Castro Valley Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Castro Valley, California
Lattitude: 37.7095
Sunlight
Fixed Tilt Sunlight Hours: 5.3 hours per day
1-Axis Tilt Sunlight Hours: 7.1 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.
The latitude of the location is important for measuring peak sun hours. The latitude determines how much overall sunlight there will be in a day. With a given latitude, time and date, one can accurately determine when sunrise and sunset will occur. Areas with latitudes closer to the equator will have a more consistent range of solar insolation throughout the year. Whereas areas closer to the poles will have a greater variance during the summer and winter months due to their higher latitudes.
Throughout the day the sun obviously moves throughout the Castro Valley 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.
In Castro Valley the average yearly peak sun hours for a fixed tilt non-tracking solar panel mount is 5.3. 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 7.1 hours if you are using a 1-axis panel, and to 7.7 hours if you upgrade to a 2-axis solar panel.