Home » Solar Turbine » North Carolina » Tramway

Peak sun hours are a vital measurement to understand when considering the installation of solar panels. Peak sun hours are not the same as total sunlight hours because not every hour of sunlight during the day has enough strength and solar insolation to qualify as a peak sun hour. The rule of thumb is that a peak sun hour is when the intensity of the sun that is hitting your solar panel is providing at least 1,000 watts per square meter. This is an arbitrary number, but it is a number where most solar panels will be producing an efficient output and not underperforming due to sunshine that is not strong enough or direct enough.

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 Tramway is 35.4.

A tracking mount will increase the average peak sun hours for a solar power system. Think about a panel that is tracking the sun in the sky vs a panel that is fixed and not moving: you will see a higher efficiency ratio of productions. A 1-axis mount will track the sun from East to West from sunrise to sunset and move on a single axis of rotation. A 2-axis mount will track the Sun from East to West the same as a 1-axis mount would, but it will also track the angle of the sun in the sky as it slowly varies season to season. A 2-axis mount is more necessary in high latitude regions where the angle of the sun in the sky changes dramatically between each equinox.

Although weather predicting technology has greatly evolved over time, it is still a rather unpredictable factor that will affect the amount of peak sun hours your solar power system will receive. Cloudy days for example will usually have lower peak sun hours that a clear sunny day. And areas that usually have more average sunny days per year will probably have higher peak sun hours that areas that are often overcast or stormy.

In Tramway the average yearly peak sun hours for a fixed tilt non-tracking solar panel mount is 4.9. 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 6 hours if you are using a 1-axis panel, and to 6.3 hours if you upgrade to a 2-axis solar panel.