Quote Originally Posted by Khendraja'aro View Post
I'm not entirely sure that heating water is one of those things which have an efficiency of scale. Using electrical energy to heat water is pretty efficient at any size. It's the other way (read: converting heat into electrical power) which poses the problems.
Which is why it's pretty inefficient, since you have to create the energy first I'm also not too sure about economy of scale, IIRC modern boilers are very efficient already anyway.