Solar energy facts for kids

Kids Encyclopedia Facts
(Redirected from Solar power)
Sun920607
At the equator, the Sun provides approximately 1000 watts per square meter on Earth's surface.
Insolation
The top diagram shows how the strength of sunlight is less nearer the Earth's poles. The lower map shows how much solar energy hits the Earth's surface after clouds and dust have reflected and absorbed some solar energy.
SolarGIS-Solar-map-Europe-en
Solar Radiation Map: Global Horizontal Irradiation in Europe

Solar energy is the energy that is in sunlight. It has been used for thousands of years in many different ways by people all over the world. As well as its traditional human uses in heating, cooking, and drying, it is used today to make electricity where other power supplies are absent, such as in remote places and in space. It is becoming cheaper to make electricity from solar energy and in many situations it is now competitive with energy from coal or oil. A solar cooker can be used for cooking food. Solar energy is also called "Heat Trapper" as it is the automatic, non-mechanical, sun ray trapper. This Sun trapper like devices were used by soldiers during WWII for heat requirements in the army and enemy directions.

Energy use

Solar energy is used today in a number of ways:

Energy from the Sun

After passing through the Earth's atmosphere, most of the Sun's energy is in the form of visible light and infrared light radiation. Plants convert the energy in sunlight into chemical energy (sugars and starches) through the process of photosynthesis. Humans regularly use this store of energy in various ways, as when they burn wood or fossil fuels, or when simply eating plants, fish and animals.

Solar radiation reaches the Earth's upper Earth's atmosphere with the power of 1366 watts per square meter (W/m2). Since the Earth is round, the surface nearer its poles is angled away from the Sun and receives much less solar energy than the surface nearer the equator.

At present, solar cell panels convert, at best, about 15% of sunlight hitting them into electricity. The dark disks in the third diagram on the right are imaginary examples of the amount of land that, if covered with 8% efficient solar panels, would produce slightly more energy in the form of electricity than the world needed in 2003.

Types of technologies

PV Soundless Freising
Solar energy absorbing panels on the sound barrier next to the Munich airport.

Many technologies have been developed to make use of solar radiation. Some of these technologies make direct use of the solar energy (e.g. to provide light, heat, etc.), while others produce electricity.

Solar power plants

Solar power plants convert sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics converts light into electric current using the photoelectric effect.

Photovoltaics

World's largest photovoltaic power stations
Photovoltaic power station Country Site co-ordinates Nominal
power
Production
(Annual
GW·h)
Notes and references
Topaz Solar Farm USA &&&&&&&&&&&&0500.&&&&&0500 installed capacity as of June 2014.
Desert Sunlight Solar Farm USA &&&&&&&&&&&&0500.&&&&&0500 Commissioned since November 2013 toward final capacity 550 MW
Longyangxia Dam Solar Park China &&&&&&&&&&&&0320.&&&&&0320 Completed December 2013
Solar Star I and II USA &&&&&&&&&&&&0309.&&&&&0309 Under construction, 579MW when completed
California Valley Solar Ranch USA &&&&&&&&&&&&0292.&&&&&0292 399 First 130MW connected Feb 2013.
Agua Caliente Solar Project USA &&&&&&&&&&&&0290.&&&&&0290 626 completed April 2014
Antelope Valley Solar Ranch USA &&&&&&&&&&&&0266.&&&&&0266 230 MWAC. Has received government loan guarantee

Concentrated solar thermal

Rank

View of Ivanpah Solar Electric Generating System from Yates Well Road, San Bernardino County, California. The Clark Mountain Range can be seen in the distance.
Rank Station Country Location Capacity (MW) Ref
1 Ivanpah  United States 377
2 SEGS  United States 354
3 Solana  United States 280
4 Genesis  United States 250
5 Solaben  Spain 200
6 Solnova  Spain 150
6 Andasol  Spain 150
6 Extresol  Spain 150
9 Palma del Rio  Spain 100
9 Manchasol  Spain 100
9 Valle  Spain 100

Solar cooker

Cuisson-solaire
Solar cooking

Solar cooking uses the Sun as the source of energy instead of standard cooking fuels such as charcoal, coal or gas. Solar cookers are an inexpensive and environmentally sound alternative to traditional ovens. They are becoming widely used in areas of the developing world where deforestation is an issue, financial resources to purchase fuel are limited, and where open flames would pose a serious risk to people and the environment

Solar heater

Jablunkov, dům se solárními panely
House with solar panels for heating and other needs in Jablunkov, Czech Republic.

The Sun may be used to heat water instead of electricity or gas. There are two basic types of active solar heating systems based on the type of fluid — either liquid or air — that is heated in the solar energy collectors. (The collector is the device in which a fluid is heated by the Sun.)

Liquid-based systems heat water or an antifreeze solution in a "hydronic" collector, whereas air-based systems heat air in an "air collector." Both air and liquid systems can supplement forced air systems.

Solar cells

4inchcell
Photo of 4 inch by 4 inch cell.

Solar cells can be used to generate electricity from sunlight. It is a device that converts light energy into electrical energy. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the light source is unspecified.

Solar cells have many applications. They have long been used in situations where electrical power from the grid is unavailable, such as in remote area power systems, Earth-orbiting satellites and space probes, consumer systems, e.g. handheld calculators or wrist watches, remote radiotelephones and water pumping applications.

Related pages

Images for kids


Solar energy Facts for Kids. Kiddle Encyclopedia.