Cary Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Cary, North Carolina
Lattitude: 35.7815
Sunlight
Fixed Tilt Sunlight Hours: 5.1 hours per day
1-Axis Tilt Sunlight Hours: 6.2 hours per day
2-Axis Tilt Sunlight Hours: 6.4 hours per day
Peak sun hours is arguably the most important number to consider before installing your solar panels. Unlike total sun hours, peak sun hours are calculated by looking at the amount of sunlight hours in a 24 hour period that is strong enough to be absorb by a solar panel. One way to imagine peak sun hours is to think about a solar powered calculator you owned in school. If you covered the solar panel with your finger, or tried to use the calculator in the dark, the calculator would not work. As you slowly exposed the calculator to light the calculator would eventually turn on and be usable. The same is true with peak sun hours; these are the hours that your solar panels receive enough sunlight to work. Looking at the average peak sunlight hours of 5.1 per day can help you determine the amount of solar panels you need to install to power your home or business in Cary, North Carolina.
Although you can easily predict sunrise and sunset hours each day to the minute, looking at latitude can help with your solar planning. The closer you get to the equator the closer your latitude gets to zero. Sunlight hours on the equator are consistent throughout the entire year. Places further from the equator can have large variance in daily sunlight. For example higher latitudes can have very long summer days with lots of sunlight and very dark winters. The latitude of Cary is 35.8.
The sun moves through the sky during the day, and changes positions in the sky throughout the year as the seasons change. A fixed solar panel remains fixed in position during this movement. So, although it is effective in capturing sunlight, a 1-axis or 2-axis panel can be more efficient. A 1-axis panel tracks the sun's movement throughout the day from sunrise to sunset. In addition to that, the 2-axis panel also accounts for the movement 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.
In Cary you can look at the average peak sun hours of a fixed solar panel mount, which will be 5.1 hours. This number iis an estimate based on data of previous years. With a tracking mount in Cary you could theoretically increase the amount of peak sun hours per with a 1-axis mount, and get 6.2 hours, or a 2-axis mount and potentially increase your average to 6.4 hours.