Storing energy thanks to cryocooled air

A new type of energy-storage process that can operate on a large scale.
Highview Power Storage, a UK-based company has developed a process that uses liquefied air or liquefied nitrogen (which makes up 78% of air) as a means to store energy.
After the carbon dioxide, water vapour and particulate matter are extracted from the air, the latter is then super-cooled to cryogenic temperatures then liquefied and stored in massive vacuum flasks. When the substance is heated, it returns to a gas state generating enough force to drive turbines that generate electricity.
As an energy-storage process, it is comparatively much less efficient than batteries, but it can operate on a much larger scale, as large amounts of air can be stored in this way.
It is also environmentally friendly in its operation, as wind and solar energy are used to suck the air into the compressors.
The process can also be used to extract energy from biomass, industrial or utility plants and deliver cold air – air conditioning, data-centre cooling or refrigeration.
A 300 kW pilot installation already exists in Slough, UK since 2010, and based on its success, the company is now looking toward a 10-Megawatt (MW) commercial scale demonstration at a cost of USD 900-1800 per kW.
In comparison, the capital cost of a high-density NaS battery is 3100-3300 kW per kW, according to Highview.