Home » Solar Turbine » South Dakota » Watertown

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.

Sunlight hits the earth directly at the equator. This is why the equator has a latitude of zero degrees. The latitude of Watertown is 44.9. Knowing the latitude of Watertown can help you plan for your solar panel setup, as the larger the latitude the more variance you will see throughout the year for total daily sunlight hours.

Although most things are out of our control, like the sunrise, sunset or the weather, we can control the angle and the kind of mount we use for a solar panel. The angle of the solar panel, if using a fixed mount, should generally be around the angle that is equal to the latitude of the location to maximize output. In the northern hemisphere, panels angles should be lower in the winter months and higher in the summer months As a fixed mount is set, it is ideal to place it at an angle that will capture the most sunlight during the year. A 1-axis tracking solar mount will track the sun across the sky from sunrise to sunset, but the angle will remain the same throughout the day. A 2-axis solar mount will track the sun throughout the day from East to West, but the angle will also change automatically as the seasons change and the angle of the sun in the sky changes. Thus, a 2-axis will have a higher rating of peak sun hours compared to the 1-axis or fixed.

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.

In Watertown 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 5.8 hours if you are using a 1-axis panel, and to 6.5 hours if you upgrade to a 2-axis solar panel.