Bristol Solar Power Information & Peak Sun Hours
Solar Green Energy Summary for Bristol, Rhode Island
Lattitude: 41.6771
Sunlight
Fixed Tilt Sunlight Hours: 4.6 hours per day
1-Axis Tilt Sunlight Hours: 5.7 hours per day
2-Axis Tilt Sunlight Hours: 5.8 hours per day
Peak sun hours is one of the most important criteria to examine when considering installing a solar power system. Peak sun hours are different than total sunlight hours in a day because the strength of the radiation of the sun varies throughout the day. For example, during sunrise and sunset the solar insolation from the sun is less powerful than at noon. For a moment of sunshine to be considered a peak sun hour the intensity needs to be at least 1 kilowatt per square meter. This means that a square meter of your solar panel should be receiving 1 kilowatt of energy from the sun. This number is used because it is an amount of light that allows a solar panel to produce output efficiently and not under perform due to lack of sunlight power.
If you open the newspaper in the morning or watch the weather channel on the news you can get an accurate prediction of sunrise and sunset each day for Bristol. However, still knowing that the latitude of Bristol is 41.7 can be a helpful number for your solar panel setup and planning. The closer your latitude is to zero the closer you are to the equator. At the equator you find the most consistent total sunlight hours throughout any given day of the year. As your latitude increases you can see larger discrepancies of daily sunlight hours during the year. For example, having very long summer days and very short and dark winter days
They type of solar panel you use has an affect on the average peak sunlight hours. Some panels allow for movement, so they can track the sun as it rises in the east and sets in the west, or as the seasons change and the sun's path changes. A fixed panel remains fixed and does not have the ability to rotate, whereas a 1-axis and 2-axis panel can adjust with the sun.
Although weather predicting technology has greatly evolved over time, it is still a rather unpredictable factor that will affect the amount of peak sun hours your solar power system will receive. Cloudy days for example will usually have lower peak sun hours that a clear sunny day. And areas that usually have more average sunny days per year will probably have higher peak sun hours that areas that are often overcast or stormy.
For a fixed mounted solar panel in Bristol, meaning that the solar panel will not track the sun in the sky, once can expect about 4.6 average peak sun hours per day. A 1-axis mount would increase this number to 5.7 hours per day because the panel would be facing the sun throughout the day. A 2-axis system that tracks the sun in the sky every day of the year would get approximately 5.8 hours per day in Bristol.