To achieve energy self-sufficiency without breaking the bank, the UK could adopt a number of practical measures. Firstly, by enhancing energy efficiency, it could reduce our energy consumption, for example, by insulating buildings, employing energy-efficient technologies and optimizing industrial processes. This would decrease its reliance on imported energy.

Secondly, investing in renewable energy sources such as wind, solar, and hydro power could provide a sustainable and cost-competitive energy supply for the UK. The cost of renewable energy has decreased substantially, so it can now effectively compete with traditional energy sources.

Thirdly, energy storage technologies, such as batteries and pumped hydro, can address the challenge of intermittency associated with renewable energy. Storing excess energy generated during peak periods and releasing it when needed would provide a reliable and consistent energy supply, and reduce the need for imported fossil fuels.

Fourthly, the UK could invest in carbon capture and storage (CCS) technology. CCS technology captures carbon dioxide emissions from power plants and stores them underground. This would help reduce greenhouse gas emissions while still utilizing fossil fuels such as gas derived from hydraulic fracturing until the transition can be made to renewable energy sources. The UK is in a favorable position for CCS owing to its North Sea oil and gas infrastructure.

Fifthly, the UK could play a significant role in facilitating the development and use of synthetic fuels. These can be made using carbon from the atmosphere with hydrogen produced by electrolysis to make methane and other hydrocarbons up to and including aviation fuel in ways that involve no fossil fuels, and which can be engineered to emit water vapour instead of pollutants as their exhaust.

By pursuing these practical measures, the UK could reduce its dependence on imported energy sources, and progress towards self-sufficiency in energy without excessive spending.

Having established that it could be done, the question moves on to one of whether it should be done. The answer to that bears upon whether the UK decides that it needs to be less dependent on fuel obtained from increasingly assertive and aggressive foreign autocracies.