6kW+ from a 5kW inverter?

pad406

I've noticed a few times that if my battery needs charging the system doesn't seem to be clipping at 5kW but producing more (I have 7.2kWP panels). But once the battery is charged then the clipping starts. 2 samples below:

The inverter is a Solis S5-EH1P5K-L.

Is it clever enough to do that?

And if so, the big question, can I 'make' it do it for the EDI? So rather than wasting the excess generation can I push it to the EDI but ONLY if it's greater than the 5kW? I don't need hot water all day, but if I can still export and heat the EDI then happy days.

Or is the graph just lying to me :(

slave1

you can set device export limit on your master myenergi product at 5000w so then it will only divert PV above 5kW to the EDDI

graememk

https://www.boards.ie/discussion/2058351057/6kw-from-a-5kw-inverter

What your asking, short answer is no

Only 5kW can leave the inverter, when the battery is charging the power isn't leaving the inverter.

A way around it is build automation to possibly control how fast the battery chargers eg put 2kW into the battery and 5 to AC. But it's on the advanced side and requires modbus control of the battery or the inverter.

You possibly could manually limit the charge rate in the solis inverter settings but it wouldn't be dynamic

soram

Hi, I would like to add to this. I am seeing the same but this was not the case last year. I have a 6kW Solis and 7.9kW of array and last year my inverter would happily produce more than 6kW even up to 7kW for hours in Summer. I know this because often my backflow exceeded the 6kW. The Solis portal graph used to have a dotted line indicating 20% (I think) above rated capacity. The inverter died this January and was replaced like for like but now I am seeing exactly what the OP is seeing. As soon as my battery is charged the Inverter output clips at 6kW. So basically the backflow feature in now redundant as the inverter itself will never produce more than 6kW and my house load will eat into that.

This has to be a firmware feature. So either it is in the firmware now or is part of the 'Standard' that is chosen e.g. ENXXXXX.

I will probably submit a ticket with Solis just to understand what has changed.

ian123

The EDDI option is based on AC not DC, so if the inverter is already hitting its 5kW AC limit, as far as I can tell the EDDI cannot be utilised - there is no "excess AC". The inverter can divert DC power to the battery while also doing it's 5kW AC thing, so anything above 5kW from the panels can be used for that. I saw that with my own 5kW inverter where the batteries were about 50% charged and I had a full 5kW load in the house - for the 1st time I saw 7.5kW of power generated - 5kW going to AC (inverter limit) and another 2.5kW DC going to charge battery. that's a 50% jump in power generated.

Once the battery was full, even though the panels had the capacity to hit 7.5kW (as it remained sunny), the system was clipping at 5kW.

What I need is an additional load on the DC. Once the battery is full there is no additional DC demand. As you mentioned the EDDI - I cannot understand why a solution of using the inverter DC output to charge a battery and drive a DC EDDI as the same time does not appear to exist. This approach would help with clipping as long as there was DC demend (ie a battery to be charged, or a DC EDDI heating water).

Maybe a sophisticated battery management solution that could daisy chain the DC out to a DC EDDI could be considered. Does such a thing exist?

soram

Again, but this was not the case in the past. Unfortunately I don't have the Solis log from last year as I stupidly deleted the old inverter from my account but this is my HA log clearly showing hours of 6.7kW production with no clipping and no battery charging.

graememk

https://www.boards.ie/discussion/comment/122119403#Comment_122119403

A inverter shouldn't output more on AC than it's rated to do (even if it can). Could have been a bug in the firmware of your old one...

I've never seen my 6kW solis string inverter pass 6kW.

soram

https://www.boards.ie/discussion/comment/122119653#Comment_122119653

I agree. But as I said they used to and used to be all right with that. They even had that dotted line at 20% above rated capacity on the graph. I have never seen my inverter clip until now. My older firmware was updated many times over the year for other reasons so can't think it was a bug in just mine. Maybe a bug in general that is now resolved. I realise I don't have a leg to stand on but it was nice to be able to 'sometimes' take advantage of the extra production capacity of the array if consuming it in the house but limiting the export to 6kW with the backflow parameter.

pad406

Thanks all, makes sense now, hadn't thought of the DC/AC issue.