The UK Energy Crisis – Time to prioritise energy storage?
The Status Quo
The UK relies on a diversified supply of energy, from wind, solar, nuclear, natural gas and interconnectors as seen in Figures 1 and 2. Note how the naturally intermittent sources of solar and wind power have grown from 2012 to 2020 to become a major part of the UK energy mix and how natural gas is used to compensate for this intermittency. The UK relies on diversification of energy sources to have a steady supply. However, as seen in the above plot, the UK does not have enough indigenous power and interconnectors with Europe are a key source of energy. In addition, the UK imports 45-70% of its seasonal natural gas supply, primarily via Norway and LNG.
The Status Quo – The problem
1. Impact of the decreasing baseload diversity within the UK Energy Mix
2. Lack of Energy Storage
The decreasing diversity of the energy has come as a result of reducing the use of nuclear and coal power. This brings challenges as coal and nuclear have historically been used as baseload power sources. Their capacity has been replaced by renewables that are back-filled with peaker natural gas power when the wind is not blowing and the sun is not shining. The uptake of baseload renewables, such as geothermal, is not yet widespread in the UK and so there is limited capacity to fall back on.
Undoubtedly, the movement to renewables is a good thing. However, the natural intermittency of solar and wind has created a structural shift from the power sources of the 20th century. Any system must be robust enough to handle days and even weeks of becalmed weather over large areas. Such a system demands incorporation of renewable baseload technologies, or a reserve energy supply to be available whenever renewable levels fall.
In the current UK system, which uses renewables backed by natural gas, there should be a reserve supply of natural gas and renewable energy. The problem is the UK lacks both.
In 2017 the UK’s major gas storage site, Rough, was decommissioned. The UK now has one of the smallest gas storage capacities of the major European economies. Unlike nations such as Australia, the UK has not made major investments in renewable storage technology yet. Furthermore, the UK is years away from diversifying the supply of renewable energy across differing weather pattern regions, in partnership with Europe.
Storage – A need in the Short, Medium and Long Term?
A wide range of options exists to store excess renewable energy, from gravity solutions, to pumped hydro, to batteries to hydrogen. Timescales for implementation of any of these solutions will be a key consideration.
As natural gas will continue to be used to backfill renewable power in the short to medium term, increasing the UK’s natural gas storage capacity may be an imperative. This could help alleviate shocks that will arise from competition for LNG cargos in the short term, and could provide infrastructure to support a blue hydrogen industry in the medium term. Again, timescale for implementation will be a key consideration.