The Role of Hydrogen in the Energy Transition
Decarbonizing the power sector is perhaps the most critical challenge faced by the global energy system while satisfying the rapidly growing energy demand.
In addressing this challenge, renewable energy plays a vital role. Nonetheless, it is unlikely to be able to do it alone.
Several different technologies and fuels would likely be required, such as hydrogen, which can play an essential role in the energy transition.
Hydrogen is the simplest element that contains a proton and electron. It is one of the promising energy carriers with the capacity to supply and store energy in operational form.
Hydrogen is readily available on earth but not in its pure form; it needs to be obtained from its compound.
Hydrogen is a clean fuel that produces water as a by-product when reacts in a fuel cell with oxygen.
The energy content of hydrogen lies between 142 MJ/kg (HHV) and 120 MJ/kg (LHV) that is three times higher in equal mass than petroleum.
Hydrogen can play a vital role in the energy transition, as it provides a safe, secure, and versatile solution for eliminating many barriers to a resilient, low-carbon economy.
Role of Hydrogen
1. Facilitates renewable integration
Image Source: Originenergy Australia
One of the crucial roles of hydrogen is in the integration of large-scale renewable energy by providing energy backup during power shortages and acting as a carbon-free long-lasting seasonal storage medium.
During over-supply, excess energy can be used to produce hydrogen by electrolysis. The hydrogen generated can then be used to provide back up power in power deficits or can be used in other areas such as transport, industry, and residential.
The storage solutions such as batteries, supercapacitors, and compressed air are available, but they do not have either power capacity or the required storage timespan to overcome seasonal imbalances.
Hydrogen is a novel way of energy storage. The use of hydrogen as a long-term storage method is expected to increase with a growing number of renewable energy sources.
It allows intermittent energy sources to be incorporated economically and provides flexibility to sustain the system’s resilience.
2. Distribution of energy across regions
Some countries are not well placed to produce wind or solar power electricity, and some may take time to raise investment.
In these cases, it may be more economical to import renewable energy. The transport of renewable energy at large and distance, or through sectors and regions, using hydrogen can be an attractive choice.
Hydrogen and its compound have high energy density and are easy to transport. Contrary to electricity, transportation of hydrogen over a long distance does not suffer energy loss.
3. Increases system resilience by acting as a buffer
It can also play a part in improving machine stability as a buffer.
Hydrogen is well suited to serve as an energy buffer and strategic reserve. The backup capacity of the energy system of today is held exclusively by fossil fuel carriers.
The use of fossil fuel as a backup will shrink in the future, requiring efficient buffer like hydrogen, which could transform into end-use applications.
4. Decarbonize transport
Image source: National Renewable Energy Lab
The decarbonization of the transport sector is another critical task.
Fuel cell electric vehicles (FCEVs) deliver many essential advantages, such as zero emissions, long-range, fast refueling, etc. For heavy-duty and long-distance vehicles, hydrogen as a fuel is an excellent choice.
FCEV infrastructure will expand on existing fuel distribution and retail substructure, generate cost savings, sustain local employment and capital assets.
Other than the reduction of carbon dioxide emission, the use of hydrogen in the transportation sector supports regional air quality improvements and noise reductions.
5. Decarbonize industry energy use
The energy for industrial processes is mostly provided by fossil fuels, which contribute 20% of global emissions.
The industry needs to boost energy efficiency, thus reducing energy requirements. The waste heat can be valorized using steam electrolysis technologies to produce hydrogen.
For low-grade heat uses like heating and drying processes, the industry can utilize hydrogen.
In the future, a combination of hydrogen burners and fuel cells will also be used by the industry to satisfy their low- and high-grade heat requirements.
Image source: Global CCS Institute
Hydrogen can also be used as feedstock with the captured carbon.
As a part of a circular economy or an alternative to carbon storage, carbon capture and utilization (CCU) need hydrogen to turn the captured carbon into functional chemicals such as methanol, methane, formic acid, or urea.
This use of hydrogen would make CCU a viable alternative to other sectors that are difficult to decarbonize.
Similarly, building heating can use hydrogen as a fuel or use hydrogen technologies, or preferably combine them: hydrogen technologies like fuel cell micro CHPs serve as energy converters.
They deliver high efficiency in the generation of heat and power and can itself be fuel either pure or blended with the gas partly decarbonizing the gas grid.
The global climate will be affected over the next 50 to 100 years unless the energy system changes in almost every respect, from power generation to end uses across the sectors.
The achievement of aggressive climate goals, such as reducing the global average temperature to less than 2◦C or even 1.5◦C demands drastic energy transition from non-renewable carbon-based energy sources to clean and low-carbon energy sources.
The unique features of hydrogen enable faster energy transition and support the energy system as well as end-use applications.
To accelerate the deployment of hydrogen storage technologies, the support and collaboration of policymakers, investors, researchers, the private sector, society, and countries are crucial.
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Council, H., 2017. How hydrogen empowers the energy transition. Technical report, Hydrogen Council, Belgium.
IEA (2019), The Future of Hydrogen, IEA, Paris https://www.iea.org/reports/the-future-of-hydrogen