EPBT is 4 months in excellent conditions. A south facing facade in northern scotland is about a quarter of this and can gather about 0.4kWh/day/m^2 epbt is sti

EPBT is 4 months in excellent conditions. A south facing facade in northern scotland is about a quarter of this and can gather about 0.4kWh/day/m^2 epbt is still well under 3 years. A 2-3 bedroom apartment has about 7-14m^2 of non-window 4kWh/day isn't going to cover everything but it's decidedly not nothing.