Hawaiian Electric rates highest in nation

[gtill]

I'm pretty sure it has been banned for water heating, I should have made it clearer. Also, isn't a contractor necessary for any work on your wiring or pipes, certainly would be if adding a bathroom, what's the difference between an addition and a splice into your system, pipe or wire.
Also does anyone know if a seperate 12V wiring system would be legal in your house, stand alone type, with battery backup?