How to view the excess PV voltage and ultimate amps / watts when batteries are full

[Dinobot248]

Another newbie question.


Is it possible to remotely view the voltage, amps and power coming from your PV array when your batteries are full?

A better way to ask is .... How much energy am I not collecting because my batteries are full?

Another angle is .... How to I optimize my PV energy usage by offloading the extra to air conditioning since I can control that remotely while not pulling too much to drain the battery.

My current system is EG4, 6 Lifepower4 batteries, and 6kw of PV.

I know that viewing pv voltage is easy, but the amps and ultimately watts ( a function of volt sx amps) many not be viewable since the power isn't fully flowing.

 

[OffGridInTheCity]

Solar panels don't push power. They provide (up to their limit) whatever the load asks for - e.g. a Charge Controller is the most common load ones puts on a PV array.

When the battery fills up it means the charge controller(s) don't need any more power from the PV array to do charging. So there's no 'load' (no current flowing) on the PV array - e.g. nothing to measure because nothing is happening.

As far as the theoretical loss of PV power.... you can collect statistics for the days when the PV is maxed out and extrapolate based on this data.

For example, my highest day this year for PV was 87kwhs at prime spring conditions - e.g. almost perfect sun, long day, cooler ambient temps, and full, continuous load during daylight hours where the charge controller was running BULK MPPT all day (e.g. battery never got charged). So I can use this as a baseline to see what I don't get. You have to adjust for less sun as it's less optimal part of the year and for temp changes - e.g. really hot summer days will decrease production significantly.

I use a couple of location specific web sites to understand things better -
PVWatts - https://pvwatts.nrel.gov/pvwatts.php - will show you past history based on your location / weather and is a pretty good guide of what you should get in practical terms.
SunCalc - https://www.suncalc.org/#/40.1789,-3.5156,3/2023.08.22/15:09/1/3 - will show you sun duration, angles, a whole bunch of interesting info.