I have one but it is small. Not enough to power the entire house. Also, there are associated maintenance costs and fueling hassles. We cannot store much gas or propane in our homes.how about a generator?
And, the TEG and Powerwalls can be used every day to reduce the amount of money we send PG&E monthly. And this is something I try to do as much as possible. Nothing brings a smile to my face like seeing my PG&E bill shrink.