Explainers
The device pages answer one appliance each. These answer the questions that sit across all of them — where the numbers come from, and what they leave out.
The wattage on the label is four different things
A television, a fridge, an iron and a kettle all carry a number in watts, and it means something different on each of them. Three of the four cannot be turned into a yearly cost the way every other site does it — and one of them does not depend on the wattage at all.