[toast0]

This is possible, and I suspect it will happen if it's not already. Of course, the more it happens, the less profitable it becomes.

The thing is though, this type of thing only really works if you have sufficient interconnection and are paying / recieving the market rate. You've got to have a pretty big system to get to interconnect at market rates. Home based tarrifs aren't going to cut it, because those are usually not refundable, at best your cost goes to zero, which probably doesn't justify your investment in batteries.

Now, if you were putting in batteries anyway, there may be peak shaving options in the controller to charge off peak and discharge on peak. May as well use some of the capacity you installed for redundancy on a regular basis to reduce your energy costs. Especially if you have other generation options. Maybe peak shave down to 60% capacity, if the remaining 40% still covers your use for several hours and you have a generator you can run when you hit 20%. Or if you have solar, peak shave down to whatever leaves you enough power to make it to the next sunny day (or just the next day if you're feeling lucky)