PV system running well for a couple of days now..questions?

[HomerJay]

Hi all, our PV system has finally got up and running properly after what seems to be a very long time. It was constant being tripped by anything that was turned on at home and only when the RCDs were uprated did the system settle down and start working properly.
It’s early days yet but I’ve noticed that it still drawing from the grid when the battery is full-ish and the PV array is generating a few hundred watts. The load in the house can easily be met with the PV + battery but it’s usually drawing 10-20W (0.010 to 0.02W) from the grid! Why is that, and is it normal?

 

[johnb2713]

In my experience, yes this is normal. The inverter works by increasing it's output voltage to reduce the input from the grid. It attempts to get to zero but being digital one step -ve may result in grid import, one step the other way may result in small grid export, it cant get to exactly zero. It also has to know the grid is still there and synchronise to it. For one or all of these reasons it's fine.

 

[HomerJay]

Thx, that makes sense!
I am constantly amazed at this technology. Even on a fully cloudy day, the PV still powered 30% of the load! Awesome!

 

[johnb2713]

Thx, that makes sense!
I am constantly amazed at this technology. Even on a fully cloudy day, the PV still powered 30% of the load! Awesome!

I agree, a couple of days ago we had freezing fog, -4deg C and my panels still produce over 500w which just managed to supply the house all day without draining the battery. In the summer on best days it's staggering, it charges the battery back to full, recharges my EV, Fills the hot water tank and still has some left to export despite running 2 air conditioners as well.

 

[Andy1733]

As John said. Perfectly normal from my short experience with solar.

 

[binky]

My own array still generating 270w despite the heavy frost. My system is nearly 10 years old now, and the panels are rubbish compared to what's available these days.