Solar Constant Calculator

Calculates Power and area with the solar constant, where the Sun is shining on the Earth's surface. The solar constant tells, with which intensity the Sun on average shines vertically on an area on Earth. Its value is 1361 watts per square meter. Hereby, Earth's atmosphere isn't taken into account, the practical value of the incoming radiation changes with weather and other atmospheric conditions. When the air is clear, about 75 percent of the radiation gets to the ground, 25 percent are reflected. Light clouds reflect about half of the radiation

Calculate with

Solar constant GSC:W/m²
Incoming radiation:W/m²


Round to    decimal places.

At solar constant, reflection and incoming radiation, from two values the third can be calculated. From solar constant or incoming radiation, when entering area, power will be calculated and when entering power, area will be calculated.

Example: at 40 percent reflection, 20 square meters on Earth will be irradiated with 16.3 kilowatts by the Sun, if the Sun shines vertically to this area.

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