As someone who installs Tesla batteries I generally agree with u/homeonthemountain. Though I don’t think it’s so black and white. To answer your question though. It’s not the state it’s GMP and VEC. And not actually a deal with Tesla as far as I understand. Both of those utilities have leasing programs that allow people to get batteries at relatively low upfront cost and a low monthly fee. The utilities get to use the batteries as small peaking generators while primarily maintaining them in reserve for use as home backup. They used to only offer the program with tesla batteries more recently they’ve also started allowing Enphase systems as well. Another alternative, though not necessarily as simple, would be a custom system with lead acid or maybe lithium. Those come likely with higher upfront cost and potentially more challenging financing and insurance implications. Not to mention a somewhat more complex system that might need periodic maintenance. Though cost over time could be lower. No doubt though installers push the low upfront cost that is essentially just an installation fee to get people to buy batteries they don’t necessarily need and pay the higher cost over time. All that said there’s plenty more to consider on what kind of battery you get or if you even need one.