Basic principle of hydrogen economy is transportation and storage of energy in the form of liquid or gaseous hydrogen

Basic principle of hydrogen economy is transportation and storage of energy in the form of liquid or gaseous hydrogen. Which property of hydrogen may be useful for this purpose ? Support your answer with the chemical equation if required.

Hydrogen is a gas at room temperature. Because of its bulk, it is difficult to transport it either by rail or by road. However, by cooling and applying high pressure, gaseous ${ H }{ 2 }$ can be converted into liquid
${ H }
{ 2 }$ which has much smaller volume and hence, can be transporated easily.
Thus, the basic property of hydrogen which is useful for hydrogen economy is that it can be converted into a liquid - by cooling under high pressure.