[gmaslov]

This idea might be up there with saving on your electric bill by installing little turbines on all your water faucets.

[stcredzero]

For awhile you could buy a natural gas burning Stirling engine that would provide electricity while heating your water with the waste heat.

[ricardobeat]

The idea here is that you "bring free energy home" from Tesla's solar-panel-powered stations (leaving you car battery empty), not that you get to use it twice.