Why is my Solis solar inverter drawing energy from the grid?

Good question this, @Mbu1982 - great to see your green tech in the home: solar and storage!

We do have forum members with solar panels and I’d like to see if anyone has any suggestions to check for this. 

@EverythingNeedsAUserName and @PeterR1947 are often happy to have a look at these solar ones. I hope they don’t mind me tagging them in this one. 

There’s also a similar thread from @dnshorto here:

My trump cards are the new-to-solar @Jequinlan and the smart home guru @ArundaleP. As a group if we can’t advise you of a next step, I don’t know who can!

Here is my current state and a small flow is going TO the grid...

Thanks for the responses @Jequinlan @Tim_OVO @PeterR1947 I tend to agree with Peter, in this day an age the switch between should be instant.  When I am generating enough energy or have a battery over 20% I do not expect to have any energy to be drawn from the grid.  Does this happen with all inverters?

@davericho can you let us know which battery system you’re going for?

@Mbu1982 are you aware of this new 10 second portal view?

Thanks Mbu1982 really would appreciate your Solis update.

Clutching at straws but have tried disconnecting everything to see if you draw power you may have done this, forgive me if I missed you had.

Thanks for confirming, @davericho - I’d love to hear back from you post installation so we know how it went, any unexpected complications or pleasant surprises. Do you need to let the DNO know?

This is also something I’m keen on hearing back on @Mbu1982...

I have a new solar system, so this is my first few months of production. That being said, I did a lot of research before installing my system (I tried anyways, some of it doesn't make sense until you have a system installed), and I have a spreadsheet every month of exports from an emporia energy monitor (CT's on individual circuits and my mains) as well as an export from my inverter, and an export for every 15 minutes from my power company. All the data is within 2-3% accurate of each other for production/consumption.

My Luxpowertek inverter also imports power from the grid every day. The average over the 3 months since it was installed is 0.26 KWh a day.

My neighbour, who has had solar pv with batteries for many years, warned me that the system would import from the grid when there was a sudden demand for power from the house while the batteries got up to speed ie because the batteries are slower to react than the equipment using the power.

Yesterday the system imported 0.2 KW hours in total, mostly when there was a spike in demand which exceeded the solar power being generated at that moment.  The demand was from the electric hob.

The system also imports small amounts from the grid for no reason that I can see, usually when the batteries are charging. Yesterday,  for example, it imported 109 watts when the data showed the system was generating 1796 watts, the batteries were 91% full,  the load was 177 watts and the charge going to the battery was 1691 watts. The load remained steady before and after. The readings for the power generated and the charge to the batteries, when it imported the 109 watts from the grid, were more than the equivalent readings before and after.

Is it something we have to live with, or can the inverter and battery technology solve the problem or does our domestic electrical equipment need rethinking to work in synch with solar PV systems?

So far (fingers crossed) the savings from my system far outweigh the cost of the imports.

Hi @Jequinlan. New Solis system installed on Friday. I wonder if you would know why my system is exporting to the grid when the batteries are not full? 

It is worth noting that most (if not all) inverters do not react instantaneously and so if the sun disappears behind a cloud, there is a balance needed to control power from solar PV into/from batteries and to maintain supply from the grid - this is where there can be a feed back to the grid at time while the system is balancing. 
​​​As @Jequinlan mentions, these flows are normal but overall the system does what is required. 
I’m sure in future systems will be able to respond much faster on switchover. 

Hi, I have a 3kw PV system that’s 8 years old which was using 3x basic inverters so have changed them out for an 8kw solis 5G and 2x Basen green 51.2v 100AH batteries in parallel and I’m at my wits end with it to be honest. The batteries don’t seem to communicate with each other to balance charge or load, once the batteries are getting low SOC the difference becomes too much for the inverter  and it gets muddled which one to read and what to do. I manually charged both batteries to 100% over the weekend and disconnected them from the inverter to let them balance voltages as per my suppliers instructions yet today one is down to 17% and the other 31% so the inverter wants to charge from the grid because of the 17% battery being below the 20% minimum SOC that’s setup but then it reads the SOC of the 2nd battery at 31% so switches from charging the battery to using the battery for a few seconds until it reads the 1st battery so reverts to charging again and round and round this cycle goes. 
 

My current desperate move is to remove the CAN link between the batteries so that the inverter only reads one of them but I’m worried that once the better weather comes round it might over charge the battery that doesn’t have a CAN link. 😭

I have them setup as battery 1 and battery 2, my supplier assured me they were compatible ☹️

Basen is still not listed on the Installation manual