If the capacity to deploy CCUS at a commercial scale is not met by 2030, ETI analysis shows there will be a significant increase in the cost of decarbonisation posing significant risks to achieving the reductions required for the 5th carbon budget and beyond. As part of its Carbon Capture and Storage programme, the ETI wanted to explore how you could maximise the potential savings CCUS could offer the UK, to further encourage initial investment in the technology.
Brine production is a technique that could potentially increase the capacity of aquifer CO2 stores. It works by releasing native water into the aquifer at the same time as CO2 is injected, alleviating pressure so that more CO2 can be stored. During the CCUS process, as CO2 is injected into saline aquifers, the pressure rises. Since each store has a limiting pressure, for integrity reasons, any increase in pressure can limit the storage capacity and CO2 injection rate – increasing costs. Knowing the importance of maximising the financial incentive for CCUS, brine production could increase the capacity of CO2 storage in saline aquifers, potentially saving the UK a calculated £2 billion.
ETI research has identified 575 potential Carbon Dioxide stores in UK waters, with a total storage capacity of 76,000 million tonnes. Only 10% of this storage capacity would be needed to deliver decarbonisation pathways containing CCUS to meet 2050 targets at the lowest cost. Research shows that there are “ready for business” stores but for these storage opportunities to become a reality there is a need to ensure any performance risk is manageable to better encourage investment.
What does this mean for the UK? With over 75% of the potential UK CO2 stores found in saline aquifers, using brine production can increase the capacity of these stores by as much as 20 years. This translates into a calculated £2 billion saving to the UK, when deployed as part of a CCUS implementation strategy. Most importantly, the research ETI has undertaken shows that we can enhance the capacity of cheaper CO2 stores rather than develop more expensive storage facilities to store the same level of CO2. With this, brine production can be deployed 5-10 years after the store has been commissioned, meaning operators have more time to assess how best to develop their asset in the long term.
Including brine production options during the appraisal stage of the UK’s CO2 storage sites means that we can add significant value to store selection and strategic planning. By enlarging cheaper stores using brine production this allows for changes to the optimal order in which infrastructure investments need to be made and can therefore reduce the overall costs of a CCUS rollout.
As CCUS re-joins the UK low carbon agenda, it’s important to realise that the UK is well placed with the skills, capabilities and expertise to commercially develop brine production for UK stores. After successfully deploying across the UK, brine production can then be offered as a service overseas, opening up wider export opportunities for the future.