I don’t currently have a large scale system; I’m currently running my fridge and a few other things off of a portable solar/battery setup, as part of researching a whole home system.

I had already done the research I needed and was ready to put in a larger house-attached grid-tied system slightly before the current generation of portable battery/panel setup came out. For your situation, I agree you are taking the right approach.

I’m on a standard rate plan, I pay 14c/kWh round the clock.

Can I ask if the 14c/KWh is the rate you pay for generation only or the whole cost to deliver 1 KWh to your house (transmission,distriubtion,generation,customer connection plus fees). Put another way, if you consumed 1000KWh in a month would you have exactly a $140 electric bill?

The ToU price and schedule for my region looks like this:

Peak is ~29c/kWh, Off-Peak is ~11c/kWh, Discount is ~7c/kWh. So I could save money if I just switched to the ToU plan and threw my main breaker 3 hours a day.

My local energy company’s exporting solar program is bad and about to get worse, to the point it’s out of the question. I’m not going to sell them power at mid-day for 3c/kWh and buy it back at damn near 30 at night.

Ouch, so even on the fixed rate power plan you essentially 4.67:1 net export (as in you have to export 4 KWh at midday to import 1 KWh any other time of day)?

So the only real winning strategy here is the “ToU + battery time shift” and since the equipment needed to do that almost certainly has plugs for solar power, might as well put up some panels. Buying power at 7c/kWh in the early morning, generating your own power and not buying anything during the day while power is 11c/kWh, and then using the power you bought earlier when it costs 29c/kWh is the move.

Yep, in your state, I agree TOU+battery is likely the best way to go limiting import as much as possible.

Not as useful on a heat pump where you want to generally run the same temp 24/7/365 to give the heat pump the most time to extra energy from the outside air and avoid large temperature swings triggering power hungry electric strip backup heating. A programmable thermostat is still useful for the occasional vacation hold though.

This isn’t congruent with my understanding of how heat pumps work. Electric strips are going to kick on in extreme cold if/when the heat pump can’t keep up, or for defrosting the outdoor unit. Every heat pump I’ve used, unless they frost up, will happily heat a house to 80 degrees from 32 without kicking on the emergency heat until and unless it needs to defrost.

For modern heat pumps your experience is mostly still applicable. The exception is the “comfort” settings most vendor thermostats incorporate. If a temperature increase is indicated by the operator above a certain set point, the system interprets this as a call for rapid heating and will run the condenser at 100% but also kick on electric strips to reach the called for temperature much sooner.

I’ve never personally seen one kick on heat strips simply for increased Delta-T, not without manually putting it in EM-HEAT mode.

I don’t currently own a heat pump, I have an air conditioner and a condensing furnace.

When we bought this house it had natural gas furnace too. Not only was the gas expensive, but during the warmer months the minimum require “connection fee” continued to get hit with price increases even when zero gas was consumed. When we finally replace the heat pump the connection fee was $40/month. My neighbors tell me its risen to $70/month now and none of that money goes toward consumed gas.

My long term plan is to have the air conditioner replaced with a heat pump, and keep the furnace for emergency heat instead of strips.

I considered a dual fuel setup like that, but the economics of the connection fee negated any value. I’ll be the first to say that my January and February electricity bills are very high, but all of the saving from not having natural gas, and being able to heat with solar generated heat pump in the spring and fall very much still make it financially worth it for this setup.

I recently learned that in North Carolina, if a given heat pump system is calculated to keep the home up to a certain temperature on the typical coldest night in the county, backup heat is not legally required. Defrost will be achieved by running the unit in AC mode, so you’ll occasionally get a blast of cold air from the vents.

I can run my heat pump in AC Defrost mode too, but the **Wife Acceptance Factor ** goes way down doing that so we run electric strips for the defrost cycle.

Neither my air conditioner nor my furnace run 24/7/365, both are duty cycle modulated, they turn on and off throughout the day and night to maintain temperature.

Perhaps I wasn’t clear. I wasn’t suggesting my heat pump is running 24/7/365, quite the opposite. Rather, the thermostat is set to a single temperature and, unlike gas heating, there is no value in lowering the thermostat temperature at night or when the house is unoccupied. The opposite exists, when running a heat pump reducing the thermostat temp at night means the heat pump has to run harder and longer in the morning when you want the house back up to temperature. Its less efficient because the limiting factor is the volume of air that can be moved through the outdoor condenser to extract heat from. If the option to save energy is having the house uncomfortably cold for hours everyday, I consider that a failure of an HVAC design. This is, of course, just my opinion though.

I’m three states north of you and we’ve been running on our Cold Climate Heat pump for two winters now without any gas heating. This unit can still extract heat for the house when the outside temperature is -15°F, but its running pretty inefficiently.