Electricity (by alaric)
Since we had to have the house substantially rewired, due to a combination of flood damage and aging wiring, we had the electrician put in changeover switches on the ring main and the main lighting circuit:
They are the two little rotary switches beneath the consumer unit. Each circuit can choose between the mains feed from the grid, or the corresponding IEC inlet at the bottom of the picture, where we can plug the generator in to feed the house from it.
Also, somebody was amazed at my offhand reference to having military surplus lights from a submarine, so here's the photographic evidence:
They came from Bull Electrical