Solar panels convert sunlight into electrical energy to power a satellite's systems. The solar panels are typically used to charge batteries whilst the satellite is in sunlight. When the satellite passes to the far side of the Earth (into eclipse) the satellite systems will continue to run powered by the on-board batteries. Individually, solar panels provide little power, but large numbers are connected together covering the outside of the satellite or arranged on long arms to increase the surface area that is available to 'catch' sunlight and therefore to provide more electrical energy.
the total solar radiation coming from the sun and all of the sky. it includes the direct beam from the unclouded sun as well as the diffuse radiation arriving, indirectly as scattered or reflected sunlight from the sky and clouds.
is energy from the sun. It is the main energy source for Earth's climate system, heating the surface and driving currents in the oceans and winds in the atmosphere. Ordinary visible sunlight is the most obvious form of solar radiation, but other forms are significant too. For example, see ultraviolet radiation.
Solar radiation is radiant energy emitted by the sun, particularly electromagnetic energy. About half of the radiation is in the visible short-wave part of the electromagnetic spectrum. The other half is mostly in the near-infrared part, with some in the ultraviolet part of the spectrum http://www.grida.no/climate/ipcc_tar/wg1/041.htm#121. the size of this ultraviolet radiation that is not absorbed by the atmosphere produces a suntan or a sunburn on people who have been in sunlight for extended periods of time.