Scotland to gain extra production edge with hydrogen ‘bank’?

Researchers at the University of Aberdeen are pioneering technology that can store renewable energy as green hydrogen within depleted oil and gas reservoirs. This innovative approach not only contributes to Scotland’s net-zero goals but also positions the country to potentially become a hydrogen net exporter. It offers a promising future for previously exhausted oil and gas reservoirs, aquifers, and associated infrastructure like pipelines and wells.

One notable benefit of this technology is its ability to address the challenge of excess electricity generation from wind farms. By converting surplus electricity into green hydrogen and storing it for later use, the need for constraint payments to windfarm operators, who halt production during periods of high generation, could be reduced significantly.

Additionally, the Scottish Government’s investment in the Hydrogen Backbone Link project emphasises the pivotal role hydrogen could play in Scotland’s vision of becoming a net exporter of green energy.

The first phase of these projects which is already underway uses a combination of modelling, simulation and laboratory experimentation to evaluate the most effective means of transporting hydrogen through the onshore and offshore North Sea pipeline network, with the aim of developing digital tools that will enable transportation to homes and businesses.

It is also investigating the co-storage of hydrogen and carbon dioxide in depleted hydrocarbon reservoirs and aquifers, with CO2 acting as a ‘cushion’ gas. This technique has never been attempted before but could be used to store blue hydrogen and the associated CO2 at a large scale. Meanwhile, the second phase will focus on field trials and commercialisation through the potential formation of a spin-out company to drive forward the technology.

Dr Prashant Jadhawar from the University’s School of Engineering who is leading the projects, said that the development of these technologies is a potential “game-changer” which could play a major role in helping Scotland meet its target of 5GW of green and low-carbon hydrogen production (equivalent to a sixth of the country’s energy needs) by 2030.

“This target relies on there being sufficient hydrogen storage capacity which only subsurface geological formations such as depleted hydrocarbon reservoirs or aquifers can deliver on such a large TeraWatt (TWh) scale,” he explained.

“Through our current research we have estimated up to a 20 TWh hydrogen storage capacity, as well as the permanent sequestration of 50 million tons (Mton) of CO2 in a single UKCS reservoir investigated so far.

“By offering the safe and effective storage of bulk quantities of hydrogen and CO2, our project offers a unique opportunity to help Scotland meet its hydrogen production targets as well as offering the potential for Scotland to become a net exporter of hydrogen.

“It will also help extend the life of depleted oil and gas reservoirs and associated infrastructure, helping ensure a continued and important role for the North Sea in the net zero economy.”

Ekua Osei, Project Engineer at NZTC said, “We’re excited to see innovation playing a key role in enabling and enhancing Scotland’s hydrogen production, storage and export capability. This project could evolve current practises and allow electricity from wind farms to be stored rather than production being halted.

“As we transition from a legacy energy source to new vectors and more sustainable sources, it’s important that we do so in an environmentally conscious way, whilst reusing and repurposing the existing transportation pipelines and reservoirs. These projects at the University of Aberdeen align with this.”