Herrin, Illinois presents a moderately favorable location for year-round solar energy generation, though with significant seasonal variations typical of the Northern Temperate Zone climate.

Seasonal Solar Performance

The solar energy output at this location shows a clear seasonal pattern that reflects the area's continental climate. Summer provides the strongest performance at 6.65 kWh per day per installed kilowatt, making it the peak season for solar generation. Spring follows as the second-best season with 5.49 kWh per day per kW, offering excellent solar potential during the longer days and moderate weather conditions. Autumn sees a notable drop to 4.13 kWh per day per kW as daylight hours decrease and weather patterns become more variable. Winter presents the most challenging conditions for solar generation, producing only 2.42 kWh per day per kW, which is less than half of the summer output.

Optimal Installation Configuration

For maximum year-round energy production at Herrin, Illinois, solar panels should be installed at a fixed tilt angle of 33 degrees facing south. This angle has been calculated to optimize total annual solar output by accounting for the sun's changing position throughout the year and weighting the angles based on actual solar potential at this latitude.

Local Factors Affecting Solar Production

Several environmental and weather factors in the Herrin area can significantly impact solar panel performance and should be considered during installation planning. Snow and Ice Accumulation: Winter weather can cause snow and ice to accumulate on solar panels, blocking sunlight and reducing energy output. Installing panels at the recommended 33-degree tilt angle helps promote natural snow shedding. Additionally, ensuring adequate spacing between panel rows prevents snow from one panel casting shadows on panels below. Severe Weather Events: The region experiences thunderstorms, high winds, and occasional severe weather that can damage solar installations. Using properly rated mounting systems designed for local wind loads and installing panels with appropriate structural support helps ensure system durability. Humidity and Moisture: The area's climate includes periods of high humidity and moisture, which can affect electrical connections and panel performance over time. Choosing components with appropriate weatherproofing ratings and ensuring proper drainage around ground-mounted systems helps prevent moisture-related issues. Agricultural Dust and Particulates: Being located in an agricultural region, airborne dust and particulates from farming activities can accumulate on panel surfaces, reducing light transmission. Regular cleaning schedules and selecting panel surfaces that shed dirt more easily can help maintain optimal performance. Tree Coverage and Vegetation: The area's natural vegetation and agricultural landscape may include trees that could shade solar installations. Careful site selection, proper system placement, and occasional tree trimming can minimize shading impacts throughout the year.

Note: The Northern Temperate Zone extends from 35° latitude North up to 66.5° latitude.

So far, we have conducted calculations to evaluate the solar photovoltaic (PV) potential in 4253 locations across the United States. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.

Link: Solar PV potential in the United States by location

Solar output per kW of installed solar PV by season in Herrin

Seasonal solar PV output for Latitude: 37.7992, Longitude: -89.0227 (Herrin, United States), based on our analysis of 8760 hourly intervals of solar and meteorological data (one whole year) retrieved for that set of coordinates/location from NASA POWER (The Prediction of Worldwide Energy Resources) API:

 

Ideally tilt fixed solar panels 33° South in Herrin, United States

To maximize your solar PV system's energy output in Herrin, United States (Lat/Long 37.7992, -89.0227) throughout the year, you should tilt your panels at an angle of 33° South for fixed panel installations.

As the Earth revolves around the Sun each year, the maximum angle of elevation of the Sun varies by +/- 23.45 degrees from its equinox elevation angle for a particular latitude. Finding the exact optimal angle to maximise solar PV production throughout the year can be challenging, but with careful consideration of historical solar energy and meteorological data for a certain location, it can be done precisely.

We use our own calculation, which incorporates NASA solar and meteorological data for the exact Lat/Long coordinates, to determine the ideal tilt angle of a solar panel that will yield maximum annual solar output. We calculate the optimal angle for each day of the year, taking into account its contribution to the yearly total PV potential at that specific location.

Seasonally adjusted solar panel tilt angles for Herrin, United States

If you can adjust the tilt angle of your solar PV panels, please refer to the seasonal tilt angles below for optimal solar energy production in Herrin, United States. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 33° South tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
22° South in Summer	42° South in Autumn	53° South in Winter	31° South in Spring

Our recommendations take into account more than just latitude and Earth's position in its elliptical orbit around the Sun. We also incorporate historical solar and meteorological data from NASA's Prediction of Worldwide Energy Resources (POWER) API to assign a weight to each ideal angle for each day based on its historical contribution to overall solar PV potential during a specific season.

This approach allows us to provide much more accurate recommendations than relying solely on latitude, as it considers unique weather conditions in different locations sharing the same latitude worldwide.

Calculate solar panel row spacing in Herrin, United States

We've added a feature to calculate minimum solar panel row spacing by location. Enter your panel size and orientation below to get the minimum spacing in Herrin, United States.

Our calculation method

1. Solar Position:
   We determine the Sun's position on the Winter solstice using the location's latitude and solar declination.
2. Shadow Projection:
   We calculate the shadow length cast by panels using trigonometry, considering panel tilt and the Sun's elevation angle.
3. Minimum Spacing:
   We add the shadow length to the horizontal space occupied by tilted panels.

This approach ensures maximum space efficiency while avoiding shading during critical times, as the Winter solstice represents the worst-case scenario for shadow length.

Topography for solar PV around Herrin, United States

Topography Around Herrin, Illinois

The landscape surrounding Herrin, Illinois is characterized by gently rolling terrain typical of the southern Illinois region. This area sits within the broader Illinois Basin, where the topography consists of low hills, shallow valleys, and relatively flat agricultural plains. The elevation changes are modest, with most areas ranging between 400 and 600 feet above sea level, creating a landscape that undulates softly rather than presenting dramatic elevation changes. The region features a mix of agricultural fields, scattered woodlands, and small communities connected by rural roads. Much of the land has been shaped by centuries of farming activity, resulting in cleared fields separated by fence rows and occasional stands of deciduous forest. The terrain is well-drained overall, with small creeks and drainage channels cutting shallow valleys through the landscape. Coal mining has historically influenced the local topography, with some areas showing evidence of past surface mining operations that have since been reclaimed. These areas often present flatter, more uniform surfaces than the surrounding natural terrain. The underlying geology consists primarily of sedimentary rocks, including sandstone, shale, and coal seams, which contribute to the generally stable ground conditions.

Optimal Areas for Large-Scale Solar Development

The most suitable locations for large-scale solar photovoltaic installations around Herrin would be the expansive agricultural fields that dominate the regional landscape. These areas offer several advantages, including relatively flat to gently sloping terrain that minimizes grading requirements and construction costs. The open nature of these fields provides excellent solar access with minimal shading from trees or structures. Former agricultural land that has been taken out of production presents particularly attractive opportunities for solar development. These areas often have existing road access and electrical infrastructure nearby, while the land may be available at more favorable terms than actively farmed acreage. The flat to gently rolling character of much of this farmland makes it well-suited for the installation of ground-mounted solar arrays. Reclaimed mining sites in the region also offer potential for solar development. These areas typically have been leveled and stabilized, creating large, relatively flat parcels with good drainage characteristics. The industrial history of such sites often means they already have access to transmission infrastructure, though soil conditions and any remaining environmental considerations would need careful evaluation. Areas to avoid for large-scale solar installations include the steeper hillsides and heavily forested sections, which would require extensive clearing and grading. Low-lying areas prone to flooding or with poor drainage should also be avoided, as should locations with significant existing tree cover that would create shading issues. The ideal sites combine gentle topography, good drainage, existing infrastructure access, and minimal environmental constraints.

United States solar PV Stats as a country

United States ranks 2nd in the world for cumulative solar PV capacity, with 95,209 total MW's of solar PV installed. This means that 3.40% of United States's total energy as a country comes from solar PV (that's 26th in the world). Each year United States is generating 289 Watts from solar PV per capita (United States ranks 15th in the world for solar PV Watts generated per capita). [source]

Are there incentives for businesses to install solar in United States?

Yes, there are several incentives for businesses wanting to install solar energy in the United States. These include federal tax credits, state and local rebates, net metering policies, and renewable energy certificates (RECs). Additionally, many states have enacted legislation that requires utilities to purchase a certain amount of electricity from renewable sources such as solar.

Do you have more up to date information than this on incentives towards solar PV projects in United States? Please reach out to us and help us keep this information current. Thanks!

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Compare this location to others worldwide for solar PV potential

The solar PV analyses available on our website, including this one, are offered as a free service to the global community. Our aim is to provide education and aid informed decision-making regarding solar PV installations.

However, please note that these analyses are general guidance and may not meet specific project requirements. For in-depth, tailored forecasts and analysis crucial for feasibility studies or when pursuing maximum ROI from your solar projects, feel free to contact us; we offer comprehensive consulting services expressly for this purpose.

Helping you assess viability of solar PV for your site

Calculate Your Optimal Solar Panel Tilt Angle: A Comprehensive Guide

Enhance your solar panel's performance with our in-depth guide. Determine the best tilt angle using hard data, debunk common misunderstandings, and gain insight into how your specific location affects solar energy production.