It is accepted that UK energy networks face a number of unprecedented challenges in the upcoming decades. These challenges include the threat to the security of energy supply due to declining indigenous fossil fuel reserves, increased reliance on imported fossil fuel (78% of coal and 50% of natural gas are imported, it is predicted that gas import will be over 80% in 2020), and planned retirement of ageing generation capacity over the next decade (approximately 20GW or 25% of the existing generation capacity); decarbonising electricity generation to achieve the goal of 80% reduction in CO2 emissions by 2050; and coping with the future increases in electricity demand from electrification of transportation and space heating. To address these great challenges, it is recognized that the UK energy networks, must change, strategically and the existing regulatory arrangements should be examined to check if they are fit for the purpose of future energy network operations.

To ensure that power supply closely matches demand, the amount of electricity generated must be well controlled and managed. If the balance between supply and demand is broken and the difference exceeds a critical level, the power system may fail and cause a regional blackout. The UK is especially vulnerable in terms of network stability as it has a relatively isolated small island power network. Currently, 80% of our electricity is generated from fossil fuel (coal or gas) with the load balancing function mainly managed through fossil fuel peaking generation plants that respond to load changes. The mix of electricity generation in the UK will change dramatically with a large reduction in the use of coal and gas and an increase in the clean variable, intermittent renewable energy generators. The inherent energy storage capability that we currently enjoy due to our dependence on fossil fuel power generation will then be greatly reduced by 2030.

Solutions are needed to address the network challenges that will occur due to a decrease in the implicit energy storage available with the planned reduction in fossil fuel power generation and the integration of large amounts of unpredictable intermittent renewable sources. Energy storage can provide manifold values in i) help meeting of peaky large scale electrical loads, ii) providing time varying energy charge management, iii) allowing renewable power generation to be stored to alleviate intermittence, iv) improving power quality/reliability, v) meeting remote load needs, vi) storage for management of distributed power generation, etc. This proposed research programme will focus on the challenging technical and economic issues faced by integrating large grid scale energy storage with the energy network.

Potential Impact:
The scope of our proposed project is very broad and this is reflected in the breadth of beneficiaries. They include:

- Government, policy makers and regulators who are seeking economically and technically viable solutions to the long-term challenges faced by our electricity network which are also socially and environmentally acceptable.

- A wide range of UK industries including electricity generators, network operators, infrastructure maintenance and equipment manufacturers who will benefit from the techno-economic context that our work will provide for energy storage in relation to future grid operation and also the new IP we will produce. Our project partners will have the initial access to the results under the agreement signed between partners.

- Industry and the wider general public who consume electricity (i.e. everyone - both domestic and commercial users) and who will become increasingly reliant on its efficient delivery in the coming decades. They will expect a reliable and consistent supply at a reasonable cost and with minimum impact on climate from greenhouse gas emissions.

- The British Geological Survey work will have direct input to UK geological underground storage resource information and contribute to formulation of energy policy and regulations.

- Other researchers in academia, industry and government, who will be interested in the scientific breakthroughs we make through our unique multi-disciplinary approach. This includes researchers both in the immediately related area of energy storage but also those engaged in the wider energy research field. The models and methodology developed for the whole system and CAES technology study can be shared among the academic community.

- Part of the research work proposed will utilise the data and parameters supplied by the industrial partners, which is very beneficial to the academic community. Results from the scientific and technical research will have direct relevance to the industrial business thereby creating immediate industrial impact.

- The group of researchers who will acquire an array of techno-economic and transferable skills and will therefore be well positioned with prospective employers. During the project, we plan to bring PhD research students to the team to explore the extended topics resulting from the project programme. The PhD researchers will gain experience of working with industry and a multidisciplinary academic team.

- The research findings can be integrated in the teaching contents at undergraduate and master's level across the disciplinary areas from technology, engineering, geology, economics and system sciences.