Spotted a similar device on MAPLIN, called a N67FU Power Cost Meter, which seems to work nicely. For the whole of July it was on the freezer and that cost us £2.68 to run in very warm weather (freezer is in the shed) - I'll try it again in January for a month. Just now it is on the kettle for a month. I'd say it takes 60 to 90 watts to boil water for two teas. The objective is to get that below 50 watts. -- muymalestado