From our perspective it’s been worth the investment. We did a new water heater while the electrician was wiring everything up, and that’s saved us an additional grand (at least) every year not using heating oil. Last time we talked energy prices with the neighbors they were averaging over $500 per month, but we generate enough to bank credits to last us through the winter at the hookup fees.

Granted, our winter heat is primarily the wood stove and a low consumption floor fan to circulate the air and not space heaters, but our overall ROI is below 10 years given heating and electricity costs in our area.