Solis RHI-3.6K-48ES-5G stuck in off-grid mode

[MikeyG]

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Hi All,
Main issue is as per title: inverter is stuck in Off-Grid mode. I used Self Use over the summer, which worked well, priority PV order Load > Battery > Grid. Now the UK has moved into pseudo-monsoon season, I'm only generating 1kWh/day, so I shifted my loads to off-peak grid hours. This includes direct consumption (appliences that heat water). There's a useable 9kWh of PV battery and I set charge and discharge time windows under 'Time of Use'. Contrary to the manual, all 24h must be covered and "Optimal Income" = Run to apply. Charging off-peak worked well, but the Inverter then proceeded to empty the batteries to the grid immidiately it was allowed (pic). To halt the energy dump and run the house over with my purchased kWh, I set the inverter to Off-Grid. But my house loads are hooked up to grid, so I can't disconnect the grid and run the house.

The inverter response is to discharge batteries at <100W only, use the 1kW PV to recharge the next day, and effectively, the house runs using grid power as if no PV is there (pic). I have reverted all settings to Self-Use as per summer: no time windows, no charge from grid allowed, "Optimal Income"=Stop (pic). Full reboot with all power removed for an hour: PV, Battery, grid. Still it behaves as above and reports 'Off Grid' as the mode (pic).

Any suggestions folks? Manual attached including my highlights and text box notes.
Thanks in advance for your time and help.
Mike G

 

[kropaske]

Try set it like this:
Go to storage mode and select Self use to ON, go to Time of use and change Optimal Income to RUN, set charge and discharge current according to your batteries specs, set first charge time to whatever your cheaper tariff hours are, leave everything else unchanged (all to 0), make sure that charging from grid is set to ALLOW. Scroll through all other modes and set them to OFF.
Test

 

[marconi]

Please would you post pictures of your 'Time of Use Self Use' and 'Time of Use for Feed for Priority'. See Appendix 10.

On page 45, 'Self Use' is stated as 'On'. I may be mistaken but I think when something is selected and actually on the legend is light blue.

And when you have selected an option you need to press ‘enter’ to store it.

 

[MikeyG]

@kropaske
Thanks! I am no longer stuck in 'Off Grid' and the energy flow diagram has regained the path from the grid to the house. Hurrah! Pic shows PV system disabled.

What I was doing wrong was falsely assuming that selecting one storage mode would de-select the other storage modes. Your advice to disable the other modes manually did the trick: both battery and PV are back online: that's significant progress. Pictures show back to Self Use behaviour.

The inverter response to being in Self Use but with Off Grid left on was to ignore battery storage. The effect was to run the house off the grid only, which the inverter could stop by feeding power to net out the house, but didn't.

 

[MikeyG]

Please would you post pictures of your 'Time of Use Self Use' and 'Time of Use for Feed for Priority'. See Appendix 10.

On page 45, 'Self Use' is stated as 'On'. I may be mistaken but I think when something is selected and actually on the legend is light blue.

And when you have selected an option you need to press ‘enter’ to store it.

Thanks Marconi. I would prefer that the selected choice was blue but Solis decided otherwise, selection is white and the rest is blue. The behaviour I see is that 'Time of Use' over-rides (higher priority) than 'don't dump my PV battery energy back to the grid'. Backflow power = 0W does not stop this. I still have Self Use = On whilst my PV might generate but to stop the inverter exporting my battery gains I disabled 'Optimal Income' today. This prevented immediate export of stored energy after sunset. I throttled discharge current to confirm the behaviour. Before this, discharge time window applied but discharge power was ignored. I think Solis have their priority order wrong. Do charge from grid and don't export to grid should over-ride the time windows of Charge and Discharge.

 

[marconi]

I am not familiar with the Solis and found the manual light on detail. Before I replied to you last time I found this youtube clip which says that if you have a discharge time window which is non-zero and 'Optimal Income' selected then when the discharge window starts the inverter will discharge the battery at maximum rate of the discharge current setting to earn feed in credit. So it seems the logic for discharge is to sell back electricity stored in the battery when allowed. Your power graphs indicated something starting at 0800 each day which made me wonder about what windows you had open for discharge. The ability to set a time period for discharge is to take advantage of any variation in time of day feed in tariff. Optimal income is for self-use otherwise feed-in; if it cannot do the first it does the second determined by the discharge window. Thus to avoid battery discharge the discharge window must be always closed. Then with Optimal Income set the battery will only support self use and be charged offpeak according to the charge window.

See 1 minute in:

 

[MikeyG]

Thank you for your time Marconi, much appreciated. My strings are East and West as I have no South facing roof. I recommend Q-panels off-axis: brilliant performance! According to PVGIS and results this year this only hurts me in late Nov - Jan, and that matches my output except for the weeks of rain in the UK of late. So I generate early and finish late. It's unfortunate that we have to reverse engineer Solis behaviour by experiment. Their Self Use profile worked well during summer when I would fully charge the batteries. The published feed-in profile Load > Battery > Grid applied. I assumed, wrongly with bad results, that I required discharge after the house came online. As the video stated, Solis empties the batteries as fast as it is allowed. When I didn't have exactly 24 hours set, no settings were applied. I will try this again as it is an alternative to 'no Backflow'. I can confirm that Discharge time window supersedes Backflow Power settings. I had these set to OFF and 0000W, and it did not stop the inverter trying to empty the batteries. The 'Optimal Income' time settings appear to be the master. The 'Optimal Income' current limits apply, which makes it possible to try experimental settings with throttled current so they are lower cost. Progress, I will test and report.

 

[RichardM]

It's excellent that you responded to a reply that helped solve your problem. This, as well as acknowledging the member that helped also helps everyone else who may face a similar problem. Well done to both of you.