Hydrogen (H2, molecular hydrogen) will likely play a crucial role in the future decarbonisation of the global energy mix.
Hydrogen is unique in that when burned for energy, it produces predominantly water as a byproduct, whilst yielding energy.
Hydrogen can be used therefore to produce low carbon energy for power, but also for heat, transport and industry – making it unique among some of the low carbon energy options as it is so versatile.
Currently, there are two main methods of producing hydrogen. Primarily, hydrogen is produced by a reforming process in which methane is combined with steam (water) to produce hydrogen and carbon dioxide. The alternative in by electrolysis, in which water is split into its individual constituent parts of hydrogen and oxygen. Currently,electrolysis is too expensive at large scale.
By coupling steam methane reformation with carbon capture and storage, the carbon dioxide produced in the hydrogen production process could be stored. If the process could be run using renewable power, then this would effectively be a clean and sustainable way of producing hydrogen and using fossil fuel resources.
Within the GeoEnergy research group here at the University of Edinburgh, much research is being undertaken in hydrogen storage. This focuses mainly on the storage of hydrogen underground in the subsurface geology.
There are several pros to this type of storage:
- Energy security is increased by having a secure supply of energy stored for when demand is high
- A fully renewable energy grid will likely need energy storage for periods when their supply is less than demand
- The subsurface is large, very large, and has stored gases (e.g. methane) safely for thousands of years before
- Much of the knowledge and infrastructure from other industries (e.g. petroleum sector) can be utilised
- Helps to tackle climate change, by decarbonising the energy mix, and assisting governments in meeting their climate change targets.
So, hydrogen is one to watch for the future and if you are interested in learning more then the MSc GeoEnergy here at UofE could be a good place to start!