Marseille, France (latitude 43. 3547) is an excellent location for solar photovoltaic (PV) power generation due to its favorable seasonal average daily outputs per kW of installed solar panels: 7. 23 kWh in winter. . With over 2,800 hours of annual sunshine and exceptional irradiation, the Phocaean city offers ideal conditions for quickly achieving profitability with a photovoltaic installation. Do you need Mairie permission to install these solar panels? Not normally. As long as your installation produces an output of less than 3 kWp (the typical output of up to. . The fundamental formula for calculating solar panel wattage is: Wattage = Voltage × Current When applied to solar panels, this can be expressed as: Solar Panel Wattage = Vmp × Imp Where: Vmp represents the voltage at maximum power point, indicating the optimal voltage level at which the panel. . Calculating the solar panel wattage you need for your household is very easy. Found on your utility bill, and solar hours per day – Average hours of direct. . The average energy production for solar systems of different sizes in Marseille is estimated at 1,817 kWh/m2 per year.