A 100W solar panel converts approximately 100 watts, under optimal conditions, which translates to 0. 1 kilowatts per hour of electricity generated. In ideal situations, it can yield around 300-400 watt-hours daily, depending on sunlight exposure and geographical location. But pay attention to this: this "100W" description is the panel's maximum rating, often measured under Standard Test. Quick answer: A modern 400W solar panel produces about 1. residential median of 5 peak sun hours. A 10 kW system produces about 42 kWh/day. Expect 400-500Wh per day in good conditions. Your Battery (for charging estimate) * Actual output varies by location, season, panel angle.