Every location on Earth receives sunlight at least part of the year. The amount of solar radiation that reaches any one spot on the Earth's surface varies according to: 1. Geographic location 2. Time of day 3. Season 4. Local landscape 5. Local weather. Because the Earth is round, the sun strikes the surface at different. As sunlight passes through the atmosphere, some of it is absorbed, scattered, and reflected by: 1. Air molecules 2. Water vapor 3. Clouds 4. Dust 5. Pollutants 6. Scientists measure the amount of sunlight falling on specific locations at different times of the year. They then estimate the amount of sunlight falling on regions at the same latitude with similar. Learn more about how solar works and the solar office's photovoltaics and concentrating solar-thermal powerprograms. Home » Solar Information. The solar resource across the United States is ample for photovoltaic (PV) systems because they use both direct and scattered sunlight. Other. The average annual solar radiation arriving at the top of the Earth's atmosphere is about 1361 W/m. This represents the power per unit area of solar irradiance across the spherical surface surrounding the Sun with a radius equal to the distance to the Earth (1 ). This means that the approximately circular disc of the Earth, as viewed from the Sun, receives a roughly stable 1361 W/m at all t.
