The Earth receives 174,000 terawatts (TW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. Most people around the world live in areas with insolation levels of 150 to 300 watts per square meter or 3.5 to 7.0 kWh/m2 per day. COUNT 7
QSN1 How many terawatts of solar radiation does the Earth receive? ANS1 174,000 QSN2 What percentage of solar radiation is reflected back by the atmosphere? ANS2 30% QSN3 The areas that people live in typically receive what range of kWh/m2 per day? ANS3 3.5 to 7.0 QSN4 How many terrawatts of radiation does the earth receive? ANS4 174,000 QSN5 How much of the solar radiation is reflected back into space? ANS5 Approximately 30% QSN6 What are the insolation levels of most populated areas? ANS6 150 to 300 watts per square meter or 3.5 to 7.0 kWh/m2 per day QSN7 Where is the solar radiation not reflected back to space absorbed? ANS7 clouds, oceans and land masses