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, ...

Engineering

Harvesting drinking water from humidity around the clock

Fresh water is scarce in many parts of the world and must be obtained at great expense. Communities near the ocean can desalinate sea water for this purpose, but doing so requires a large amount of energy. Further away from ...

Energy & Green Tech

Chill out: Advanced solar tech runs cooler and lasts longer

Australian photovoltaics researchers have made a 'cool' discovery: Singlet fission and tandem solar cells—two innovative ways to generate solar power more efficiently—also help to lower operating temperatures and keep ...

Engineering

Thermal power nanogenerator created without solid moving parts

As environmental and energy crises become increasingly more common occurrences around the world, a thermal energy harvester capable of converting abundant thermal energy—such as solar radiation, waste heat, combustion of ...

Energy & Green Tech

Advanced facade material for urban heat island mitigation

A joint research team led by Asst. Prof. Jihui Yuan at the Dept. of Architecture and Civil Eng. of Toyohashi University of Technology, in collaboration with Osaka City University, has proposed two analytical models to evaluate ...

Energy & Green Tech

Renewables rescue stability as the grid loses spin

The high-altitude Atacama Desert of northern Chile is a surprising location for scientific insights: Its dry and dusty likeness to Mars makes it ideal for interplanetary testing, and distant worlds are particularly visible ...

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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