Liquid air is about storing cold and power produced by renewables to use in a vehicle. This cuts diesel consumption, emissions and cost. The only exhaust is cold air.
When people talk about energy storage they usually mean electrochemical batteries. But when the service required is cooling, and especially when ambient temperatures are high, it is often more effective to store energy as cold. Liquid air is a powerful new energy vector to provide distributed clean cold and power in vehicles and buildings.
Key to renewables replacing fossil fuels with an alternative fuel in transport is how to store the energy that is produced so that we can use it when it is needed in transport applications for example batteries or hydrogen.
Liquefying air is the cornerstone of the industrial gas industry (liquid nitrogen, oxygen, etc) – but it has only recently been seen as a pioneering solution to the problem of energy storage; capturing surplus renewable energy to use on demand in grid or transport applications like the Dearman-Hubbard Transport Refrigeration System.
Air turns into a liquid when cooled to around -196ºC using standard industrial equipment.
This process can be driven by renewable or wrong-time/off-peak energy. 710 litres of ambient air becomes about 1 litre (0.26 US Gallon) of liquid air, which can be stored in an unpressurised, insulated vessel.
When ambient or low grade waste heat is reintroduced to liquid air it boils and turns back into a gas, expanding 710 times in volume. This can be used to drive an engine. It also exhausts lots of cold, making it highly relevant for processes which require power and cooling.
Liquid air is now recognised as a potentially powerful new energy vector, offering a new sustainable approach.
“Utilisation of liquid nitrogen for both refrigeration and power is an exciting concept, especially for transport applications. The technology can provide not only potential savings in fuel consumption and emissions, but also better cold chain temperature control and stability.”
Jon Trembley | COE Lead Cryogenic Applications, Air Products
Dearman zero emission Transport Refrigeration
The Dearman Transport Refrigeration Unit is the first to meet all environmental challenges – and set new industry performance standards – all without having to compromise on cost.