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The amount of hours from sunrise to sunset is equal to the total sunlight hours in a 24 hour period. Similarly, peak sun hours are the amount of total sunlight hours in a 24 hour period that are strong enough to provide power from being captured by a solar panel. Not every hour of sunlight delivers the same amount of energy resources. The sunlight at sunrise does not provide as many resources as the amount of sunlight mid-day. Thus, looking at the average peak sunlight hours for Sisters is valuable for calculating your solar needs.

Sunlight hits the earth directly at the equator. This is why the equator has a latitude of zero degrees. The latitude of Sisters is 44.3. Knowing the latitude of Sisters can help you plan for your solar panel setup, as the larger the latitude the more variance you will see throughout the year for total daily sunlight hours.

Throughout the day the sun obviously moves throughout the Sisters sky. The suns position in the sky also changes throughout the year with the seasons. A fixed solar panel does not accommodate for these changes. However, a 1-axis panel rotates and follows the sun’s path during the day. A 2-axis panel both follows the sun’s daily path as well as the seasonal differences

There are more variables than latitude that can change average peak sun hours. Weather patterns and geography will influence solar insolation that reaches your system. Thick grey storm clouds for example will block out a lot of the sun to the point where there may be no peak sun hours in the middle of the day when the sun is usually very powerful. Trees and mountains can deflect the sunlight, so be sure your solar panel is selectively placed.

Since we know the latitude of Sisters we can take the average amount of total sunlight hours and estimate that with a fixed solar panel there would be an average of 4.9 peak sun hours per day. 6.2 hours per day with a 1-axis tracking mount that tracks the sun from sunrise to sunset, and 7.2 hours with a 2-axis tracking mount that tracks the sun everywhere in the sky.