Last I heard they were taking/giving one for one. Not sure about any net excess you put out.
Its all pretty assinine because the days solar puts out the most are the days the so cal grid has problems keeping up with demand.
Car banks need to be able to go 200 miles between charges to be "viable".
But the vast majority of people travel less than 50 miles a day.
So a substantial amount of energy just sits there.
Set a limit and throw a switch and the grid can use that excess.
Google has an experimental program that provides load levelling from the banks in its fleet.
This crap is the 21st centuries version of snake oil/radium...
What the industry is waiting for is a Henry Ford to step forward with a way to mass produce the panels at a cost the working man will folk to. PV technology is advancing as time and demand march on. Paints, sheets, films that greatly reduce cost to both make and maintain. I remember the first demand switching unit i saw- big tubes and a lot of heat. Now a small panel holds the entire system and you never hear it or even think about it.
Ya remind me of a scene out of an old movie- two old farts sitting in a wagon as a horseless carriage goes poppin' and a-hoppin' on by- "why you'll never catch me in one of those!"