Solar Radiation and Energy

Conventional sources of energy include coal, petroleum, natural gas, wood etc. Carbon is their main constituent.

When plants use solar energy for the synthesis of their food, only a small part of solar energy used,  rest of the part of this energy evaporate from the surface of leaves by the process of transpiration and due to its high latent heat. It is the best material for disposing excess  solar energy.

The land has compactly arranged molecules through which conduction takes place and as it is an insulator heat, the heat remains on the surface of the earth i.e. land whereas water has loosely packed molecule heat is transferred by convection and thus it takes a longer time to heat up. Also, water has a higher specific heat capacity, meaning that it requires more energy to heat water to the same temperature as a piece of land. Water also reflects more incoming radiation. The land is dark, rough, and solid, which all contribute to the absorption of the radiation. Unlike water, the land is unable to retain heat for as long as water.

The sun offers the most abundant, reliable and pollution-free power in the world.However, problems with solar energy, namely the expensive cost and inconsistent availability, have prevented it from becoming a more utilised energy source.

Chemical energy is stored in the bonds that connect atoms with other atoms and molecules with other molecules. Because chemical energy is stored, it is a form of potential energy. When a chemical reaction takes place, the stored chemical energy is released. Chemical Energy - is really a form of potential energy and is the energy stored in food or chemical combinations. Radiant Energy - is a combination of heat and light energy.

Solar luminosity is defined as the total amount of energy emitted by a star per unit time. Luminous flux and intensity relate to human perception of light, not total energy emission.

Candle, sun and bulb emit light radiation when they glow, so they are the sources of light. But black body do not emit light and thus is is not a source of light.

Sun tanning is a chemical change as vitamin D and melanin are produced during tanning. As new products are formed during sun tanning, it is considered to be a chemical change.

A solar cooker is a device which uses the energy of direct sunlight to heat or cook. A mirrored surface with high specular reflectivity is used to concentrate light from the sun on to a small cooking area. Depending on the geometry of the surface, sunlight can be concentrated by several orders of magnitude producing temperatures high enough to melt salt and smelt metal. 

There are two primary means of achieving desalination using solar energy, through a phase change by thermal input, or in a single phase through mechanical separation. Phase change (or multi-phase) can be accomplished by either direct or indirect solar distillation. Single phase is done by the use of photovoltaic cells to produce electricity to drive pumps.

Photons generated in the Sun's core undergo a random walk, colliding repeatedly with dense plasma particles, which significantly delays their journey to the surface.

Solar energy is the primary source for wind energy (via heating differences), light energy (direct radiation), and heat energy (thermal absorption).

The Sun generates energy primarily through nuclear fusion, where hydrogen nuclei fuse to form helium, releasing vast amounts of energy.

Infrared radiation plays an important role in maintaining the earth's warmth or average temperature through the greenhouse effect. It is the part of the spectrum that is detected by the human eyedetected by the human eye.