Question

what is solar constant

Answer 1

The solarconstant is a flux density measuring mean solarelectromagneticradiation (solar radiance) per unitarea .it is measured on a surface perpendicular to the rays. one astronomical unit(AU) from the sun (roughly the distance from the sun to the Earth

Answer 2

the rate at which energy reaches the earth's surface from the sun, usually taken to be 1,388 watts per square metre.