What is 'loads' and how can I measure actual house consumption?

[PeterDujan]

Hi, I am trying to understand my real house consumption in Home Assistant.

Is there a sensor in foxess-ha that shows actual house consumption / total load for the home?

I am confused about the difference between:

• load_power
• loads
• gridConsumption
• PVEnergyTotal
• battery charge/discharge values

What I want is the simplest possible number for:
“how much electricity the house actually used”

For example:

• if the house uses solar, I want that included
• if the house uses battery, I want that included
• if the house imports from grid, I want that included
• if energy is exported to the grid, I do not want that counted as house use

Is load_power the correct sensor for that?
And is monthly loads the energy version of the same thing?

If not, what sensor or formula should I use to measure true whole-home consumption?

I'm pretty sure my power company is doing something dodgy, as their usage and what FoxESS is reporting as my total usage seems way too high.

Cheers.

[FozzieUK]

Just a few assumptions to start, if you have a hybrid inverter (H,KH,H3) and your system is wired correctly, it doesn’t have any second solar inverter that isn’t being monitored by CT2 (meter2) then ‘loads’ or sensor.foxess_load as the integration presents it - is the cumulative daily load (all house load) consumed within your house in kWH.

load_power is the current load power being measured in kW (based on the 5 minute samples) - if you were to convert this via an integral (Riemann sum) the daily total would be the same as ‘loads’

Gridconsumption is the daily grid consumption in kWh

PVEnergyTotal is the daily total for all solar panels attached to the inverters PV strings in kWh

Battery Charge /Discharge are the daily energy totals for each, Charge/Discharge Power is the present value in kW - again if you pass these through a Riemann sum to convert to kWh they would be the same as the energy totals.

So the short answer is that ‘loads’ or sensor.foxess_load is the daily load in kWh used within your house.

[PeterDujan]

Thank you so much for taking the time to answer.

Just to confirm the exact boundary of loads / load_power:
Does sensor.foxess_load include any inverter/system self-consumption, or is it only electricity used by actual household loads/appliances?
For example, if the inverter is using power for its own operation, battery management, communications, etc, is that included in:

• load_power
• loads

Also, is it fair to say that sensor.foxess_load is the best built-in FoxESS sensor for true whole-home consumption in HA?
I’m trying to understand whether it represents household usage only or household usage plus inverter/system overhead.

There is a bit of a story as to why these numbers are important. But I am not convinced my house is using the energy that FoxESS is reporting I am actually using. It looks to me as there is a lot of electricity being used that is not consumption from my household.

Cheers.

[FozzieUK]

The system usage isn’t the easiest question to answer as it depends on inverter and firmware version (Fox have changed this a few times) - it used to be in the house load but in latest gen inverters / latest firmware appears to have been moved.

You can approximately calculate the real time system losses using this formula

    Losses = PV(1/2/3/4)_power + grid_consumption_power + bat_discharge_power - bat_charge_power - feed_in_power - load_power

That said, it’s not a very large number which will be bigger on larger (or 3 phase) inverters but still is typically in the order of 50-100 watts per hour.

However for your energy supplier you have the 2 important metrics there, your grid consumption and your export (feedin) which should be close with what the meter says.

But just to mention, CT clamps are not very accurate typically 1%-5% depending on measured load (they get worse at lower powers) and they can be affected if they are in close proximity to other CT clamps or magnetic sources.

For my house usage I find my grid_consumption sensor measures approx 5% down on what the meter reports daily.

Naturally all of this is complicated by 3 phase power (if you have that), as you can export and import at the same time simultaneously on different phases and in balanced mode (the default) the inverter assumes you will have net metering with your supplier i.e. if you export 1kW and import 2kW you will be billed for (2-1=1kW)

Probably complicated that enough now, but all important things to consider - maybe the easiest way to verify is to buy a wireless CT clamp (like a Shelly) that reports independently and see if that agrees with Fox or your supplier.

[PeterDujan]

Thank you so much FozzieUK.

I am in a bit of a unique situation with my energy supplier as I have an allocation of energy each month. If I stay under the allocation, I don't pay anything ( not even supply ). Going over 3 times ends the contract. All energy consumed is considered usage, regardless of if it came from the grid, solar or battery. So I am trying to get the figures right because even going over my allocation by 1kWh is considered a strike, and I am not too happy they are ( what looks to be ) considering all losses and inverter energy costs as part of my usage.

Thanks again for the help :)