Check out this BNEF Article. Home battery sales are set to quadruple in California in 2020!
It's most likely the perceived need for backup power that is driving this in a state where high grid volatility is the norm. More residential storage means a greater ability to get clean energy flowing though - how can we incentivize this in places where volatility isn't a driving factor? Rebates are one approach but has anyone else heard of or thought about others?