Mill Valley Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Mill Valley, California
Lattitude: 37.9085
Sunlight
Fixed Tilt Sunlight Hours: 5.9 hours per day
1-Axis Tilt Sunlight Hours: 7.2 hours per day
2-Axis Tilt Sunlight Hours: 7.6 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 equator has a latitude of zero while Mill Valley has a latitude of 37.9. Any city located on the equator will receive the most sunlight throughout the year because the sunlight arrives at a perpendicular 90 degree angle to the earth at the equator. The further you are from the equator the more your daily sunlight hours can vary.
You will notice that the average peak sun hours for Mill Valley change based on the type of panel being used. The reason for this is quite simple. A fixed panel does exactly what it sounds like, remains fixed in one position at all times. A 1-axis and 2-axis panels have axis that allow them to rotate. The 1-axis rotates with the sun's daily east to west movement while a 2-axis also adjusts for seasonal changes.
Weather is one of the major culprits that will cause inconsistent total peak sun hours for any given day. The sunrise and sunset will always be predictable every day, but the weather is hard to predict and cloud coverage can greatly diminish the efficiency of a solar power system on any given day. On the bright side, a location that is known to have cloudy weather a majority of the year could have unexpectedly more sunny days, so it can go both ways.
We can take the latitude of Mill Valley and use that number to know the amount of total sunlight hours in the region from sunlight to sunset and estimate that with a fixed solar panel, Mill Valley will receive 5.9 average peak sun hours per day. This number can be increased to 7.2 hours by using a 1-axis tracking mount, or 7.6 hours from a 2-axis tracking mount.