Difference between revisions of "Solar Energy"

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[[Portal:Solar|►Back to Solar Portal]]
  
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= Overview<br/> =
  
= Overview<br/> =
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{{#widget:YouTube|id=BtbASIJmsjE|width=600px}}<br/>
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'''Solar energy''' is the radiant light and heat from the sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources account for most of the available renewable energy on earth.
  
'''Solar energy''' is the radiant light and heat from the sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.
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<u>However, only a minuscule fraction of the available solar energy can be used to:</u>
  
<u>Solar energy can be applied to:</u>
 
 
*[[Solar Electric Technologies|Generate Electricity]]
 
*[[Solar Electric Technologies|Generate Electricity]]
*[[Solar Thermal Technologies|Heating]] and [[:Category:Cooling|Cooling]]
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*[[Solar Thermal Technologies|Heating]] and [[Cooling|Cooling]]
*[[Cooking with Sun|Cooking]]
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*[[Cooking with the Sun|Cooking]]
 
*[http://en.wikipedia.org/wiki/Solar_desalination Water Desalination]
 
*[http://en.wikipedia.org/wiki/Solar_desalination Water Desalination]
 
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= Solar Resource Potential =
  
= Solar Radiation at the Earth's Surface<br/> =
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Solar irradiation data is needed at all levels of solar power development, from initial government planning through to large-scale project development or the calculations needed to size smaller systems. In the past such data was provided at a relatively course level from [https://www.nasa.gov/ NASA] and other global providers, but more recently specialist models have been developed to more precisely calculate global horizontal irradiation (GHI) and direct normal irradiation (DNI) using primarily cloud cover data from satellites. A number of firms now offer such data as a commercial service. Based on this, it is possible to calculate average annual power output from a theoretical photovoltaic power plant (PVOUT), taking into account temperature, tilt, and the efficiency of the equipment being used (solar panels and balance of system components).
  
<u>While the solar radiation incident on the earth's atmosphere is relatively constant, the radiation at the earth's surface varies widely due to:</u>
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Solar resource data, including GHI, DNI and PVOUT is now available globally, for free, via the [http://globalsolaratlas.info/ Global Solar Atlas], which is provided by the [http://www.worldbank.org/ World Bank Group]. The same website has downloadable global, regional and country maps available in high resolution.
*Atmospheric effects, including absorption and scattering;
 
*Local variations in the atmosphere, such as water vapour, clouds, and pollution;
 
*Latitude of the location;
 
*Season of the year and the time of day.
 
  
 
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The above effects have several impacts on the solar radiation received at the earth's surface. These changes include variations in the overall power received, the spectral content of the light and the angle from which light is incident on a surface. In addition, a key change is that the variability of the solar radiation at a particular location increases dramatically. The variability is due to both local effects such as clouds and seasonal variations, as well as other effects such as the length of the day at a particular latitude. Desert regions tend to have lower variations due to local atmospheric phenomena such as clouds. Equatorial regions have low variability between seasons.
 
 
Source: [http://pvcdrom.pveducation.org/SUNLIGHT/EARTHSUR.HTM PVCDROM]
 
 
<br/><ref name="http://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-radiation-at-earths-surface">http://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-radiation-at-earths-surface</ref>
 
  
  
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Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of [[Solar Cells and Modules|photovoltaic modules]] (also called photovoltaic panels) and [[Solar Thermal Technologies|solar thermal collectors]] (with electrical or mechanical equipment) to convert sunlight into useful outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.
 
Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of [[Solar Cells and Modules|photovoltaic modules]] (also called photovoltaic panels) and [[Solar Thermal Technologies|solar thermal collectors]] (with electrical or mechanical equipment) to convert sunlight into useful outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.
  
Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.<br/>
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Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.<ref name="http://en.wikipedia.org/wiki/Solar_energy">http://en.wikipedia.org/wiki/Solar_energy</ref><br/>
  
 
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[[Solar Thermal Technologies|Solar thermal technologies]] are harnessing solar energy for thermal energy (heat). Solar thermal technologies comprise flat collectors for low- and medium temperatures and high temperature collectors concentrating sunlight using mirrors and lenses.
 
[[Solar Thermal Technologies|Solar thermal technologies]] are harnessing solar energy for thermal energy (heat). Solar thermal technologies comprise flat collectors for low- and medium temperatures and high temperature collectors concentrating sunlight using mirrors and lenses.
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There are even solar thermal system for cooling purposes that work with adsorption, absorption or desiccant cooling<ref>Green Cooling Initiativ: https://www.green-cooling-initiative.org/network/best-practice-examples/</ref>.
  
 
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== Solar Electric Technologies<br/> ==
 
== Solar Electric Technologies<br/> ==
  
Sunlight can be directly converted into [[Access to Electricity|electricity]] using '''[[Photovoltaic (PV)|photovoltaics]] (PV)''' and various experimental technologies.
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Sunlight can be directly converted into [[Rural Electrification|electricity]] using '''[[Photovoltaic (PV)|photovoltaics]] (PV)''' and various experimental technologies.
  
 
<br/>
 
<br/>
  
<references />
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== OTEC - Ocean Thermal Energy Conversion ==
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[[OTEC - Ocean Thermal Energy Conversion|Ocean Thermal Energy Conversion]] taps into the stored solar energy in the ocean through the difference between the sea-surface temperatures and under 300m depth, which can be harnessed for extracting work through a Rankine cycle.
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*[[Solar Electric Technologies|Solar Electric Technologies]]
 
*[[Solar Electric Technologies|Solar Electric Technologies]]
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*[[Portal:Solar|Solar Portal on energypedia]]<br/>
  
 
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= References<br/> =
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= References =
  
#[http://en.wikipedia.org/wiki/Solar_energy http://en.wikipedia.org/wiki/Solar_energy]
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<references /><br/>
  
 
[[Category:Solar]]
 
[[Category:Solar]]

Revision as of 08:02, 30 August 2021

►Back to Solar Portal

Overview


Solar energy is the radiant light and heat from the sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources account for most of the available renewable energy on earth.

However, only a minuscule fraction of the available solar energy can be used to:


Solar Resource Potential

Solar irradiation data is needed at all levels of solar power development, from initial government planning through to large-scale project development or the calculations needed to size smaller systems. In the past such data was provided at a relatively course level from NASA and other global providers, but more recently specialist models have been developed to more precisely calculate global horizontal irradiation (GHI) and direct normal irradiation (DNI) using primarily cloud cover data from satellites. A number of firms now offer such data as a commercial service. Based on this, it is possible to calculate average annual power output from a theoretical photovoltaic power plant (PVOUT), taking into account temperature, tilt, and the efficiency of the equipment being used (solar panels and balance of system components).

Solar resource data, including GHI, DNI and PVOUT is now available globally, for free, via the Global Solar Atlas, which is provided by the World Bank Group. The same website has downloadable global, regional and country maps available in high resolution.



Solar Technologies and Techniques

Solar energy technologies refer primarily to the use of solar radiation for practical ends. All other renewable energies other than geothermal derive their energy from energy received from the sun.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of photovoltaic modules (also called photovoltaic panels) and solar thermal collectors (with electrical or mechanical equipment) to convert sunlight into useful outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.[1]


Solar Thermal Technologies

Solar thermal technologies are harnessing solar energy for thermal energy (heat). Solar thermal technologies comprise flat collectors for low- and medium temperatures and high temperature collectors concentrating sunlight using mirrors and lenses.

There are even solar thermal system for cooling purposes that work with adsorption, absorption or desiccant cooling[2].


Solar Electric Technologies

Sunlight can be directly converted into electricity using photovoltaics (PV) and various experimental technologies.


OTEC - Ocean Thermal Energy Conversion

Ocean Thermal Energy Conversion taps into the stored solar energy in the ocean through the difference between the sea-surface temperatures and under 300m depth, which can be harnessed for extracting work through a Rankine cycle.



Further Information


References