How to select the right solar panel wattage for my needs?

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Understanding Your Energy Needs To select the right solar panel wattage, you need to calculate your daily energy consumption in watt-hours (Wh). Start by listing the appliances you plan to power, their typical usage hours, and their power consumption in watts. For example, a refrigerator might consume 150W, a laptop 65W, and LED lights 10W each. Calculate the total daily Wh consumption by multiplying the power consumption of each appliance by its usage hours and adding them together. For a basic RV setup, a daily consumption of 1000-2000 Wh is typical.
Choosing the Right Solar Panel Wattage A general rule of thumb is to choose a solar panel system that can provide 1.5 to 2 times your daily energy requirements to account for inefficiencies in the system, such as inverter losses, and variability in solar irradiance. For a 1000 Wh daily consumption, you would need a solar panel system that produces at least 1500-2000 Wh per day. To determine the required solar panel wattage, divide the daily energy requirement by the system’s efficiency, which is typically around 0.75 for a well-designed system. For example, a 2000 Wh daily requirement would translate to a 2667 W (2000 Wh / 0.75) solar panel system.
Considerations for Inverter and Battery Bank When selecting the solar panel wattage, also consider the inverter and battery bank capacity. A larger battery bank can store excess energy generated by the solar panels during the day for use at night or on cloudy days. Choose an inverter that matches the battery bank capacity and can handle the maximum power point tracking (MPPT) of the solar panels. For a standard 12V battery bank, choose an inverter with a DC input rating that matches the solar panel array’s maximum power point tracking (MPPT) rating.