[BlueSkyJaunte]

I keep hearing radio ads about this thing. 99% of my brain keeps screaming "SNAKE OIL!" while the remaining 1% is trying to figure out how to do it on my own.

I did come up with one method--since our power company has a "time of use" plan that we utilize, our electricity costs are lower during off-peak hours. The simple solution would to build a box of batteries that "learns" your usage habits and charges just enough during off-peak hours, while discharging during on-peak. All you would have to do is program in the correct time windows.