I have a grid meter on the grid feed in and I split my DB between critical and non critical loads. From what I see, ESS doesn't distinguish between PV DC and Battery DC and will power all loads from DC power available.
I would like the option to feed excess PV into the non critical loads, but not drain the bank when powering those loads, in effect prioritising the grid above the battery for non critical loads. I don't think this is currently possible?
It's kind of possible, but might require some rewiring and has some compromise.
The easiest way is to just make the non-critical loads invisible to the Victron system (putting them on the grid side of the energy meter before the Victron system).
BUT I presume you still want to see them, just not discharge the battery to run them.
If you move the placement of the grid meter to only be in front of the loads, and not between the Victron system and grid, then you can reconfigure the Energy Meter to be AC Load meter mode (rather than grid meter mode).
Note this a new feature, and while supported on the GX device since v2.80, is not yet fully implemented in VRM, and not extensively documented. I am happy to help on this side of things, because your questions and answers will help me to expand the documentation.
Things to note - if you are NOT exporting solar, then the curtailed extra solar production will no longer provide for the non-critical loads either (it used to). If you are exporting solar, then it will continue to provide for those non-critical loads when export is available (though will prioritise powering the essential loads and charging the battery first before export/non-essential).
Also note - though it should not need to be said, anything to do with AC energy meters is quite dangerous work as it is interfacing with a grid switchboard which can be confusing and potentially difficult to completely and safely isolate. So even once known what needs to be done, the work itself must be done by a qualified electrician.
Much appreciated, but I don't think it will accomplish what I am targeting. The main idea is to export excess PV to power those loads, but not drain the battery bank.So if the battery is full and there is say 5kw excess PV available and you are trying to power a 7kw load, it should use the 5kw and draw 2kw from the grid instead of the battery bank.
@Mcwidowmaker What you requested here makes a lot of sense and I wonder if you have ever found a solution to only use excess PV for non-critical loads and not battery.
Batteries are expensive. I have a small 48v 100 Ah battery and I want to use it for critical loads.
This is not possible with default configuration of ESS but you can do it using NodeRed on the GX.
You need to change the ESS mode, from Grid meter to Inverter and then set the Overvoltage Feed-In Max to the amount being used by the grid meter. This will not export from your property but will cover all your loads if you have enough PV.
I haven't found a solution yet, but I will have a look at this. I am also toying with home assistant at the moment, although I am still hesitant to allow it to write to the GX device until further testing.
