How Much Energy Does A Solar Panel Produce? | EnergySage
Most solar panels have cells that can convert 17-23% of the sunlight that hits them into usable solar energy.
A 100-watt panel that operates at full capacity for an average of four hours of sunlight produces 0.4 kWh. A kilowatt-hour measures how much electrical the panel can supply. It stands for one kilowatt (or 1,000 watts) of power for one hour.
A 400-watt panel can generate roughly 1.6–2.5 kWh of energy per day, depending on local sunlight. To cover the average U.S. household's 900 kWh/month consumption, you typically need 12–18 panels. Output depends on sun hours, roof direction, panel technology, shading, temperature and age.
In good weather, you can expect around 300–600Wh (watt-hours) per day from a 100W panel. That translates to about 3–6 hours of “peak sun,” which varies by location and season. For example, according to data from NREL (National Renewable Energy Laboratory) and the PVWatts database on average daily sunlight hours:
About 97% of solar panels quoted on the EnergySage Marketplace in 2025 are 400 to 460 watts—expect to see panel outputs in this range in your quotes. Your panels' actual output will depend on your roof's shading, orientation, and hours of sun exposure. The efficiency and size of your solar panels drive their power output.
PDF version includes complete article with source references. Suitable for printing and offline reading.
Download detailed product specifications, case studies, and technical data for our off-grid PV containers and mobile energy storage solutions.
15 Innovation Drive
Johannesburg 2196, South Africa
+27 87 702 3126
Monday - Friday: 7:30 AM - 5:30 PM SAST