Energy & Green Tech

A new way to provide cooling without power

MIT researchers have devised a new way of providing cooling on a hot sunny day, using inexpensive materials and requiring no fossil fuel-generated power. The passive system, which could be used to supplement other cooling ...

Energy & Green Tech

Stacking solar cells method could be electricity gain

Is there a way to stack solar cells and convert more of the energy in sunlight into electricity? Not only has a company developed a method, but, as a headline said Wednesday in MIT Technology Review, the approach could make ...

Energy & Green Tech

Chile inaugurates Latin America's first thermosolar plant

Chile on Tuesday inaugurated Latin America's first-ever thermosolar energy plant, a vast complex dubbed Cerro Dominador in the Atacama desert that gives a boost to the country's quest for carbon-neutrality by 2050.

Energy & Green Tech

Holograms increase solar energy yield

The energy available from sunlight is 10,000 times more than what is needed to supply the world's energy demands. Sunlight has two main properties that are useful in the design of renewable energy systems. The first is the ...

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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