Hi Dexter2328,
Thank you for your inquiry.
The tank's insulation is composed of a thick, heat resistant Styrofoam that both maintains the desired water temperature in the tank and helps to prevent the plastic casing from getting hot (it will be warm to the touch).
As for your inquiry about our hot water dispenser’s energy consumption, below is a link to its energy usage analysis.
http://insinkerator.custhelp.com/ci...For more inquiries, please do not hesitate to contact us through insinkeratorfeedback@emerson.com or call InSinkErator AnswerLine at 1 (800) 558-5700.
Thank you!
Jerica
InSinkErator® Customer Service