Whether driving a car, switching on a light, or turning up the heating – we take it for granted that there'll be sufficient energy for us to use at that very moment. But this only works if two basics are in place. Firstly, energy needs to be transported quickly and reliably to the consumer in the required form. Second, energy storage guarantees straightforward access and acts as an 'energy buffer' to fill the gaps in distribution. So, what kinds of storage do we get our everyday energy from?