Boiling a kettle is about 3p for a full kettle. It depends how many times you boil it and if you rinse in running water.
if you know your monthly usage on electric you could try it for a month and see if you use more.
So, I rang the shop I wanted to go to repeatedly today, no answer. It rang until the exchange cancelled the call every single time. Drove 30 miles to get to it and they didn't have my size.
Very nice but essentially useless assistant said they must have been busy if no one answered the phone. All morning? really?. I think they've turned the ringer off the phone. Underwear shops aren't exactly groaning with customers, mainly because 50% of the population don't have norks.
I will be complaining. This is why I hate shopping in shops, mail orders much better.
£1 in McDonald's comfort eating.
£2.30 parking to spend 17 minutes in the car park of disappointment.
Brilliant result on your complaint North.