This Demonstration compares the maximum incident solar energy per square meter at a given latitudes, in particular, the equator and the North Pole. The model does not consider solar attenuation, weather, shade, altitude, incident angle, or air density. You can select the latitude, hour of the day, and season of the year. The season ranges from 0 to 1 (0 is the summer solstice), latitude ranges from 0 to 90 degrees in the northern hemisphere, and the time of day is on a 24-hour cycle where the point of reference is Greenwich, England on the day of the summer solstice. The vectors normal to the surface and pointing toward the Sun are shown for reference.