For a flat roof terrace the Solar Panels will require about shadow free 100 square feet area per Kilowatt of Solar System. For a slant roof Solar Panels will require about shadow free 80 square feet area per Kilowatt of Solar System.
Solar Modules Generate DC Power. The Solar Inverter converts it into AC Power. The AC Power Generated is Synchronized with the Grid Power by matching its phase, frequency, voltage etc. In this manner power is feed into the Grid Lines. If your Solar Project Generate Excess Energy to your load, your power will feed in the grid and will get either set off adjustment at the end of billing cycle or get per unit tariff as per rate of policy.