Radiation heat transfer is the process by which thermal energy exchanged between two surfaces obeying the law of electromagnetic so it does not require any medium and can be used for the transfer of heat in a vacuum. The light or heat from the sun reaches our planet earth because of the radiation and also it is the most potent medium of heat transfer. Let us take an example of radiation, in winter, when we sit near the fire we never get burned but we feel the heat coming from that fire and its warmth that is radiation.
How radiation is different from conduction and convention?
As we know that construction and convection both need matter to transfer heat while radiation is a method of transfer of heat that does not rely on any contact between the heat source and heated object. Radiation is nothing but a form of energy transport consisting of electromagnetic waves that travel at the speed of light in which no mass is exchanged and no medium is required. Objects only create radiation when high energy electrons in a higher atomic level fall down to the lower levels and the fall of the energy and the energy lost is emitted as light or electromagnetic radiation but only on one condition that is if the absorption of energy is less than the emission of energy the temperature of an object falls. In radiation molecules and atoms of the medium can absorb, reflect and transmit the energy.
Solar cells a new way of radiation energy.
As we discussed above that radiation need no material to reflect, absorb and transmit the energy in any surface this gives a whole new idea about using solar panels as they create heat, light and sufficient energy to be provided at the place of electricity or use of natural energy sources can be forgiven or can be reduced. Solar cells or photovoltaic cells work to convert the energy of light into electricity by a process called the photovoltaic effect. This is a whole new scientific process by which light is selected by charges and creates a high voltage to produce electricity. The use of solar cells has risen in recent years as people are getting aware by the fact that natural resources are exploited much and these kinds of energies can also be created which are somehow natural but redesigned by humans for their useful purpose.