An instant drop of 15%!!! I received the unit today and hooked it up in 20 min. I installed an amp meter on each of my main utility legs. Here is my readings of both 120 volt legs added together 40.7 amps with the electric saver turned off. 34.55 amps with it turned on. That is an instant drop of 6.15 amps. 6.15/40.7= 15%. I turned it on and off several times and the results were the same. 6.15 amps times 120 volts is 676.5 watts 24 hours a day. This computes to 486 kw in a month, and at 9 cents a kw, my monthly savings will be $43.74 x 25 years product life= $13,122 return on my investment. Needless to say, i am very pleased.