'Decent' panels come in a range of outputs. Not AFAIK, but IDK.
That means nothing in terms of whether or not it's possible to have a 'decent' installation with 21 panels outputting less than 4kWp.
If you're posting on a subject that comes under AFAIK, then I suggest you don't bother.
So which ones are 190W?
Efficiency is when I replaced the roof and windows in my flat and the tenants could keep the place warm by turning off the heating and breathing.
JGH
Isn't turning off the breathing a step too far... ?
It's lifestyle management to reduce condensation.
Owain
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