Given the basic requirements, while planning any type of Solar PV System, the off-grid system differs in design in regard to certain additional components.
Dry and ventilated storage place for batteries, if possible protect against low temp (optimal around 20°C)
Thermal systems
Additional roof statics approx 50kg for 1 installed collector (40kg collector, 10kg mounting system). For 2 collectors 100kg, for 3 collectors 150kg etc.
Plan an additional area, approx 1x1m for solar heater in boiler room and its integration with the conventional heating system.
Optimally angle for thermal systems is 40-45° and results from a focus on energy yields in autumn-spring period. In summer almost every thermal system produces unused excess of energy and in this period optimal system-inclination is secondary. An exception is industrial thermal systems or pool connected, where an excess of energy does not occur, in this cases system-inclination is 30°