Chapel Hill Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Chapel Hill, North Carolina
Lattitude: 35.9271
Sunlight
Fixed Tilt Sunlight Hours: 4.3 hours per day
1-Axis Tilt Sunlight Hours: 5.7 hours per day
2-Axis Tilt Sunlight Hours: 6.9 hours per day
The average peak sun hours of Chapel Hill is a crucial measurable component needed to efficiently implement a solar power system in a home or business. Put simply, peak sun hours are the hours of sunlight a day that are strong enough to be efficiently absorbed by solar panels and eventually turned into usable electricity. Not every minute of sunlight during a day is strong enough to be useful to a solar power system. Think about just minutes after the sunrises, which officially counts towards total hours of sunlight, but is usually too weak to be counted in peak sun hours because the strength of the solar insolation is not strong enough near the horizon to be absorbed and turned into electricity at an efficient rate. Times during the day like this, where the sun is out but not strong enough, are not counted as peak sun hours. In other words, the amount of peak sun hours in a location will theoretically always be less than total sunlight hours for a given day.
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 Chapel Hill is 35.9.
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.
For Chapel Hill the number of average daily peak sunlight hours for a fixed solar panel is 4.3 hours. If you are using a more efficient 1 or 2-axis panel then the number will increase to 5.7 hours for a 1-axis panel and 6.9 hours for a 2-axis panel.