Along those lines, I don’t understand why there don’t seem to be thermal storage head units for heat pumps. Cheaper and more effective than batteries, at least for storing heat, plus less noise and expense as the system doesn’t have to come on as often.

Why doesn’t everyone doing solar or with time of use metering have these? Online I only found one example and it was only available in Canada

My parents had thermal storage electrical heat with time of use metering and it made a huge difference on their electrics bill. Seems like it would apply to heat pumps as well