Peak sun hours are the specific duration during which the sun’s potency reaches an average of 1,000 watts of photovoltaic power and that too for per square meter. It is important to note that peak sun hour is not equivalent to one hour on the clock but rather a measure of the period when the sun’s glimmer is most potent in a given geographical area. This measurement signifies the optimal timeframe for maximizing electricity generation using solar panels.
Scientifically speaking, one peak sun hour corresponds to an irradiance level of 1,000 W/m² (or 1 kW/m²) of sunlight per hour.
These sun hours do not correspond to the hours between sunrise and sunset; rather, they represent a specific duration during which a particular area receives the highest solar insolation, indicating the peak intensity of the sun for that period.
Peak Sun Hours by Region in the USA
State | Average Daily Peak Sun Hours |
Alabama | 4.4-5 |
Alaska | 2-3 |
Arizona | 5-6 |
Arkansas | 4.4-4.7 |
California | 4.1-6 |
Colorado | 4.2-5.4 |
Connecticut | 3.9-4.1 |
Delaware | 4.1-4.3 |
Florida | 4.8-5.4 |
Georgia | 4.4-4.9 |
Hawaii | 3.5-6.6 |
Idaho | 3.4-4.8 |
Illinois | 3.9-4.4 |
Indiana | 3.9-4.3 |
Iowa | 3.9-4.3 |
Kansas | 4.3-5.1 |
Kentucky | 4-4.4 |
Louisiana | 4.6-5.1 |
Maine | 3.4-3.9 |
Maryland | 3.8-4.4 |
Massachusetts | 3.7-4.1 |
Michigan | 3.5-3.9 |
Minnesota | 3.5-4 |
Mississippi | 4.5-4.9 |
Missouri | 4.2-4.5 |
Montana | 3.4-4.4 |
Nebraska | 4.1-4.7 |
Nevada | 4.6-5.8 |
New Hampshire | 3.4-3.9 |
New Jersey | 3.9-4.3 |
New Mexico | 5-6 |
New York | 3.5-4.1 |
North Carolina | 4.2-4.7 |
North Dakota | 3.7-4.1 |
Ohio | 3.7-4.1 |
Oklahoma | 4.5-5.3 |
Oregon | 3.3-4.8 |
Pennsylvania | 3.6-4.1 |
Puerto Rico | 4.6-5.9 |
Rhode Island | 3.9-4.1 |
South Carolina | 4.5-4.9 |
South Dakota | 3.9-4.5 |
Tennessee | 4.1-4.5 |
Texas | 4.6-5.9 |
Utah | 4.4-5.5 |
Vermont | 3.4-3.8 |
Virginia | 4-4.5 |
Washington | 2.8-4.4 |
Washington DC | 4.1-4.2 |
West Virginia | 3.8-4.2 |
Wisconsin | 3.6-4 |
Wyoming | 3.9-4.9 |
Please note that these values represent the average daily peak sun hours and may vary depending on specific locations within.
Also See: Understanding the Specifications of Solar Panels and How to Read Them
How Many Peak Sun Hours Do You Need to Go Solar?
The minimum requirement for a location suitable for solar energy production in the United States typically has at least four peak sun hours. Locations meeting or exceeding this threshold are favorable for generating substantial solar power. However, it is important to note that even areas with fewer peak hours can still benefit from solar energy adoption. Various other crucial factors influence the feasibility of residential solar installations, including electricity rates and the availability of incentives at both the federal and state levels, such as the 30% solar tax credit. You can explore the available resources to determine the specific local, state, and utility solar incentives applicable to your area. For instance, individuals residing in regions with below-average peak hours but high utility rates and favorable net metering policies can realize significant cost savings by embracing solar energy.
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