Electrical Question

My neighbor was at the local home show and he came across this product which appears to be a voltage regulator and a capacitor. The companies claim is you recieve the power from the power company @ 118 volts and the extra 8 volts is being released as heat, they say thier product stores this 8 volts of power for use at a later time. He paid $500 for it and with some kick backs from the power company and govt. it will offset but I was questioning if this was a scam or not