GETTY
Many of us will remember as children reading by torchlight under the bedclothes and, later, by candlelight (but not under the bedclothes!) during the power cuts of the 1970s.
But today, usable lighting that doesn’t need to be plugged into the mains is widely available. This is thanks to a combination of batteries that last almost indefinitely and are also often rechargeable along with, more significantly, LED (light-emitting diode) bulbs that use a tiny fraction of the power of old-style tungsten bulbs without producing any appreciable heat.