Hello,

I have an installation with 2 deye 3p hybrid inverters. But i have  a purchasing power come to grid constantly day and night. I don't understand where the problem comes from. This continuous power is about 10 to 15% of the power of the load (see attached graph). Can anyone help me to solve this problem. 

Please share your work mode 2 screen

here is the view

How much is your SOC at 6:00am? It looks like you are stuck at 25% from 6 to 9 therefore you are using grid to supplement your load.  

Edited January 19, 20233 yr by JacoG

betwenn 6:25am to 8:35 the SOC is at 25%. 

the energy demand increases from 6:50 a.m. until 9:05 a.m.

we see that the grid demand remains at between 10 and 15% even when the battery is full and that I sell to the grid.

I do not understand why I have a consumption that comes from the grid permanently (see this graph). 

Do a test and set your 6:00 to 9:00 timeslot to 25% and check if this helps with the purchasing you do in the mornings, also there will be continuous draw of 20w throughout the day as per your settings, this is for the pre-paid meters not to trip.

At about 3:00PM and 4:00 PM there was a small time where PV production was less than consumption power.

 

Edited January 20, 20233 yr by JacoG

12 hours ago, Pierre-loiret said:

betwenn 6:25am to 8:35 the SOC is at 25%. 

 

On 2023/01/18 at 7:38 PM, Pierre-loiret said:

Your un-ticked 06:00 to 09:00 time slot at 25% implies to not drain the battery lower than 25%, so use grid if extra power is required...

Looking at your graphs etc. I think your battery is too small... but your sell at 1kW max is also not very much, if you want to try and sell 1kWh when the sun is shining, you'd have to slow down the battery charge rate, so it charges over many hours so it will only be full by around, lets say 1600, when the solar production is going down anyway, that way you can probably/hopefully cover your own consumption + be able to export a few hours at a rate of 1kW...

Thanks guys for your explanations.

The installation is composed to 20 kWp and 40kWh of lithium battery.

the objective is to consume as a priority, to recharge the batteries for the night and then to sell the surplus

for example, at 2:15 p.m. the production is greater than the load but I still have 10% of the energy coming from the grid (see graphic).

If i put the value "zero-export power"  = "0", what's going to happen ?

 

 

 

 

On 2023/01/17 at 11:17 PM, Pierre-loiret said:

Hello,

I have an installation with 2 deye 3p hybrid inverters. But i have  a purchasing power come to grid constantly day and night. I don't understand where the problem comes from. This continuous power is about 10 to 15% of the power of the load (see attached graph). Can anyone help me to solve this problem. 

The battery is fully charged by 16:00, then you have some big loads culminating with over 6mw at 21:00. There's no PV, so your system is going to resort to battery. Which results in your SOC being low come 6:00 when the loads increase again. 

I'm guessing your system is set up to not discharge past 25% remaining SOC, so at this point it is going to resort to grid and then the PV which is coming on line. 

If you're in South Africa, or any other territory where outages are common then you're vulnerable at that point. Low SOC and if the load shedding starts at 6:00 or 8:00 then the system is going to deplete the battery even more. 

We all face this problem. We all have to learn to change our usage by moving as much consumption as we can to the sunny hours. That's how you maximise the benefit of a PV system. Can you run that load during the day? 

What battery do you have? Maybe a bigger battery will give you more residual SOC at 6am, and thus less need to resort to grid. 

Ok. Just noticed you have lots of battery. Also a non-trivial steady load through the night. 

Something has to give, or you can accept that you're taking a big chunk out of your bill. Though if you have time of use billing, then maybe you don't want that purchasing from 6 to 8.

Which brings us back to something having to give. More battery (expensive), or move loads into the sunny hours and export less. 

40kwh of battery is an impressive amount. Care to share some details of your system? 

On 2023/01/20 at 10:14 PM, Pierre-loiret said:

the objective is to consume as a priority, to recharge the batteries for the night and then to sell the surplus

Your surplus is limited to 1000W/1kWh, though, so why is that? on purpose or don't you realise that you could conceivably sell more? Either way, your graph shows that the SOC is 100% or close to it by 10:30 or 11:00, if this was my setup, I'd slow this down (also for the longer life of the batteries, its better to charge slower than to try and dump as much as you can into the battery in as short a possible period) and, if possible/allowed, export more power, say 4kW/4000W (it will only hit that number if that amount of energy is available/not used for own consumption/battery charging)... your consumption at 2500W or so for the night when everyone's asleep, seems a tad high, but presumably you're running heaters etc. not a good use of batteries for that sort of load...

the system is located in ivory coast. It supplies a villa. The objective is to make the house autonomous.
The installation is composed of 19.5 kWp, 10 kWp oriented East and 9.5 kWp oriented West. We can see on the graph that the maximum instantaneous power does not exceed 12 kWp. It is also equipped with 8 Lithium LFP 5000, 51V or 40 kWh batteries. In reality, I have 12 batteries, but the manufacturer recommends not putting more than 8 in parallel, in order to avoid communication problems with the inverters (BMS address) and therefore charge and discharge management.
All the equipment in the house is powered via the Backup output of the inverters, except the swimming pool pump which is powered via the public grid. It is for this reason that I send 2 kW back to the public grid (1 kW by inverter) – it is 2 kW used to supply the swimming pool when I have surplus production.
I limited the charge and discharge to 120A or 6.1kW per inverter.
My question is always the same, how can I reset the consumption that comes from the network during the day and when the battery is full?

Here is the chart of the day.

 

 

27 minutes ago, Pierre-loiret said:

My question is always the same, how can I reset the consumption that comes from the network during the day and when the battery is full?

I'm assuming these are 3 phase inverters? either way, are the current transformers installed so it can accurately determine what comes in and goes out to the grid? I'm guessing no, since nowhere can I see power being fed to the grid except between probably 14:30 and 15:30 on the last graph, but you should have lots more power available for this, much earlier in the day already. Also if the CT's are correctly installed you should be able to feed power to the grid side of the inverter to cover all loads, pool pumps and all, if enough energy is available, of course... if this is correctly installed you would select zero export to CT, I think, but I actually don't have a  Deye, but a Sunsynk which looks slightly different from a user interface/menu perspective...

I don't select zero export CT because i don't use the load grid output. I did not connect the pool pump to this output because there is a distance (cable length) of 120m between the inverters and the pump.

as the pump is supplied by the grid upstream of the inverters, I preferred to take the option of injection into the grid (see schmatic in attached).

15 hours ago, Pierre-loiret said:

as the pump is supplied by the grid upstream of the inverters, I preferred to take the option of injection into the grid (see schmatic in attached).

ok, well, back to the graph, this is a combination of both inverters, is the grid power used shared by both or is only one inverter taking from the grid, is there a way to check this? are both inverters identical in setup/settings, other than that one is obviously the master and the other one the slave? How are the solar panels distributed, both inverters identical in terms of panels and directions of the panels?

 

On 2023/01/18 at 7:38 PM, Pierre-loiret said:

 

the settings as they are, I would interpret them as:

from 01:00 to 06:00 use the grid to charge the battery if the SOC is less than 30%
from 06:00 to 09:00 use the grid to help solar power to supply the loads if the batterys SOC is 25% or less
from 09:00 to 13:00 use the grid to help solar power supply the loads if the batterys SOC is less than 90%
from 13:00 to 16:00, same as from 09:00 to 13:00
from 16:00 to 18:00 use the grid to charge the battery if the SOC less than 50%
and finally
from 18:00 to 01:00 us the grid to power the loads if the batterys SOC is 25% or less...

That the inverter(s) may use the grid at times additionally to other power sources can usually be attributed to change in load that the MPPT is not able to adjust for immediately, usually the battery should pick up the slack, but maybe there are other settings that may influence the behaviour,

On 2023/01/19 at 10:12 PM, Pierre-loiret said:

we see that the grid demand remains at between 10 and 15% even when the battery is full and that I sell to the grid.

That is actually referenced to the W scale and not the % scale, the % scale only refers to SOC everything else refers to the W scale on the left hand side... so its not that bad, but ideally you would like the draw from the grid to disappear mostly and more being sent to the grid, but what I'm missing or not understanding is the Production Power graph, which seems to indicate a lot of shading/clouds... is this the case?

yes, the both inverter are identical (12 kW - 3P)

inverter 1 is supplied with 9.9 kWp and inverter 2 with 9.45 kWp.

the variation in production is linked to the passage of clouds. 

 

14 hours ago, Pierre-loiret said:

the variation in production is linked to the passage of clouds. 

ok, well, then excess power to be sent to grid will only be available when clouds are not blocking sunshine...

your 20W/inverter Zero-export Power would imply that at least 40W will be consumed by the inverters from the grid all the time... you could try and set this to 0 on both of them and see whether that improves the grid consumption, but all in all, I don't think you are using excessive amounts from the grid...
on your 1st post/graph the grid consumption between 07:00 and 09:00 is related to not enough solar yet and battery SOC limit that is set, reached, the grid power consumed during the rest of the day, seem to not exceed 200W, maybe 300W, when solar production was down and local consumption was high-ish... so that's all the way it should be, what you are not showing on the graph is the power supplied by the battery or supplied to the battery, only the SOC...

your next graph Posted Friday at 10:14 shows 6kW local consumption between 14:30 and 16:30, with around 200 to 300W coming from the grid, again, I would call this normal, if you disconnected the grid at this point, the battery would have taken up the slack...

your next graph Posted Sunday at 08:10 shows some export to the grid between 14:00 and 15:30, I'd say, not much coming from the grid mostly, except just after your marker, probably 400 to 500W peak when consumption peaked around 9kW, I wold not call this abnormal, there are probably settings won the Deye which will try and reduce the grid usage some more, but I don't have a Deye myself and don't know all the settings well enough to suggest what you can do, but looking at the amount of power used from the grid, looking at your graphs, I would not be worrying too much, I would wage war on the clouds instead 🙂, with the amount of PV installed, I would want more power produced and thus exported to the grid installed 🙂

One thing that doesn't make much sense to me though on the last graph, is it shows some purchasing power from 14:00 onwards and at the same time showing feed-in power, how does that work? I'm guessing your graphs are via Solarman PV, ideally you probably want more accurate data, locally, maybe that also doesn't only have 5 minute granularity, but more like 20 or even 10 seconds granularity, then you could at least get a much more realisic idea of what is going on, the 5 minutes granularity does not show potential power consumption spikes that cause the inverters to take some power from the grid, possibly...

Either way, again, looking at the amount of power you really are consuming from the grid, I would not be too worried, if I were in your shoes...

Thank you very much for your clear and educational explanations. I will try to refine the settings to optimize consumption.

 

I have a technical question for which I cannot find a satisfactory answer. maybe you can help me.

I have 12 batteries to 5kWh , but I only use 8 because the battery manufacturer tells me that I cannot put more than 8 in series or parallel. Also, Deye recommends having a single battery group in the event that there are several inverters in parallel. but I want to use my 12 batteries. Do you think I can connect the batteries as shown in the attached diagram? or is there a risk for batteries or inverters?

 

This Deye Video gives an excellent explanation of System Work Mode:
 

Please read Deye Manual pg 30-31/section 5.7/5.8 which further explains System Work Mode
https://www.deyeinverter.com/deyeinverter/2021/02/06/502012021【b】储能单相说明书sun-3.6-5k-sg03lp1-eu-ver2.0-deye.pdf

On my SunSynk, I have Grid Charge ticked for all periods and all SoC/Batt of 20%
If SoC > 20%, then use battery for load (don't use grid)
If SoC = 20%, then switch to grid for load, stop using battery
If SoC < 20% use grid to charge battery and for load - only happens after grid fail and restoration (load shedding)
During the day, Solar will go to load, then battery, then export.
I've set my Shutdown/Low Batt/Restart to 5%, 7%, 10% to work with the 20% SoC in work mode.
 

 

Edited January 24, 20233 yr by system32

13 hours ago, Pierre-loiret said:

I have a technical question for which I cannot find a satisfactory answer. maybe you can help me.

OK, what batteries are these? It could well be that the BMS on these is setting a limit of 8 batteries and this would be a software with possible hardware limitation, obviously in these parallel configurations there would be one master BMS that keeps tabs on the others connected in the parallel battery. The limit would certainly come from the battery side and not the inverter, possibly there may be a BMS firmware update available...

Running each inverter with its own 6 paralleled battery is also not a great idea, since the master inverter would probably assume its battery is also its paralleled inverters battery which would not be the case, assuming both batteries start off fully charged, then they should both discharge fairly evenly, since the load should be carried by both inverters fairly evenly, but that's not guaranteed 100% and what if one of the two inverters goes faulty? now only half the battery capacity would be available...

I am assuming the batteries are communicating to the master inverter (how else would the SOC be figured out), what interfaces is used CANbus or RS485 and what make and model batteries are these? Lets see whether the manufacturer has a BMS firmware update available to allow an array of more than 8 parallel units... the only other option would be to run the batteries in user/voltage mode, no comms between the various batteries and no comms between the batteries and the inverter(s) and run them solely in Voltage mode, but then you would not be able to determine SOC with any real certainty and it would be a bit more messy, but since your grid seems to be a hell of lot more stable than here, maybe it would not be too bad, this way, at least you could parallel up all 12 batteries, but without comms...

Edited January 25, 20233 yr by Kalahari Meerkat
speeling

Thanks you very mutch for your explination.

I use the "CAN"

For the batteries  : As the two inverters are in parallel and the consumption is balanced between the two, I thought that I could only connect the BMS of 8 and leave the other 4 without connecting the BMS.

Can there be a risk of deterioration?

The batterie Brand is SUNKET-ESS 5000 LFP.  Link for the manual : http://26435890.s21i.faiusr.com/61/ABUIABA9GAAgjfLxiAYooNq__AQ.pdf

22 hours ago, system32 said:

This Deye Video gives an excellent explanation of System Work Mode:
 

Please read Deye Manual pg 30-31/section 5.7/5.8 which further explains System Work Mode
https://www.deyeinverter.com/deyeinverter/2021/02/06/502012021【b】储能单相说明书sun-3.6-5k-sg03lp1-eu-ver2.0-deye.pdf

On my SunSynk, I have Grid Charge ticked for all periods and all SoC/Batt of 20%
If SoC > 20%, then use battery for load (don't use grid)
If SoC = 20%, then switch to grid for load, stop using battery
If SoC < 20% use grid to charge battery and for load - only happens after grid fail and restoration (load shedding)
During the day, Solar will go to load, then battery, then export.
I've set my Shutdown/Low Batt/Restart to 5%, 7%, 10% to work with the 20% SoC in work mode.
 

 

thank you for your clear explanations. when the battery <20% you recharge it with the network up to what level? to get the most out of solar power, I want to limit grid charging at night.
Also, do you know if I can make changes to the remote settings with SOLARMAN PRO.

do you know what the role of "zeroexport power". this box defaults to 020 

16 hours ago, Pierre-loiret said:

thank you for your clear explanations. when the battery <20% you recharge it with the network up to what level? to get the most out of solar power, I want to limit grid charging at night.
Also, do you know if I can make changes to the remote settings with SOLARMAN PRO.

do you know what the role of "zeroexport power". this box defaults to 020 

>when the battery <20% it with the network up to what level?
Grid is used to charge from 7% to 20%.
Grid charge stops at 20%.
When sun comes back sun charges from 20% to 100%.
Grid is never used to charge above 20%.
Above 20% load will use sun & battery.
At  20% system switches to grid for load.
Will only go below 20% if there is a grid outage, when outage over, grid is used for load and to change to 20%

>this box defaults to 020 
This is a "trickle feed in" to prevent some older non-bidirectional meters from tripping.
Often used in South Africa where most system are for self consumption and no grid feed out.
Not applicable if you grid feed out / sell to the grid.

>do you know if I can make changes to the remote settings with SOLARMAN PRO.
Apparently you can, but you need to request Deye to enable this by email to [email protected] 
see https://powerforum.co.za/topic/15995-sunsynk-change-settings-remotely/?do=findComment&comment=146200

I use Solar-Assistant.io (connected to RS485/modbus) to change my settings remotely.

Edited January 26, 20233 yr by system32