This morning is bright, and I’m seeing a big increase. Nearly 4 kW at 8:55! At 8:15 I was pulling 2.9kW. That’s a kW up from Monday which was the most recent day that we had an unarguably clear morning.
What I really need though is a gloomy day. The system was always performing well on clear days, but I got the extra panels for better performance on gloomy days.
The Goodwe is behaving differently now (nobody changed any settings on it). Both strings came on this morning and as y’all saw, I got quite excited with the production in the morning. This system was rated at 4kW when installed because it had 12*325W panels. But of course with the strings facing in different directions it was unlikely to ever get into the 4kW ball park. But this morning it did.
Anyway, now the battery is charged, the house is ticking over, and the inverter is only drawing from string 2 - the East facing string. Presumably because it can get all the power it needs from just that one string (string 2 has a higher voltage, so maybe that’s why it goes for 2 ahead of 1). I do the time honored test of turning on the kettle and it wakes up and starts drawing on string 1 again.
At 12:00 the heat pump comes on. I rush into the kitchen and turn on the kettle again. There’s 4kW load, and it draws from both strings and matches the demand.
I am going to need to invent loads in the afternoon now to see exactly what I’ve got and how far I can push it. Good job it’s a long weekend.
See 3 min into the video as he looks for ways to find more load…
Well I was going to start off with running the dishwasher about 14:00. I have previously admonished folks for this heinous deed, but this will be in the interests of science.
13:45, it is still drawing only from the E string. Demand is low 940 to 950W, and it can still get that from the E facing string.
That doesn’t sound right…
It’s very right. The East (the dominant MPPT) is supplying all the power. West isn’t needed - yet.
For the same price why not… But yes we are getting much better production in overcast conditions with the Bifacials than the mono panels
Watching the system work in its current configuration it seems that it prioritises the string with the higher voltage. It goes for that string first, and if it can’t get the power it needs then it goes for the other string. As the afternoon proceeds it draws more & more from the N string.
If I turn on the guest geyser then it maxes out the E string (10 panels, higher voltage), but that’s not enough and so it taps the N string as well.
In the morning, as I posted in another thread, it is pulling all it can get from both strings to get the battery charged.
This poses interesting questions about balancing the two strings and the way that will affect the way the inverter works.