its market is well established, with global demand currently standing at around 8–10 exajoules (EJ) equals to 1.3-1.6 Billion Barrels of Oil Equivalent, most of which is consumed in the chemical sector. At present, roughly 95% of worldwide hydrogen production comes from fossil fuels. In this article, after introducing the basics of energy carrier, it will be described, why hydrogen is gaining such momentum and the reason it is more likely to be a hype than a hope for energy transition at least in short and medium term.

Let’s start with the basics. Energy sources are categorized in two groups: Primary Energy and Secondary Energy (Energy Carrier). Primary energy is an energy form found in the nature. This has not been engineered by humans in conversion processes. In an easy term, it is mainly raw fuels, and other forms of energy, including waste, received as input to a system. Primary energy can be non-renewable or renewable. This has been shown in the following figure.

Energy carrier (secondary energy) is the energy produced by converting so-called primary energy. There is always a transformation phase between primary energy to energy carrier. Electricity, refined automotive fuel, hydrogen and biofuels are all types of secondary energy.

Hydrogen is a form of secondary energy and it is the most abundant element in the universe, and it has one of the simplest and lightest elements in the world. Generating hydrogen and using that in industrial processes is not something new. However, increasing renewable generation and the volatile nature of renewables have made hydrogen as one of the ways of storing excess renewable energy. The process is straightforward: convert excess electricity to hydrogen (electrolysis) and then use it in transportation or store it. Then, convert back the hydrogen to electricity (fuel cells) in peak consumption hours based on the need. This is shown graphically in the following figure.

The main application is to use the produced hydrogen as vehicle fuel. The hydrogen can be used in power systems for energy storage as well, but the economy and efficiency are far poorer than fuel vehicle. The main drawback of hydron is relatively low efficiency. This has been shown graphically below:

The efficiency of a hydrogen car is almost one third of electric cars and this is considered a major issue. The other drawback of hydrogen is lack of infrastructure and inflammability of hydrogen. Using hydrogen with limited application in industrial processes seems to be promising while hydrogen as vehicle fuel doesn't seem to gain a momentum.

The main advantage of hydrogen is to support managing the excess electricity from renewable resources. While this is highly needed in the power system, but the hydrogen generation would be still volatile. On the other hand, the technical and economic developments in battery and fast-charging technologies is picking up the pace much faster. This could soon make fuel cell electric vehicles, which run on hydrogen, superfluous in road transport.

Disclaimer: This article is purely my ideas and reflect and represent my personal views.

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