Engineering
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.
Apr 5, 2022
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675
Energy & Green Tech
A new device harvests two types of energy during the daytime, making it cool on one end and hot on the other, to generate electricity around the clock. With further improvements, the device could be used in off-grid Internet-of-things ...
Mar 8, 2022
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43
Energy & Green Tech
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, ...
Oct 28, 2021
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5
Energy & Green Tech
A research team at the University of Córdoba has developed and evaluated models for the prediction of solar radiation in nine locations in southern Spain and North Carolina (USA).
Jul 8, 2021
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13
Energy & Green Tech
A team from the Helmholtz-Zentrum Berlin, Ulm University, and Heidelberg University has now investigated how hydrogen can be produced at the South Pole using sunlight, and which method is the most promising. Their conclusion: ...
Jul 2, 2021
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4
Engineering
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 ...
Jun 23, 2021
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1426
Energy & Green Tech
The Earth has its limits, as the climate crisis demonstrates. With the increasing extinction of species and the littering of the oceans (and even space) as a result of human activity, governments and institutions the world ...
May 12, 2021
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61
Energy & Green Tech
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 ...
May 10, 2021
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365
Engineering
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 ...
Mar 31, 2021
1
563
Energy & Green Tech
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 ...
Oct 29, 2020
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3
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
