Engineering

Thin-film technologies for the energy transition

Glass facades characterize modern architecture. While solar radiation serves to support heating in winter, the building interior heats up in summer and requires active cooling. Smart windows can regulate the solar radiation ...

Electronics & Semiconductors

Scientists decide how to prove out perovskite panels for space power

Perovskites, which have shown enormous potential as a new semiconductor for solar cells, are gaining attention as well as a potential next-generation technology to also power spacefaring missions. As scientists around the ...

Engineering

Solar cell keeps working long after sun sets

About 750 million people in the world do not have access to electricity at night. Solar cells provide power during the day, but saving energy for later use requires substantial battery storage.

Energy & Green Tech

New model better predicts solar cell output power in all weather

The world is in dire need of a large-scale transition away from fossil fuels and towards sustainable energy sources to prevent an environmental crisis. Thanks to recent advances in various scientific and engineering disciplines, ...

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Sunlight

Sunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the nights are shorter or non-existent. In the winter at the poles the nights are longer and for some periods of time, sunlight may not occur at all. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation. Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth. The World Meteorological Organization defines sunshine as direct irradiance from the Sun measured on the ground of at least 120 watts per square metre.

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared, visible, and ultra-violet light. Bright sunlight provides luminance of approximately 100,000 candela per square meter at the Earth's surface.

Sunlight is a key factor in photosynthesis, a process crucially important for life on Earth.

This text uses material from Wikipedia, licensed under CC BY-SA