On-grid domestic battery storage

Starfrog

it always seems to cap at 3.6

EVandPV

Starfrog said:

it always seems to cap at 3.6

Looking at our stats from previous years, looks like our system starts to reach max power from around the second week in March.
If your not seeing higher generation by then, there's something not right.
Having said that, I'd have expected to see slightly higher figures from a 5.4kw system by now, unless the microinverters have reached peak output, which I doubt.
Do you have a manual for the microinverters ? Should give you the spec.

Starfrog

I have the IQ7+ microinverters so the second column, not sure what im looking for to be honest 

EVandPV

So it says max continuous output of 1.21A(amps) at 240V so multiplied gives 290.4 watts per panel. Therefore 12 panels gives you 3.48kw which seems to match your stats.
Could be that your installer fitted these to keep within the max generation allowed by the DNO ??

Starfrog

the panels say they can generate 455 w per panel so did I waste money buying that and not just 300w ?

EVandPV

Starfrog said:

the panels say they can generate 455 w per panel so did I waste money buying that and not just 300w ?

300w would certainly have been a better match for those microinverters, I would have thought.
12 panels at 455w is overkill if the DNO has limited your install to 4kw which I think is the usual limit ??

Starfrog

I guess it means that each year when I get degraded performance due to age I'll always be on peak performance from my solar panels, surprised that the micro inverters dont do more as they are specifically designed for panels from 230w up to and beyond 440w ? plus this is all a restriction on what I could potentially export which is not my priority but charging battery and powering house is 

EVandPV

Starfrog said:

I guess it means that each year when I get degraded performance due to age I'll always be on peak performance from my solar panels, surprised that the micro inverters dont do more as they are specifically designed for panels from 230w up to and beyond 440w ? plus this is all a restriction on what I could potentially export which is not my priority but charging battery and powering house is 

One other thing I was forgetting to take into account is loss during the conversion from dc to ac.
And you never see the max rated power from solar panels in any case.
So even if your 455 watt panels could output 400 watts dc each, then take off say 10% once that's coverted to ac, your looking at about 360 watts per panel so your really not losing as much as you might think.
Based on that, even with an inverter with higher output, you probably couldn't get much more than around 4.3kw max power from them.
And as you say, the panels will also degrade over time too.
Might be worth starting another thread to see what sort of performance someone else with a similar system is getting.

Starfrog

good idea ill do that later today thanks for your input

EVandPV

Just noticed Chamelion has a 5.4kw system. He posted earlier on the Lux thread.