Joliet Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Joliet, Illinois
Lattitude: 41.5201
Sunlight
Fixed Tilt Sunlight Hours: 4.7 hours per day
1-Axis Tilt Sunlight Hours: 5.8 hours per day
2-Axis Tilt Sunlight Hours: 6.4 hours per day
It goes without saying that throughout the year the amount of sunlight in any given day is going to vary. The time of year and weather will have a strong influence on daily sunshine. Looking at the average amount of peak sunshine hours in a day during an entire year stretch is a valuable exercise when trying to determine the amount and type of solar panels you need to install to power your business or your home. 4.7 peak sun hours means that in Joliet on average there are 4.7 hours a day where the sun is strong enough for solar panels to harness its energy. This number is less than the amount of total sunlight hours in a day because there are times during the day (ex. sunrise and sunset) where the sun is not strong enough to benefit solar panels.
Knowing that the latitude of Joliet is 41.5 can be helpful for understanding total sunlight hour variance. As you approach the equator latitude approaches zero. The closer the latitude is to zero, the more consistent the daily sunlight hours are throughout the year. Total sunlight hour consistency simply makes planning for your solar power needs easier, but it is certainly not a requirement.
Since a fixed solar panel is set in one position it is ideal to place it at an angle that will expose the panel to the most sunlight throughout the year. This angle is generally the same angle of your latitude which is 41.5 for Joliet. You do not need to strategically place a 1-axis or 2-axis panel as much as you do a fixed panel. A 1-axis panel follows the movement of the sun during the day. Additionally, a 2-axis panel also adjusts for the suns various positions in the sky throughout the year.
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.
We can take the latitude of Joliet and use that number to know the amount of total sunlight hours in the region from sunlight to sunset and estimate that with a fixed solar panel, Joliet will receive 4.7 average peak sun hours per day. This number can be increased to 5.8 hours by using a 1-axis tracking mount, or 6.4 hours from a 2-axis tracking mount.