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The average amount of peak sun hours in a day is a different and more useful number as it relates to solar panels than total sun hours. Total sun hours are exactly what you would expect; the total amount of hours that the sun is out during a 24 hour period. Peak sun hours, on the other hand, are the total number of hours in a day where the sunshine is strong enough to to be absorbed and used by solar panels. Sunlight early in the morning or late at night is often not strong enough to count toward peak sun hours. Because of this, total sun hours will always be more than peak sun hours. Looking at the average peak sun hours in Glenwood throughout the year can help you better estimate the amount of solar panels you will need to power your business or home.

Sunlight hits the earth directly at the equator. This is why the equator has a latitude of zero degrees. The latitude of Glenwood is 41.5. Knowing the latitude of Glenwood 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.

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 sun is a great ball of gas that rises and sets every day that the earth rotates while in orbit around the sun. Barring any major disasters this is a very predictable occurance every day. Latitude helps predict this even more, narrowing it down to the minute for sunrise and sunset. But some things aren’t as predictable that will greatly influence the efficiency of solar panels. Weather and cloud coverage for example can greatly diminish peak sun hours on any given day. Thick storm clouds will block a high percentage of the sun's rays, resulting in lower output of your solar panels. Weather needs to be factored into deciding when to use your system, or how much output one expects to get.

In Glenwood the average yearly peak sun hours for a fixed tilt non-tracking solar panel mount is 4.7. 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 6.4 hours if you upgrade to a 2-axis solar panel.