Watts Per Square Meter Solar Panel
On a clear day with high solar irradiance, a square meter of efficient solar panels can generate around 150-250 watt-hours (Wh) of energy in an hour. It translates to
On a clear day with high solar irradiance, a square meter of efficient solar panels can generate around 150-250 watt-hours (Wh) of energy in an hour. It translates to approximately 1.5-2.5 kWh per day. Remember that this is a rough estimate and can vary based on factors such as panel efficiency, geographic location, and weather conditions.
Solar panel watts per square meter (W/m) measures the power output of a solar panel based on its size. Compare solar panels to see which generates most electricity per square meter. A higher W/m value means a solar panel produces more power from a given area. This can help you determine how many solar panels you need for your energy needs.
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.
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.
Get technical specifications, ROI analysis tools, and pricing information for our BESS integration and energy storage solutions.
Av. de la Innovación 15
28042 Madrid, Spain
+34 91 133 2769
Monday - Friday: 9:00 AM - 6:00 PM CET