hiddenhippo
Member
I finally got approval from UK Power Networks to install a RHI-5K-48ES and 15kw batteries. The installation went smoothly, as I used a local certified electrician. For back reference, I already had solar installed, using a grid-tied inverter but no batteries, however, the system worked brilliantly and I calculated that ~70% of generation went back to the grid. So I kept the wiring from the old installation and installed the hybrid + batteries.
To date I've been very impressed, we're nearly nett zero from the grid, which brings me to my point. Using the LIVE display on the inverter (and graphs on solis-cloud + app), I always have a trickle of import from the grid, anywhere from 1w through to 100w, with an average of around 40w. This trickle is in spite of the following a) solar generating more than the house demand, b) solar + battery generating more than the house demand. This might be completely normal, but I thought I'd check, and having Googled I can't find anything that indicates whether this is normal or not.
I know that a picture speaks a thousand words, so attached is an image of my installation; ignore the Growatt, this is disabled and no longer used. In summary, we've got the Solis on the right hand side with it's AC going to the Solar AC Isolator, to the solar meter and then to the solar consumer unit. To the right of the solar consumer unit is an Acrel with a CT clamp on the output of the grid meter. The solar consumer unit and the grid meter then connect to some henley blocks before going through the wall into the house consumer unit. The only "odd" thing (for no knowledgeable reason) is that the LIVE and NEUTRAL feed for the Acrel meter come from the solar consumer unit rather than the from the house consumer unit - this might not be an issue though.
Ultimately, is it normal for there to be a constant feed in from the grid even though solar and/or batteries can supply the demand of the house? Equally, the demand from the house can be low/high, it matters not, there will always be some level of trickle import. I've included a picture of the solis-cloud web application and drawn some black lines to show the flow of current. The house demands 223w, the solar panels are generating 535w, yet there is a 28w draw from the grid. I just find this slightly confusing. The solis is configured as self-use with no timers for export/import. Charge from grid is disabled etc.
Any help would be greatly appreciated.
To date I've been very impressed, we're nearly nett zero from the grid, which brings me to my point. Using the LIVE display on the inverter (and graphs on solis-cloud + app), I always have a trickle of import from the grid, anywhere from 1w through to 100w, with an average of around 40w. This trickle is in spite of the following a) solar generating more than the house demand, b) solar + battery generating more than the house demand. This might be completely normal, but I thought I'd check, and having Googled I can't find anything that indicates whether this is normal or not.
I know that a picture speaks a thousand words, so attached is an image of my installation; ignore the Growatt, this is disabled and no longer used. In summary, we've got the Solis on the right hand side with it's AC going to the Solar AC Isolator, to the solar meter and then to the solar consumer unit. To the right of the solar consumer unit is an Acrel with a CT clamp on the output of the grid meter. The solar consumer unit and the grid meter then connect to some henley blocks before going through the wall into the house consumer unit. The only "odd" thing (for no knowledgeable reason) is that the LIVE and NEUTRAL feed for the Acrel meter come from the solar consumer unit rather than the from the house consumer unit - this might not be an issue though.
Ultimately, is it normal for there to be a constant feed in from the grid even though solar and/or batteries can supply the demand of the house? Equally, the demand from the house can be low/high, it matters not, there will always be some level of trickle import. I've included a picture of the solis-cloud web application and drawn some black lines to show the flow of current. The house demands 223w, the solar panels are generating 535w, yet there is a 28w draw from the grid. I just find this slightly confusing. The solis is configured as self-use with no timers for export/import. Charge from grid is disabled etc.
Any help would be greatly appreciated.