It’s simple. Ten minutes before you plan to bathe, you flip a switch. The light comes on and the water heats up. You wash. You turn the switch off. Geysers, as these small almost-instantaneous-but-not-quite hot water heaters are called in India, are so smart. I don’t keep a kettle simmering all day so that when the urge for a cup of tea strikes, I can have it instantly. (btw, for my tea at home, I use this, one of the best Christmas presents I ever received.) Same idea. Yet this is how we heat water in American homes. It’s the second largest energy expense in the average home, typically accounting for about 18% of the utility bill.
This one in the guest house where I’m staying is particularly cheerful.