Precursor to setting up Solar Assistant automations for SunSynk inverters

[klondike]

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Aims of the Automations

My aim was to produce simple Solar Assistant automations that will make use of the Solar forecast (currently only in the Beta software) to top up the battery during the overnight cheap slot such that the power imported along with energy from the solar panels leaves the battery fully charged to maximise the high return export starting a 4pm through to 7pm. That requires some knowledge of your system. If you have not read  Precursor to setting up Solar Assistant automations for SunSynk inverters already I suggest that you start with that.

Adding an Automation

In the Solar Assistant GUI click the Power tab



At the bottom of the page there is a Button named + Add Automation



Clicking that brings up



Clicking Rule Table results in a dropdown list of automations and with each permitting up to two selections for when the selected action takes place.



There are a number of limitations which you will come across with this which can be frustrating as are the "helpful" changes entering a value somewhere will cause in other fields - especially if you make a typo.

The Work Mode timer

This is the set of time slots and options present on the SunSynk LCD screen. Missing from this is the Solar export when battery full which I assume everyone would want once their DNO is issued. I have included it in my set of automations to ensure it is always set on.


This shows another limitation of Solar Assistant albeit just an irritating one for me. You cannot, so far as I can see, give automations a useful name nor can you reorder them. Because of the inability to add lines in the middle of an automation and the way it so "helpfully" messes with whatever is already there as you amend fields it is sometimes easier to start from scratch using the original as your template then add the new and delete the old. This means that any related automations may not remain together and they cannot be combined either.

After that diversion back to The Work Mode timer

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Use timer is checked and I never alter that although it can be changed in an automation.

Each of those timeslots has a number from 1 to 6 which will be needed in some automations in addition to the Time of Day specified in the automation.

Line 1 - this is simply there because I have seen in many reports that you should start with 00:00 as running through from line 6 to line 1 may lead to problems. So I just started with 00:00

Line 2 - this is the Octopus Flux cheap charge period

Line 3 - just a filler to..

Line 4 - Octopus have started offering free use hours usually from 2 til 3

Line 5 - just a filler to 19:00

Line 6 - another filler through to midnight.

SunSynk has no forced export through its GUI and the Workmode controls have no need of specific slots.

Should you choose (usually because you have messed up an automation) you can edit this as if you were using the inverter GUI

Power I left to default. State of Charge are all set to the maximum discharge value of 20%. You could scrape a little extra usable capacity from the battery by lowering this in the Inverter Configuration but at the risk of shortening the battery working life which I don't consider a good idea. None of the charge boxes are ticked.

Cheap Rate overnight import

This assumes that by 2am your battery state will be at or slightly over the minimum discharge level. That is achieved by the preceding day's export and will be explained there.

The automation is done in two individual automations and mirrors how it would be achieved through the inverter LCD screen GUI.

First set what level the battery should be charged to based on the solar forecast such that you reach the Export time of 16:00 or if you choose as I do a little later provided you can export from 100% down to your expected level to last from the end of your export round til the 2:00am cheap charge rate. This is unlikely to work out precisely. I tend to err on having a little energy in hand rather than run out and import at day rate. It's swings and roundabouts so long as you are not really wide of the mark and in any event solar forecasts aren't perfect by any means. You will need to tinker with the figures for sure.



I kept this simple at straight 2 through 5 regardless of how long the charge will take. Your house load will be satisfied for the whole of that period from the grid. This is no bad thing. It is all at the cheap rate. By not taking energy from the battery you have saved the unavoidable double conversion loss and marginally extended the battery lifetime (maybe).

Note that this is setting capacity for Slot 2. You will need to adjust this if you are not using Slot 2.
I know the forecast updates hourly so I set this for 02:05 to get the latest forecast in the event it changes on the hour.

I reset capacity to 20% at the end. Not strictly necessary but I felt tidier.

I always provide a two minute slot for such a change. When I just set it to the same time I saw it fail. I have occasionally seen errors reported that the inverter did not respond...

[Thu Sep 04 05:00:13] Failed to set Capacity point 2 to 20: No response

I also usually leave gaps between lines that could logically just follow...

[Sat Sep 06 13:03:14] Active table row changed twice in 15m00s. Suspending rule table automation for 10m00s. Consider adding a gap between table row end and next row start.

The minimum left may need seasonal modification but it is possible that it will turn out to be self adjusting at least in part - if it is a high solar day there is every chance that the rays will start filling house load early on.

Next set the inverter importing This has to be a separate automation because of Solar assistant limitations




Forced Export at  high export rate



A couple of notes.
The two lines at 13:00 doing nothing at the time of this screen dump are for the free energy days and would be manually changed to start a forced export in the event that the battery had no room to take a charge in the hour of free energy usually from 14:00 to 15:00. It's hardly worth the effort as the only gain is a few kwh of modest value export plus whatever extra use of home load you make

Again I run the automation to potentially run the entire slot. I have tinkered with the solar export rate to make sure the inverter can export from full down to my desired endpoint of 45% designed to last through to 2:00am.  This is setting is covered in  https://letschat.club/index.php?topic=6087.0

I ensure that Zero Export gets set at the end of the high rate export period even if it didn't complete in time.

Worth noting for all these automations is that green Enable shows that at the time of the screenshot that automation is NOT enabled. Clicking it will enable it. When you have finished editing any automations scan through to ensure that everything you want to run is showing a pink Disable and ones you don't want to run are green Enable.

Inverter longevity and efficiency.

Check under the Charts tab

 

You will find one for the Inverter Temperature and see that it shoots up during import and forced export. High temperatures both reduce efficiency and potentially the inverter lifetime. For that reason I have set my Grid Charge Rate and Solar Export Rate at the lowest levels needed to complete those functions within the three hour time slots. I am also in the process of adding a couple of 120mm PC type fans above the inverter heats sinks on a timer to cover each period. I did notice that the temperature rise graph showed a curved rise and sometimes a double peaked top when the temperature rose above the green area. I hope the fans improve on these earlier charts.



Octopus free energy days

These two automations charge the battery on free energy days. Note they use Slot 4


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