Solar input drops when batteries are connected.

[johnp71]

Hello everyone,

I have been using a 6kw array with a Solis single phase inverter since June 22. (Solis RHI-6K-48ES-5G).

There was an issue with the installation whereby the batteries would not charge, 3 * Pure drive (II) 5kwH batteries.

Turns out the inverter was at fault, the inverter was replaced on Monday with a new Solis S5-EH1-P6K-L.

The batteries are configured as "self use" with "grid charging" disabled.

I've noticed that when the batteries are connected, and able to charge from the solar panels, the incoming solar energy drops by around half, i.e. if the incoming panels were registering 3.0kw on the app, when the batteries are connected, this value drops to around 1.5kw (repeatable and fairly linear), has anyone else had this experience, thought it may be the incoming DC feeding directly to the batteries, however I'd have thought the incoming value would have stayed at 3.0kw, and have shown some of that energy going to the batteries.

The energy for the day reports as this much lower value (i.e. 4kw rather than 8kw)

Thanks.

 

[12VoltInstalls]

if the incoming panels were registering 3.0kw on the app, when the batteries are connected, this value drops to around 1.5kw

I don’t know your equipment but two things that occur to me are:
1) is this a system capable of battery-less operation? What is drawing 3kW continuously?
Without batteries is it delivering 3kW to loads? Operating battery-less? Does it do that? Because could it be then either putting 1500W into the batteries and putting 1.5kW to the loads, or… how does 1500W disappear? There has to be a load to make 3kW happen.

noticed that when the batteries are connected, and able to charge from the solar panels, the incoming solar energy drops by around half

2) So is this gridtie? And configured SBU? So batteries start supplying 1.5kW?

Something is missing here. Could be the lack of contextual information, or could be my ignorance.

 

[johnp71]

hello 12v and thanks for the reply, for clarity this isn't the load side of the system, it's generation only, So, I can be generating 3.0kw from the solar panels, and when I connect the batteries, this generation figure drops (within 1 minute to c. 1.5kw) remove the battery connection and the solar generation goes back up to c. 3.0kw.. not load dependent, only solar generation, which dose not seem right to me, J.

 

[12VoltInstalls]

isn't the load side of the system, it's generation only, So, I can be generating 3.0kw from the solar panels, and when I connect the batteries, this generation figure drops (within 1 minute to c. 1.5kw) remove the battery connection and the solar generation goes back up to c. 3.0kw.. not load dependent, only solar generation

What is the load?

 

[shavermcspud]

What is the load?

The load isn't important, this is a grid tie inverter, the same unit I have here, any excess from PV goes to grid so the OP doesn't have a constant load like you think. To the OP, I would double check your Modbus meter that should be installed with the CT clamp at the incoming mains supply around the L1 conductor, misconfiguration here will show the results you are getting.

 

[Leeds]

"So, I can be generating 3.0kw from the solar panels, and when I connect the batteries, this generation figure drops "

If you have no load then you are generating zero power until you hook up the battery. If you're not putting it into a load then you are not harvesting it at all.

Edit: Unless I'm missing what you mean here:

"The batteries are configured as "self use" with "grid charging" disabled."

Are you saying you are allowing the system to export to the grid or not?

 

[johnp71]

"So, I can be generating 3.0kw from the solar panels, and when I connect the batteries, this generation figure drops "

If you have no load then you are generating zero power until you hook up the battery. If you're not putting it into a load then you are not harvesting it at all.

Edit: Unless I'm missing what you mean here:

"The batteries are configured as "self use" with "grid charging" disabled."

Are you saying you are allowing the system to export to the grid or not?

Hi , I'm not allowing the batteries to charge from the grid, only from Solar power, load is irrelevant in this case as it happens on load and off. (i.e. when the house is using power, or not) thanks.. I'll perhaps post a picture.

 

[johnp71]

The load isn't important, this is a grid tie inverter, the same unit I have here, any excess from PV goes to grid so the OP doesn't have a constant load like you think. To the OP, I would double check your Modbus meter that should be installed with the CT clamp at the incoming mains supply around the L1 conductor, misconfiguration here will show the results you are getting.

thanks will have a look this morning .. J

 

[12VoltInstalls]

If you have no load then you are generating zero power until you hook up the battery. If you're not putting it into a load then you are not harvesting it at all.

That was what I was driving at

The load isn't important,

it was important because I was trying to understand the 3000W which isn’t possible without a load. So the load is ‘das grid.’

 

[Leeds]

It seems that your hybrid inverter is grid tied and can also charge a battery if it wants to. You've told it to only use solar to power the battery for some reason.

If you change that setting back to letting it manage the battery optimally would it put 1.5k to the grid at the same time it puts 1.5k to the batteries?

It may be as simple as it's trying not to max out the current to your battery bank.

 

[davidellis]

Hello everyone,

I have been using a 6kw array with a Solis single phase inverter since June 22. (Solis RHI-6K-48ES-5G).

There was an issue with the installation whereby the batteries would not charge, 3 * Pure drive (II) 5kwH batteries.

Turns out the inverter was at fault, the inverter was replaced on Monday with a new Solis S5-EH1-P6K-L.

The batteries are configured as "self use" with "grid charging" disabled.

I've noticed that when the batteries are connected, and able to charge from the solar panels, the incoming solar energy drops by around half, i.e. if the incoming panels were registering 3.0kw on the app, when the batteries are connected, this value drops to around 1.5kw (repeatable and fairly linear), has anyone else had this experience, thought it may be the incoming DC feeding directly to the batteries, however I'd have thought the incoming value would have stayed at 3.0kw, and have shown some of that energy going to the batteries.

The energy for the day reports as this much lower value (i.e. 4kw rather than 8kw)

Thanks.

Hi
I'm interested to hear if this has been resolved.

I have a Solis RHI 6K 48ES installed with 2 x 5KWh Puredrive batteries. and 7.6 KW array. This system was installed like this from the start BUT both the installer and I are of the view that it is delivering about 40% of what was estimated. We have measured illumination using a solar irradiance meter (pyranometer) this would confirm an expectation of higher generation.

We had not thought of removing the batteries and seeing if generation improves! Clearly our figure of 40% of estimate is remarkably close to the 50% reduction on adding batteries mentioned in this post.

With the battery configured, the inverter system shows a clear onscreen breakdown of PV generation, local consumption, battery charging and excess PV generation export.

Some of the app reporting is garbage with a battery attached. The only PV summary generation figures for a day that appear correct are the figure against the solar panel icon in the Solis overview diagram and the PV figure in the detailed reporting if you select PV generation and choose a particular day)

For others who have raised questions about energy usage etc. I am also monitoring total import / export and usage profile using Myenergi app and recording the PV generation form the inverter screen on a day by day basis. It is clear to see looking at the detailed Solis time based graphs that there is no 'hidden generation' or charging of the batteries in excess of the 'declared' generation.

I am also running Tigo optimiser monitoring on a minute by minute basis. The panels and optimisers appear to be working as expected. The optimiser reporting is about 12% higher than the inverter reports.

My system is configured as self use with grid charging enabled and excess export to grid allowed so there should be nothing that throttles production. All of these behaviours have been behaving essentially correctly.

The inverter will happily charge the batteries to 100% (Separate issue: but some funnies happen with what the inverter does next - basically it then discharges the batteries to the grid by c 5%! - this is an issue that puredrive are looking at and a site visit is planned). Excess generation above house load and battery charging is being exported ( I once managed to get some Kwh auto diverted by the Zppai charge into the EV)

Our core issue is low PV generation as reported on the inverter generation screen (which thankfully ties in with some of the figures in the app)

My inverter firmware version is 42003F.

I am away for a few days but will try removing the batteries and seeing if generation improves.

Thanks