The actual reasons for this are both by design and by technical limitation, inverters are only allowed to ramp up and down at specific speeds, turning on a load in the house will draw some energy from the grid in most systems until the inverter has caught up, this could be 5-20 seconds in my expereance, and then, only up to its dc/ac inverters limit. It also needs to be able to shut down quickly if there is a power cut.

Re - the constant trickle, this will be both in and out to the grid all the time as the load fluctuates, the inverter only knows whats happening based on the CT clamp round the incoming live wire from the meter. Unfortunately these CT clamps are cheep and inaccurate devices at low currents. Look at your in home display and watch the live usage, you will see it moving through 100w export and 100w import all the time. 

Swapping out a ct clamp for a double pole meter like an estron connected to the inverter on modbus can get this trickle down to almost 0. This is a little more work so most installers dont bother and use the cheep ct clamp that comes with the inverter. CT clamp £20, meter £60. Cost to customer.. hundreds of pounds over the lifetime of the inverter.

This is an endemic problem of installers focusing on their profit rather than the customers return on investment.

Hi 

I’m new here and trying to find any advice to my solar issue which @downing123 did experience and maybe @davericho may have experienced.

3 phase Solis 6kw hybrid inverter, 6.6kw array and 3xFox HV2600 Batteries

3 Issues:

1. A constant low level ‘leak’ whenever solar is being produced, or no solar and just battery - eg on the app this morning Yield of 2.6kwh, Exported 1.16kwh, zero to battery BUT not significant enough to show on the Graph for ‘Power to Grid’. Consumption at all times today has been greater than yield (air source heat pump). I understand that low levels to the grid do happen but my net to the Grid has been 30% since December. Friday 20th Jan out of 10kwh yield 4.22kwh to the grid and batteries only hit 40%!! The sunnier the more I lose!?
2. Larger and recordable on the ‘Power to Grid’ Graph spikes to the Grid when batteries not even fully charged. Worst one was 1.489kwh to the grid when the battery chipped in 0.203kwh. Battery to grid has also spiked over 1kwh.
3. Batteries stop discharge at 20%

Yes I have an installer who is waiting to hear back from Solis which is taking an age but any comments would be helpful.

Thanks

Given your notes @Tomb2100 you may want to check your inverter settings. These can determine what priority is used in charging/supplying/feeding to grid and it sounds as if these might be not optimal for your system. 
Discharging of a battery system depends on the chemistry - a Li-Ion battery will normally have a 10% minimum level set as it is difficult to charge at very low levels. 
If you can check some of those parameters that might help

Hi /mbu198

Did you ever get a fix for this from Solis? I have the exact same issue with my Solis inverter and puredrive battery setup. It works out that whilst it only costs me 65p per day it’s pretty consistent and spread out over day and nighttime use this adds up over time and is quite annoying.  Thanks Jim

I have a similar annoing issue. I have a new PV 3.2 kwp system, with Solis S5-EH1P inverter, US3000 C battery from Pylontech , SDM-120CT meter coupled with an Eastron split core ESCT-TA16. When the system is not exporting energy to the grid, the meter of my energy provider shows an average input power of 50W, but the inverter and the app show 0w from the grid. It seems like an “error” from the clamp: is it possible or is it a normal behaviour of the inverter?
Thanks in advance for any suggestion!

Hi @fabiodifa , the meter readings from your provider (smart meter?) will be more accurate. The clamp monitor is a general guide but not as accurate. These type of systems also tends to give an update every few minutes so can give false readings every so often. 
There are a couple of things to consider. 
The settings on your inverter which might look at a charge state overnight and

Switching routines which at low input levels from the solar and battery system can cause grid demand as they don’t switch as fast as the demand changes 

First of all, thanks for your reply. It seems like an "offset" related to low power consumption, so I think I can't solve it!

You may be correct @fabiodifa. Your monitoring system and inverter will be taking its feed from the clamp so anything you can do to correct that would help overall. I know that several providers have updated their systems over the last few months so just ensure that you have the latest version (I’m sure you do) and the position of the clamp might be significant as well

I have similar situation with my Sunsynk system the grid seems to supply up to about 20% of my power use rather than draw from full batteries, whatever the load requirement is, But not all the time! Usually runs at about .05 Wfrom grid. 
I also notice that the energy supplied by solar panels , battery or grid seems to add up to about 20% more than the power required! Is this normal? 

Hi @Coypu , most systems do have a need to still draw from the grid. Sometimes it depends on how the system has been set up. There will also be times when the solar production will drop due to clouds or suchlike and it can take a while for the battery to switch in. 
Inverters have their own system monitoring to detect and measure power flow but they are not as accurate and so can give differences in value. 
You might be able to adjust a few things if you thought it useful .. but it needs care when changing settings

Dear colleagues,

our SOLIS hybrid inverter draws a small amount of energy (30W) from the grid when it is charging the battery (at say 1.5 kW) and the house consumes say 500W. This small amount of grid energy is registered by our utility meter, so we have to pay for it, even though there is 1500W going into the battery at the same time We would be happier, it would charge 30W less and draw zero from grid.

As long as we had no battery, we could set “maximum exported energy” (600W) and did consume no energy from the grid. Now we still draw a small amount, even though there is enough coming from the panels.

Any ideas?

It’s all about the inverter settings @marsalek. There’s two considerations:

1. The switch between enough solar to charge and supply the house is often slower than you might think and because it’s all designed to give you what power you need when you need it, there can be instances when you draw from the grid as well (even with a charged battery).
2. The inverter monitors what is being drawn by the house (either via a CT or an internal monitor). This can be slightly off calculation and so not be measuring accurately. 

If via CT, there can be a programmed offset put into the calculations to better match need. 
If just switching time is slow, there’s not a lot you can do. 

You are right, the speed of regulation makes it impossible to accurately track sub-second load and PV-supply variations. I’d try to tweak the settings so that we supply a negligible amount into the grid. Where do I find the offset-settings for the CT meter? I am using Eastron SDM630mct. Thank you!

The offset is normally applied via the inverter settings. I don’t have a Solis so not sure if/where they sit. 
Mine (a LuxPower) has a field on the maintenance page 

I found this article on the Solis support site ..

Although yours is a different type, the page might be of use

Hey @marsalek 

Welcome to the Forum!

I hope BPLightlog’s replies have been helpful to you, do let us know how you get on as it can always be helpful to others in the community to here more experience.

At the moment my solar battery is covering all our power usage overnight (according to the solar app).  Why is OVO showing power coming from the grid?  Admittedly not a lot, but thought it would be zero until the battery discharged.

Thank you.

I guess that it depends on your particular setup.

Is you battery charging perhaps set to trickle charge from the grid when there is no sunlight - ie. overnight?

Most charging systems will not let a battery go flat but will start charging once it drops below a certain percentage charge, which may be as high as 90% or even 100% stored charge.
Depending on your system you may be able to change/lower the percentage at which that happens.
(Think of your smartphone battery, even if already at 90% it will still charge to 100% when connected to a supply).

Do you perhaps have some things that may be designated to always use the grid, so that they are not reliant on the state of the battery? (Wired in fire/smoke/burgular alarms for example).

Hi @Sue732H , your notes from solar and battery use are very common as (you might expect) most people do expect their system to cover everything up to their capacity. 
What is less well known is that the solar inverter - the heart of the system - can often take a few seconds to begin to deliver power from the battery even if there’s plenty stored. That means that a kettle or similar suddenly being switched on (I know there’s no other way) can draw from the grid until the inverter recognises the demand and switches to battery power. 
Some systems are better than others but for the majority, there can easily be times when the immediate need from the property has to be supplemented from grid power until things adjust and your system supplies instead. 
Hope that helps. 

Hey @Sue732H 

Welcome to the Forum

I’m glad to see a couple of our volunteers have already stopped by with some really helpful advice already, I hope you’ve found what they’ve both said useful.

We’ve also got similar topics which may also be helpful for you:

Let us know how you get on, and feel free to ask any other questions you may have, we’ll do what we can to help.

I recently insatalled Solis on grid inverter 10kw. The issue im facing is that even though my inverter is turned on it still drawing energy completely from the grid. My app tells me my system is generating and there is no change in our electric bill. 

It’s best to keep any questions in one place 

On the face of it, it looks like a configuration issue. It may be set and exporting rather than supplying the property. 
What are you seeing on the app?

Here is the message that it's showing me on the app

According to Solis, that suggests a problem either between the inverter and the data logger (that is off line) or possibly an issue with connection via WiFi or similar 

@abdullahahmed @BPLightlog 

Hey both,

I have merged the two threads into one to make this conversation easier! Any questions please let me know