I don’t think that’s it. I’ll speak to California since that’s where I live. Most people live on the coast where AC usage is not high and most furnaces run on gas, not electricity. So I don’t think this explains a lack of battery uptake in the Northeast. There is still a lot of demand for electricity, it’s just being met by other sources.

Edit: I looked it up an CA has one of the lowest per capita electricity rates in the country: https://greeninnovationindex.org/2025-edition/energy-efficiency/figure-52/