House batteries are never purchased in isolation. They're what amounts to a luxury add-on to a much bigger solar system, so you'd expect to see a "markup". That may change with the recent rollback of net metering in CA, which is making a battery system a requirement to reach break even on cost.
> That may change with the recent rollback of net metering in CA, which is making a battery system a requirement to reach break even on cost.
NEM3.0 doesn't make a battery a requirement to break even on costs, it just extends the payback time of solar without batteries by 3-5 years. It reduces the still absurdly long payback time of home battery storage somewhat, though. Only when you can sell power back to the grid with batteries at peak wholesale rates will batteries have anything like solar's payback time.
I've seen a lot of different numbers thrown around (and to be clear: I'm in Oregon and not part of the fight). Let it suffice that NEM3.0 makes the relative benefits of a battery for time shifting (and thus the costs of a solar system without a battery, as was typical for early installations) much, much higher.
I guess it depends on the rate structure you have. Higher rate variance between off and on peak periods definitely helps with the economic case for batteries, since it offers an arbitrage opportunity.
I haven't done the math yet to figure out how that variance relates to payback time for batteries, but would be a fun exercise.
