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The Solar Portal

The Sun photographed by the Atmospheric Imaging Assembly (AIA 304) of NASA's Solar Dynamics Observatory (SDO).
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.

Often Solar powered electrical generation relies on heat engines and photovoltaics. Solar energy's uses are limited by human ingenuity, and the finite resourced to build the sys. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes.To harvest the solar energy, the most common way is to use solar panels.

Solar technologies are characterized as either passive solar or active solar, depending on the way the energy is captured, converted and distributed. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the suns seasonal orientation, selecting materials with favorable thermal mass, which will capture and radiate solar energy, light dispersing properties that will disperse light energy, or designing spaces that naturally circulate solar heated air.

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Selected page

Earth bound radiation losses
The solar resource. Solar energy is the source of all energy on earth, available to us in a number of derivatives. Plant matter for example, which relies on solar energy for nutrition, experiences natural compression and decomposition over millions of years to form the the fossil fuels we use today for electrical generation and transportation. Other examples of this can be seen in use of biomass for fuel or the harvesting of wind energy which is reliant on solar heated air for the formation of currents.

We are also able to utilize the solar resource directly. Solar thermal technologies take advantage of this resource to heat a working fluid that can transfer energy to an air stream or water for domestic or commercial use. Solar Photovoltaic or PV devices exploit various materials (principally Silicon) that experience sub-atomic variations when exposed to solar energy in order to induce an electric current. Both solar PV and thermal technologies provide a useful source of energy with little to no moving parts, no pollution and very little embodied energy.

In order to effectively design a solar energy system, an understanding of the available solar resource at the location of interest is required. All of the energy available on Earth is derived from the sun. We can model the sun's surface as blackbody. At a specific temperature, approximately 5777K for the sun, a blackbody emits energy with a unique radiation spectrum. The spectrum is divided into three broad ranges classified as ultraviolet, visible and infrared which transmit radiation at varying intensities. The highest intensities are found within the visible spectrum, peaking at a wavelength close to 0.5um. Averaged over the entire surface, the power density of the sun is found to be approximately 63 x 10 W/m2.

Aleiha's parabolic solar cooker

A very hot (400 °F) parabolic solar cooker. Made from an reclaimed satellite dish using bicycle powered tools.

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Selected topics (Book)

Greenhouses: Construction of an Affordable Greenhouse · Humboldt greenhouse gallery

Passive solar design: Parras passive solar design gallery · Thermal mass · Thermosiphon

Photovoltaics: Energy · System energy · Grid connection · Holographic solar · Humbolt gallery · Maintenance · Panels · Parras gallery · Refrigeration · Vaccine refrigeration · Test field · Troubleshooting · Rural lighting · Water pumping

Solar cooking: Analysis of a solar cooker  · and development · and health

Solar dehydrating: Food Drying with Superheated Steam · Solar drying in Uganda

Solar distillation: Compound parabolic concentrator · Effect of water on light transmission of glass · Improving Basin Solar Stills · Solar distillation TB · Solar fuel alcohol distillation

Solar energy: Open Solar Outdoors Test Field · Smart windows · The solar resource

Solar hot water: DIY solar thermal collectors · Installation and Design Principles · System types

Solar power: Heliostats · Solar thermal energy

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