Array calculation
Power = roof area × panel efficiency. For 5 kW: about 10-12 panels of 450 W ≈ 20-25 m² of roof. Orientation: south, tilt 30-40°.
Inverter selection
By array power with a margin: 5 kWp → inverter 5-6 kW. Hybrid (with batteries) or grid-tie (without).
Battery and UPS
For backup power — batteries with a capacity by the load and hours: 5 kWh covers a refrigerator + lighting for a night. The ATS transfers the load.
Grid connection
Per the local rules: bidirectional meter, permission of the network owner, export limits. The design includes the metering node.
Cable and protection
DC strings — solar cable 4-6 mm², DC breakers and SPD at the inverter; AC side — with RCD Type B if the inverter has DC leakage.
Why design
A solar installation without design: wrong string voltage, overheating, no metering permission. The design is 1-2 hours in GorkyCAD.