I have a Quooker tap, and no kettle. It's a game changer in the kitchen, need boiling water for cooking and it's instantly available, and my wife can have tea in a second whenever she wants, no waiting around or boiling a certain amount in the kettle, also one less appliance on the counter-top.

The energy usage is indeed minimal; I've measured it with a power meter over a couple of months and barely used a fraction of a kWh.

There are other boiling water taps, but Quooker is incredibly well built, really simple, and was created in an era of making things to last, it's got a price tag to match, but well worth it in our households opinion.