Williamstown Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Williamstown, Massachusetts
Lattitude: 42.7087
Sunlight
Fixed Tilt Sunlight Hours: 4.1 hours per day
1-Axis Tilt Sunlight Hours: 5.4 hours per day
2-Axis Tilt Sunlight Hours: 6.2 hours per day
Peak sun hours are a vital measurement to understand when considering the installation of solar panels. Peak sun hours are not the same as total sunlight hours because not every hour of sunlight during the day has enough strength and solar insolation to qualify as a peak sun hour. The rule of thumb is that a peak sun hour is when the intensity of the sun that is hitting your solar panel is providing at least 1,000 watts per square meter. This is an arbitrary number, but it is a number where most solar panels will be producing an efficient output and not underperforming due to sunshine that is not strong enough or direct enough.
The latitude at the equator of the earth is zero degrees. This is where sunlight strikes the earth most directly. Due to the earth's curved shape, sunlight hits at a various angles depending on location. As latitude increases, the further you are located from the equator and more variance you see in sunlight hours. The latitude of Williamstown is 42.7.
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.
The sunrise and sunset is very predictable every day, but things like cloud coverage and weather are less predictable and vary daily and annually. If a location that is usually very sunny experiences a huge increase in storms and cloud coverage in a given year than the average peak sun hours for that day or year will probably decrease. Tall objects such as trees and buildings can block out the sun during high solar insolation times, so be sure to strategically place your solar panels to get better efficiency.
Since we know the latitude of Williamstown we can take the average amount of total sunlight hours and estimate that with a fixed solar panel there would be an average of 4.1 peak sun hours per day. 5.4 hours per day with a 1-axis tracking mount that tracks the sun from sunrise to sunset, and 6.2 hours with a 2-axis tracking mount that tracks the sun everywhere in the sky.