Portland Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Portland, Texas
Lattitude: 27.8858
Sunlight
Fixed Tilt Sunlight Hours: 5.1 hours per day
1-Axis Tilt Sunlight Hours: 7 hours per day
2-Axis Tilt Sunlight Hours: 7.7 hours per day
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.
Knowing that the latitude of Portland is 27.9 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.
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.
In Portland you can look at the average peak sun hours of a fixed solar panel mount, which will be 5.1 hours. This number iis an estimate based on data of previous years. With a tracking mount in Portland you could theoretically increase the amount of peak sun hours per with a 1-axis mount, and get 7 hours, or a 2-axis mount and potentially increase your average to 7.7 hours.