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It goes without saying that throughout the year the amount of sunlight in any given day is going to vary. The time of year and weather will have a strong influence on daily sunshine. Looking at the average amount of peak sunshine hours in a day during an entire year stretch is a valuable exercise when trying to determine the amount and type of solar panels you need to install to power your business or your home. 3.7 peak sun hours means that in Purdy on average there are 3.7 hours a day where the sun is strong enough for solar panels to harness its energy. This number is less than the amount of total sunlight hours in a day because there are times during the day (ex. sunrise and sunset) where the sun is not strong enough to benefit solar panels.

Knowing that the latitude of Purdy is 47.4 can be helpful for understanding total sunlight hour variance. As you approach the equator latitude approaches zero. The closer the latitude is to zero, the more consistent the daily sunlight hours are throughout the year. Total sunlight hour consistency simply makes planning for your solar power needs easier, but it is certainly not a requirement.

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 a fixed mounted solar panel in Purdy, meaning that the solar panel will not track the sun in the sky, once can expect about 3.7 average peak sun hours per day. A 1-axis mount would increase this number to 4.7 hours per day because the panel would be facing the sun throughout the day. A 2-axis system that tracks the sun in the sky every day of the year would get approximately 5.1 hours per day in Purdy.