It depends whether you’re considering over time or instantaneously. If it’s instantaneously then it’s anything that’s got anything to do with heating or has an electric motor in it. If you’ve got an electric cooker, that’s a pig. Seriously, you can’t put a cooker on a 13A plug. You can’t even put them on a ring. You have to have a dedicated unit with a switch that goes back to the fuse box and some are rated for 30A, some for 45A and I’ve even seen ones that need 65A. The wiring needed for that is really thick and expensive. I’ve sent electricians out and they’ve found that the customer has bought the wrong cooker for their units and so he won’t fit them. Despite the fact we put in big letters what the ratings need to be, and usually asked them if they’re sure that their system can handle it, they did insist on it being my fault. Not likely. Get an electrician in to do the wiring, Mrs bloody Wilkinson, because if you failed to mention that your wiring’s too weedy for it you ain’t getting your money back. If you’re pleasant about it, we might arrange an electrician for you at cost, if not you’re on your own, got it? And don’t think that your cousin Jack, who is a builder, can do this unless he’s got his certificates and competencies to do it, either, because if he doesn’t do it right your collection of bloody Chinese figurines will not withstand the ensuing inferno, alright?
Big cookers are hogs. So is the kettle. But a kettle is only working for three minutes or so a go, and so unless you drink tea like there’s no tomorrow, it’s not that much over a course of twenty-four hours.
Got an immersion heater? That’s a pig too, because water needs a lot of energy to heat it. It takes 4,200 Joules per kilogram per degree centigrade. Now obviously we don’t want any truck with the stupid metric system, which was started by revolting French peasants, and so in proper measures a kilogram of water is about what you’d get in one and three quarter pints.
Washing machines have a heater and a big electric motor and so they’re quite juice-hungry, too, and microwaves gobble a bit.
In short then, if something is heaty or spinny, that’s what’s going to be bashing your bills up.