Edinburgh Napier University

  Wind and solar energy holds a lot of promise when it comes to replace the conventional energy sources such as fossil fuels and coal. However, there is one problem: How do we store solar and wind energy for times where wind doesn’t blow or sun doesn’t shine? In fact, 1.5TWh or 3.2% of wind generation in 2017 was wasted as wind farms in Scotland were turned down or off (called “wind constraint”) due to their output not being able to be used by the market. This costs the UK National Grid of £110 million in 2017 . In China, 42TWh or 14% of wind generation and 7.3TWh or 6% of solar generation were constrained in 2017 due to the similar reason.
A novel compressed air energy storage (CAES) - Aquifer Compressed Air Energy Storage (ACAES) -was proposed in this study. The advantage of ACAES against the conventional CAES is widely available suitable sites. In addition, a higher storage air temperature allowed in aquifers than in a cavern could also potentially improve the energy storage efficiency. The proposed study is to conduct a feasibility study of the new and novel CAES technology, using numerical modelling analyses. This study is to pave the way for future field tests of ACAES technology.