Gas fields in the southern North Sea could use existing infrastructure and large offshore wind developments to develop large scale offshore hydrogen production, a study has found.
Researchers from the School of GeoSciences at the University of Edinburgh had sought to assess the hydrogen storage capacity of the UK continental shelf (UKCS). Publishing their findings in the International Journal of Hydrogen Energy, they found 6,900TWh of working gas capacity in gas fields, with the majority of this (85%) in the southern North Sea and in close proximity to either existing or planned large scale offshore wind developments. These could be used to produce hydrogen which could then be injected into seasonal energy stores in future, the researchers suggested.
With increased penetration of renewable energy sources, along with decarbonisation of the UK’s gas supply, large scale energy storage is needed with hydrogen a potential option as an energy storage vector. The researchers had forecast a need of 150TWh of seasonal storage to replace seasonal variations in natural gas production, with low temperature/high pressure capacity storage sites identified as best.
Using data that had previously been used to assess CO2 storage potential, the researchers quantified the hydrogen storage capacity of gas fields and saline aquifers, finding 9,100TWh in total – 6,900TWh in gas fields, together with 2,200TWh in saline aquifers on the UKCS. Furthermore, 29 of the gas fields were found to be situated 10km or less from wind developments, with this the case for 21 of the saline aquifer storage sites. While this offers substantial potential for hydrogen production with the gas fields, the researchers were more cautious on providing accurate estimations of hydrogen storage capacity in the saline aquifers, stressing it was a “low confidence” estimate.
Looking ahead, the researchers said further refinement of the study would need to consider the potential conflict with CO2 storage sites, potential reactions between hydrogen and existing fluids in the gas fields, such as natural gas, carbon dioxide and hydrogen sulphide, as well as well integrity.