Fox EVO 10-8-H modbus registers

[AdamNewberry]

phew. glad i put in my install date - i was thinking when i first set up, why does it matter!
im actua;;y happy about the overproduction as long as its not drastic..
i use forecast to set charge limits on battery, so doing slightly more from the sun is ok for me..

[evilbunny]

phew. glad i put in my install date - i was thinking when i first set up, why does it matter!

It's used to predict how much the panels have degraded, and why production has reduced over time.

However it's just that, a prediction, and tweaking that alone can better match production with forecasts.

i use forecast to set charge limits on battery, so doing slightly more from the sun is ok for me..

I'm not sure if Solcast does better in Australia because they are/were an Australian company, or that forecast.solar doesn't do as well because the site is European based, but forecast.solar can be all over the place some days, since doing lots of parameter tweaking on Solcast settings, it's pretty close most of the time, but the API limit is very limiting.

[WyndStryke]

You can tweak the panel efficiency in the solcast setup, I think it is set at 90% originally which represents a decade of degradation. Try about 96% for a new installation and see how it performs on a clear day. It's hard to compare it on a cloudy day because it's mostly the clouds which determine that day's production.

[evilbunny]

Looks like degredation defaults are by panel type

Code: Select all

0.0023 (mono-Si)
0.0059 (poly-Si)
0.0095 (a-Si)
0.0030 (CdTe)
0.0002 (CIGS)

I'm pretty sure that for hobbyists accounts, solcast only gives you forecasts in kW, and you then need to turn that 30min guesstimate into a kWh number.

[WyndStryke]

This is what it gives you for hobbyist accounts (this is my west array):

Note you cannot specify the cell technology, only an efficiency factor. Also, it does not seem to take the installation date into account for hobbyist accounts, since if I recall correctly, it was at 90% from the start, and I had to manually set it to 96%.

Regarding the kW to kWh conversion, the Solcast integration on home assistant will do this for you for the overall generation, and the individual array generation.

From what I've seen, in the UK, solcast consistently performs significantly better than forecast.solar.

[evilbunny]

Note you cannot specify the cell technology, only an efficiency factor. Also, it does not seem to take the installation date into account for hobbyist accounts, since if I recall correctly, it was at 90% from the start, and I had to manually set it to 96%.

I had to set our 3kW system to 90% and the 1kW system to 80% to get matching forecasts.

Regarding the kW to kWh conversion, the Solcast integration on home assistant will do this for you for the overall generation, and the individual array generation.

Since I'm using it in a python script I just multiply it by 0.5 for kWh, my comment was making it known that's what you get, that's all.

From what I've seen, in the UK, solcast consistently performs significantly better than forecast.solar.

Just have to tweak the settings properly before that will happen.

[evilbunny]

The Solcast forecast for today suggested that we might get ~20.0kWh for both systems and we've had 19.1kWh with the panels still doing a couple of light bulbs worth of power.

forecast.solar this morning said we'd get ~8kWh, although the forecast did improve as the day went on in subsequent forecasts.

[BOD]

also gents,
fox updated my evo firmware last night - i can now write MaxSOC on grid via the inverter.
the only constraint is that mode scheduler must be disabled (have queried if there is a way for me to toggle that via modbus).
But for me - i was only using mode scheduler for forced charge overnight - now i can set the max SOC on grid, I can default to the older Force Charge periods. Happy days.

Managed to get a full control loop going now!
Checks solar forecast tomorrow - works out a reasonable Max SOC at 7pm and writes it to the register.
Force charge happens in the last 100minutes of the IOGo cheap rate overnight.
To handle IOGo intelligent dispatching, HA checks the dispatch windows, and if car is plugged in - if plugged in, moves zappi from eco+ to fast to enable charge. Limits the battery discharge current to a value that roughly allows only the house load to discharge - to avoid battery drain into the EV.

and created a nice dashboard for that too!

Hi Adam,

I’m currently trying to set up a similar automation, but I haven’t been able to find the entity you mentioned, “MaxSOC on grid.” Should this perhaps be number.min_soc_on_grid instead?

Also, has anyone found a way to force the battery to discharge? I have an export limitation and would like to discharge the battery before recharging it with solar energy, to help minimise clipping.

Another idea I’ve been considering is a method to export all solar energy when my panels are generating below the export limit, and only charge the batteries when generation exceeds the export limit.

I’ve already written automations to divert excess power to charge my car and switch on the immersion heater, but once these no longer require power, the excess energy ends up being clipped.

If anyone has any suggestions or ideas, I’d really appreciate hearing them.

Thanks,
Brian

[AdamNewberry]

Hi Brian. It’s not an entity. It’s via the actions tab in HA. You want to write to register 41010.

[BOD]

Hi Adam,

Thanks for getting back to me so quickly.

Can you share the modbus document you received from Fox. The document vinayrk posted on this thread doesn’t have the register you mentioned.

Thanks

Brian

[AdamNewberry]

Sure, Brian, apologies I missed this message.
Also i just got notice that the pull request was merged to the main branch on the modbus integration on github.
if anyone wants to give it a try!

Cheers
Adam