Rock City Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Rock City, Illinois
Lattitude: 42.4131
Sunlight
Fixed Tilt Sunlight Hours: 4.7 hours per day
1-Axis Tilt Sunlight Hours: 5.6 hours per day
2-Axis Tilt Sunlight Hours: 5.7 hours per day
Peak sun hours is one of the most important criteria to examine when considering installing a solar power system. Peak sun hours are different than total sunlight hours in a day because the strength of the radiation of the sun varies throughout the day. For example, during sunrise and sunset the solar insolation from the sun is less powerful than at noon. For a moment of sunshine to be considered a peak sun hour the intensity needs to be at least 1 kilowatt per square meter. This means that a square meter of your solar panel should be receiving 1 kilowatt of energy from the sun. This number is used because it is an amount of light that allows a solar panel to produce output efficiently and not under perform due to lack of sunlight power.
The latitude at the equator of the earth is zero degrees. This is where sunlight strikes the earth most directly. Due to the earth's curved shape, sunlight hits at a various angles depending on location. As latitude increases, the further you are located from the equator and more variance you see in sunlight hours. The latitude of Rock City is 42.4.
You will notice that the average peak sun hours for Rock City change based on the type of panel being used. The reason for this is quite simple. A fixed panel does exactly what it sounds like, remains fixed in one position at all times. A 1-axis and 2-axis panels have axis that allow them to rotate. The 1-axis rotates with the sun's daily east to west movement while a 2-axis also adjusts for seasonal changes.
Looking at latitude, average peak sun hours and various data can obviously help when planning for your solar power needs. The one thing you can never fully account for is changing weather. Storms, rain, cloud coverage all have an impact on solar panel capabilities.
In Rock City you can look at the average peak sun hours of a fixed solar panel mount, which will be 4.7 hours. This number iis an estimate based on data of previous years. With a tracking mount in Rock City you could theoretically increase the amount of peak sun hours per with a 1-axis mount, and get 5.6 hours, or a 2-axis mount and potentially increase your average to 5.7 hours.