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If you put your solar powered math calculator in your backpack it will turn off from the lack of sunlight needed to power the device. As you slowly open your backpack and begin to let sunlight in, the calculator will eventually turn on when the amount of sunlight is enough to power the calculator. Similarly, peak sun hours refer to the hours of they day where the sunlight is strong enough to power a solar panel. This is different from total sunlight hours, which is simply the amount of hours in a day when there is any sunlight.

Your latitude is an indicator of when the sunrises and sunsets and certain times of the year. If you live near the equator with a latitude of near zero, the sun will rise and set close to the same time all year resulting in consistent total sunlight hours per day. If you live near the poles, the time of sunrise and sunset will vary dramatically with each season, resulting in long days for part of the year and very short days at other times. So, locations closer to the equator will have more consistent amounts of peak sun hours throughout the year than locations closer to the poles.

They type of solar panel you use has an affect on the average peak sunlight hours. Some panels allow for movement, so they can track the sun as it rises in the east and sets in the west, or as the seasons change and the sun's path changes. A fixed panel remains fixed and does not have the ability to rotate, whereas a 1-axis and 2-axis panel can adjust with the sun.

The sun is a great ball of gas that rises and sets every day that the earth rotates while in orbit around the sun. Barring any major disasters this is a very predictable occurance every day. Latitude helps predict this even more, narrowing it down to the minute for sunrise and sunset. But some things aren’t as predictable that will greatly influence the efficiency of solar panels. Weather and cloud coverage for example can greatly diminish peak sun hours on any given day. Thick storm clouds will block a high percentage of the sun's rays, resulting in lower output of your solar panels. Weather needs to be factored into deciding when to use your system, or how much output one expects to get.

We can use previous years of data to estimate the amount of peak sun hours in Union Hall. A fixed tilt mount for example will receive 4.8 average hours per day. For more efficiency for your system in Union Hall you could use a 1-axis tracking mount and increase your daily peak sun average to 5.8 hours, or even further with a 2-axis panel to get an average of 6.4 hours.