According to the Institution of Mechanical Engineers, turning air into liquid could provide an answer as to how we could store energy, the BBC reports. IMechE has said that 'liquid air' can compete with batteries and hydrogen to store unused energy generated from renewable sources. Electricity produced by wind farms at night, for example, can be used to cool air down to a cryogenic state at a 'distant location' - and when energy demand increases, the air can be warmed to drive a turbine. The process to produce 'right-time electricity', engineers have said, can reach efficiency levels of up to 70%. How the process works
- 'Wrong-time electricity' is used to collect air, strip away the carbon dioxide and water vapour.
- The air left over, which is predominately nitrogen, is cooled to -190C and becomes a liquid.
- The 'liquid air' is then placed in a large vacuum flask until it is required.
- When the demand for electricity increases, the liquid air is warmed to an 'ambient temperature'. As it evaporates, it is used to drive a turbine to produce electricity.