Monday, May 19, 2008

Sun's energy facts

The energy coming from the sun to the Earth's surface is called solar energy. Sun energy is generated in its nucleus mainly through the thermonuclear reaction of hydrogen fusion into helium. In the form of electromagnetic waves this energy is then transmitted from the nucleus towards the surface of the Sun and further on in the surrounding space. The Sun's energy is generated in its core. Gravitational pressures compress and heat the material in the core to over 15 million degrees Celsius or about 27 million degrees Fahrenheit.

Not all of the sun's energy comes to Earth. The sun's energy is emitted in all directions, with only a small fraction being in the direction of the Earth. The average energy of the sun of the whole earth's surface is 2 calories (cal)/ square centimeter (cm2) / minute (min). It is also called the solar constant.

34% of the sun's energy is reflected back into space by snow and clouds. This reflective quality of a planet is called its albedo.

The Sun's energy comes from thermonuclear reactions (converting hydrogen to helium) in the core, where temperatures range from 15 to 25 million degrees.

Only the half -billionth part of the Sun energy reaches the Earth. Only about 5 percent of all available sun energy is conserved as chemical energy in the biomass of plants. A theoretically optimal 80 percent of this energy can be used by the organisms of the next higher trophic level.

Sun energy is clean, inexhaustible and can be transformed into other forms of energy: thermal, electric, chemical, mechanical, etc. The solar energy that energizes the plants goes on to become the fuel that allows animals to live and grow.

The most common forms of renewable energy are solar, wind, water or hydro, biomass and geothermal energy. Renewable energy sources are maintained or replaced by nature after use.

Sunlight can be converted to electricity using photovoltaic (solar electric) panels. This electricity can be used to operate a multitude of electrical appliances. Biomass energy is the sun's energy stored in organic materials such as wood, grains and peat. Wood and peat are both burned to provide heat. Grains can be fermented into ethanol and used as a liquid fuel.

Most of the sun's energy is emitted in a spectrum from 0.15 µm to 4 µm. 41% of it is visible, 9% is uv, 50 % infra-red. The trick to using it as an energy source is being able to convert it from visible light into heat, electricity or other usable form.

The Sun's energy is highly organized and carried by photons. Our Biosphere absorbs this energy and then releases it back to the Universe.

Most of the energy on the earth’s surface comes from the sun. In nature, the sun’s energy affects both living and non-living things. Coal is one way in which the sun's energy is stored temporarily, albeit for millions of years.

During photosynthesis the sun's energy is used to split water molecules, starting a flow of electrons. The energy from this flow of electrons is harnessed and used to make the bonds in organic molecules.

Solar thermal power stations use fields of mirrors to capture the sun's energy as heat to boil water and drive steam turbines.

Most of the sun's energy is produced during nuclear fusion, in which the union of atomic nuclei from two lighter atoms (hydrogen) unite to form a new heavier atom with smaller mass (helium). The "extra" mass is converted into energy.

Thermal conversion is a process whereby the sun's energy is concentrated to heat water and produce steam, which is used to produce electricity. Solar thermal power systems use solar heat energy concentrated using mirrors to drive steam turbines that generate electricity.

Solar electricity collectors use the photovoltaic principle to convert sunlight directly into direct current (DC) electricity. A solar PV collector or module consists of several individual PV cells wired together in a protective container.

The Sun's energy is the principal driver of all of Earth's atmospheric events, from weather patterns in the lower layers, through auroras in the upper layers, to the space weather environment of energetic particles at the altitudes of orbiting satellites.

The Sun's energy is spread around the planet, but is focused on or near the equator. That centerline of the planet is where you will find long sunny days, very little seasonal change, and the warmest ocean waters.

The sun's energy is released from carbon-containing compounds when they are broken down during combustion (burning) or during respiration by animals that have consumed the plants.

The less atmosphere the sun's energy has to pass through, the stronger it will be. It may seem elementary, but solar collectors need to be in the full sun for most of the day.

The sun's energy has been used for thousands of years, in a passive sense, to supply heat to many of humanities most basic needs. Indeed, mankind has cooked with the sun, heated water and created fire.

The source of the sun's energy has challenged scientists for centuries. In the 19th century it was assumed that the sun's energy resulted from its gravitational collapse.

The Sun's energy has a tremendous effect on the Earth's magnetism by way of solar winds. Solar winds are essentially bands of plasma, extremely hot, charged particles, or electrons, of helium and hydrogen, that escape from the Sun's surface.

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