What is Hydrogen?
MSc Innovative Sustainable Energy Engineering from the Norwegian University of Science and Technology (NTNU). Data science. Previously worked in electricity industry in Australia.
Table of contents
- Hydrogen is an elemental energy source, and can be produced from fossil fuels, or electrolysis (green).
- Sees most usage in industry, with limited energy applications although will likely play a large role in decarbonising EU power sector.
- Comparable to biomethane as a gaseous energy carrier, can use similar infrastructure.
- Currently limited avenues for transacting green hydrogen certificates, although existing renewable gas registers can be adapted.
What is hydrogen?
Hydrogen, the most abundant element in the universe, is an energy source that can be produced in a wide variety of ways. It can be produced from fossil fuels, including natural gas and via electrolysis where water is split into its elemental components, hydrogen and oxygen.
Is hydrogen renewable?
The by-product of hydrogen when used for energy production is water with no carbon dioxide; such energy production can be considered zero emission. As a result, hydrogen can be renewable a renewable fuel provided that there are no net carbon emissions in the hydrogen production chain.
From a sustainability point of view, hydrogen can fall into one of three categories:
Produced using fossil fuels (using coal gasification if coal is the feed, steam methane reforming when using natural gas), with the side effect of releasing net CO2. As a result, such hydrogen cannot be considered renewable.
Essentially grey hydrogen but using carbon abatement technologies (usually carbon capture and storage, or CCS) resulting in no or low overall carbon emissions in the blue hydrogen life cycle. As a result, blue hydrogen is considered renewable.
Hydrogen produced via electrolysis where the electricity is provided by renewable sources. As no carbon is released in the electrolysis process, and the electricity consumed is green, green hydrogen is considered renewable as the name suggests.
Applications - current and potential
The majority of the current usage of hydrogen is in non-energy applications. Much of the hydrogen produced currently is used to manufacture ammonia, which can be used to produce fertiliser. Hydrogen is also used heavily in oil refineries, in a number of chemical processes including hydrocracking (to produce transport fuels) and desulfurisation.
As an energy source, it sees limited use as a transport fuel. Hydrogen can be used in fuel cells, which are an emerging technology competing with batteries. Hydrogen fuel cell public buses are often promoted heavily, but the technology can be applied to other vehicle types as well.
Hydrogen in fuel cells can be used for electricity storage and generation, but currently there are significant limitations with efficiency and costs. This may change in future with improving technology and a reduction in renewable electricity prices.
Like methane, it can be compressed and conveyed using pipelines or transported via in tanks. The liquefying of hydrogen (similar to producing LNG from methane) for large-scale transport is currently not practical, although this is a developing field.
Blending with natural gas
Much research has been performed on blending hydrogen into natural gas streams, albeit at low proportions (10% by volume). While hydrogen and methane are chemically different gases, they can be mixed and a low hydrogen blend will have similar energy characteristics to pure natural gas. This would allow hydrogen to take advantage of existing natural gas infrastructure which would add to convenience.
Furthermore, it may be possible to use separation and purification techniques downstream to extract hydrogen from a blended hydrogen-natural gas stream if offtakers require a pure product for use.
Hydrogen and European decarbonisation
While hydrogen currently makes up less than 1% of the European energy mix, renewable hydrogen is seen as an important fuel in the decarbonising path forward given its potential in electricity storage, and as a gaseous fuel. This is in addition to its decarbonisation potential for non-energy applications such as steelmaking and fertiliser production.
The key to unlocking the potential of hydrogen lies within blue hydrogen. This allows fossils fuels to be utilised for hydrogen production without penalties (or much lower penalties) for carbon emissions, which makes it an attractive proposition for countries with substantial fossil fuel industries.
While green hydrogen is preferable in the long term, the rate of hydrogen uptake within a decarbonised EU likely depends on rapid deployment of hydrogen production capacity, in which case blue hydrogen will play a large role in the interim given the availability of feed materials (fossil fuels) and current lower production costs compared to green hydrogen.
Renewable hydrogen certificates
The market for renewable hydrogen is much smaller than that for renewable electricity. However, there are a few systems and considerations in place currently including:
- The CertifHy register is an EU collaboration led by HINICIO, and handles green and low-carbon hydrogen Guarantees of Origin (GOs). It has been operating for the last few years. 12.6 GWh of green hydrogen GO issues were recorded with CertifHy for 2021 production. Green Hydrogen GOs see a substantial amount of expiry (27% of all 2021 production issues as of April 2022), which likely reflects the relative infancy of this market, and lack of consumer awareness in H2 GOs.
- The REGATRACE EU project aims to promote renewable gas GO trading in the EU and have highlighted a work package (WP 4) which specifically mentions hydrogen.
While most current renewable gas registers are tailored towards biomethane and biogas, there is no reason such systems cannot be extended to encompass renewable hydrogen.
Comparison to biomethane
Given that both hydrogen and methane are gaseous energy carriers with the potential to be sustainable fuels, it seems natural to compare the two. A brief comparison is given below:
Renewable hydrogen is an emerging green commodity, and Greenfact is monitoring market developments in this field. If you wish to find out more, please get in contact with us.