Des Plaines Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Des Plaines, Illinois
Lattitude: 42.0343
Sunlight
Fixed Tilt Sunlight Hours: 4.1 hours per day
1-Axis Tilt Sunlight Hours: 5.7 hours per day
2-Axis Tilt Sunlight Hours: 6.6 hours per day
If you put your solar powered math calculator in your backpack it will turn off from the lack of sunlight needed to power the device. As you slowly open your backpack and begin to let sunlight in, the calculator will eventually turn on when the amount of sunlight is enough to power the calculator. Similarly, peak sun hours refer to the hours of they day where the sunlight is strong enough to power a solar panel. This is different from total sunlight hours, which is simply the amount of hours in a day when there is any sunlight.
Your latitude is an indicator of when the sunrises and sunsets and certain times of the year. If you live near the equator with a latitude of near zero, the sun will rise and set close to the same time all year resulting in consistent total sunlight hours per day. If you live near the poles, the time of sunrise and sunset will vary dramatically with each season, resulting in long days for part of the year and very short days at other times. So, locations closer to the equator will have more consistent amounts of peak sun hours throughout the year than locations closer to the poles.
They type of solar panel you use has an affect on the average peak sunlight hours. Some panels allow for movement, so they can track the sun as it rises in the east and sets in the west, or as the seasons change and the sun's path changes. A fixed panel remains fixed and does not have the ability to rotate, whereas a 1-axis and 2-axis panel can adjust with the sun.
Peak sun hours are greatly affected by weather patterns. Cloud coverage is a huge factor in peak sun hours per day because heavy cloud coverage will diminish the power of the solar insolation. You can use historical climate data to estimate average cloud and weather coverage, but it will obviously vary slightly from year to year.
In Des Plaines the average yearly peak sun hours for a fixed tilt non-tracking solar panel mount is 4.1. This is for a fixed panel mounted at an angle that is equal to the latitude of the location for the entire year. The amount of peak sun hours increases to 5.7 hours if you are using a 1-axis panel, and to 6.6 hours if you upgrade to a 2-axis solar panel.