Solar and Grid readings - / +

Sometimes i see my Sense Monitor goes negative for solar usually before a significant change in solar power maybe from a cloud cover passing over my system :thinking:

What do you think?

Are you sure your system is setup right?
Imo seems like a wong config: supply side vs load side setting.

Yes, it is. Sense finalised the setup after submitting schematic and pics.

This is what it now shows

I have a 8kW hybrid inverter with 20kW of battery storage

Got it.
In short: there is no good way for Sense to measure your setup.

Longer version:
You probably have a what is known as a secure load (panel) where all things are connected that you want to stay on when there is a power outage.
So whatever is hooked up to that, draws power.
When there is no sun it comes from the grid and shows as a negative on sense (your -299 watt from the first picture) because they instructed you to hook it up through the PV CT from the Sense unit.
In the second picture it shows your solar is generating 4477. but what you don’t see is that 299 watt load (assuming it is kind of stable, which is probably not the case) that is also compensated by your solar. Your PV is generating 4776 watts.
So IRL your PV system produces more, but before Sense can measure it, it was consumed by your backup/essential loads. Only the surplus solar is measured and injected in your main breaker panel. In your second picture you have an additional 357 watt consuming energy.
Since you have batteries, why isn’t that load compensated with energy from your batteries.
My hybrid inverter comes with CT’s and when I set it up right, would use battery power for “own use” so basically go through the night without pulling any energy from the grid. Does your inverter setup have CT’s ?

Hope my explanation helps.

Out of curiosity: what brand/model inverter/batteries do you have?
I am installing a hybrid inverter with batteries myself atm in addition to my normal solar.

@dannyterhaar , thanks for your explanation.

I have two panels, main panel with a few 220v circuits that are off and not used at the moment. And the distribution panel that is powered solely from solar and battery backup for the house.

My Deye (Sol-Ark) inverter with 2 - 10kW lithium battery packs and the inverter does come with CTs.

My batteries were providing power to the house when i took that screen shot from sense but it wasn’t showing that. I could see it in the inverter app Solarman Smart.

This is my main panel with Sense CTs and Deye CTs on the utility main.

This is showing the Sense solar CTs on my inverter and battery lines to the distribution panel.

This is a pic of my setup.

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Nice & clean setup!

I just finished installing my 4 x 5.76kWh (5kWh usable) batteries yesterday:

Each weighs 78kg/155 Lbs.
My “blue sun” inverter seems identical to what you have:

Probably another Deye rebrand.
Yours also has 4 mptt inputs up to 12kW and 8000 watt AC (grid tie or off-grid) ?


Yes, our inverters look identical :grin: with same capabilities.

Your setup will look awesome once completed!

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Back to your original question.
Can you post a screenshot of 24 hour energy meter ? either in app or on desktop (more resolution :wink: )
It seems that is an issue with your inverter setup.
It would mean that either your batteries are empty and it starts to use energy from the grid at that point or the setting to supplement “own usage” is set in a wrong time frame or something.

Energy won’t show it going negative (unfortunately).
Could you also post a day worth of solar production with the cursor on the time when it was using electricity from the grid?

My setup eats about 15 watts at night. It does show negative (-0.0) but not enough to give a reading in kWh. I assume 0.015kWh is rounded off to 0.0

In your case however it should show up.
Going over your hour by hour numbers, you should be able to see when it starts.
Look if you have a mode/timer set for that time or maybe just because your batteries are down at that point where it stops to drain and starts supplying that from the grid.

Based on the Solarman Smart app for the inverter my batteries were full

From Sense it doesn’t show what we saw in my first screenshot

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You now showed where there was actual sun, can you show mouse-over for 6 or 7am when the system is feeding from batteries?
Do you have split phase (2x120 volt & 240 volt) like in the USA?

In the night my batteries are at work so it is showing my solar and usage the same

Yes, split phase, I have 110v & 220v

So there is a small error in that your inverter does not compensate to zero usage.
You show 100 watt difference at night when running from the battery & 300 just before sunset.
Could you check the following:
Make sure that L1 to the inverter has the right CT for L1 hooked up.
I have seen (different inverter setup) where they hooked the L2 CT to the measurement input of the L1 CT (and vice versa) and that gave a lot of weird effects.
If that seems to be connected correctly, I think you should contact the dealer/manufacturer.
In that case it seems your setup isn’t performing as intended.

@dannyterhaar , thanks for feedback so far!

I will make contact with my installer and have them look into the issue since im currently out of country.

Does the Sense solar CTs have makings to identify which one is for L1 or L2?

You should check both the Sense & the hybrid inverter for correct L1 & L2 hookup with the CT’s
Since Sense seems to work correct, I have to assume if there is a mix-up it should be at the inverter.

@dannyterhaar , Ok. I have sent the installer a message to look into it for me.

I will revert once i have an update.

Thanks again!

How long have you had the system installed. How much kWh was charged by your utility company at the last bill ? should be very close to zero.
Do you know?

I editted a picture I ripped from installation manual from my inverter that shows L1 & L2 and the CT’s for L1 & L2

purple & green lines are the wires attached to the CT’s with the RJ45 plugs on the other end that plug into your inverter.

Hopes this helps for your installer

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