Harrisburg, Illinois represents a moderately favorable location for year-round solar energy generation, though with significant seasonal variation typical of the Northern Temperate Zone. The area experiences its peak solar production during summer months at 6.60 kWh per day per kW of installed capacity, while winter production drops substantially to just 2.38 kWh per day per kW.

Seasonal Solar Performance

The location shows strong seasonal patterns in solar energy output. Spring offers excellent production at 5.58 kWh per day per kW, making it nearly as productive as summer. Autumn provides moderate generation at 4.07 kWh per day per kW, while winter represents the most challenging period with the lowest output.

For optimal year-round performance at this location, solar panels should be installed at a fixed tilt angle of 33 degrees facing south. This angle maximizes total annual energy production by accounting for the sun's varying position throughout the year and the location's specific latitude.

Environmental and Weather Challenges

Several factors in the Harrisburg area can impede solar energy production. The region experiences frequent cloud cover and precipitation, particularly during winter and spring months, which can significantly reduce solar irradiance reaching the panels.

Illinois weather patterns include:

• Heavy snow accumulation during winter months that can block panels
• Severe thunderstorms with hail potential during spring and summer
• High humidity levels that can reduce panel efficiency
• Occasional ice storms that can damage equipment

Preventative Installation Measures

To maximize energy production despite these challenges, several installation strategies prove beneficial. Panels should be mounted with adequate spacing to allow snow to slide off naturally, and the 33-degree tilt angle helps facilitate this process.

Installing panels with anti-reflective coatings and ensuring proper ventilation behind panels helps combat humidity-related efficiency losses. Using tempered glass and robust mounting systems protects against hail damage, while surge protection devices safeguard against lightning strikes common during thunderstorms.

Regular maintenance including cleaning and snow removal when necessary ensures optimal performance year-round. Despite these challenges, Harrisburg's location still provides reasonable solar potential, particularly during the longer, sunnier months from spring through early autumn.

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 Harrisburg, Illinois

Seasonal solar PV output for Latitude: 37.7285, Longitude: -88.552 (Harrisburg, Illinois, 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 Harrisburg, Illinois, United States

To maximize your solar PV system's energy output in Harrisburg, Illinois, United States (Lat/Long 37.7285, -88.552) 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 Harrisburg, Illinois, 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 Harrisburg, Illinois, 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	30° 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 Harrisburg, Illinois, 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 Harrisburg, Illinois, 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 Harrisburg, Illinois, United States

Topographical Features of the Harrisburg Region

The area surrounding Harrisburg in southeastern Illinois is characterized by gently rolling terrain that forms part of the Interior Plains physiographic region. This landscape represents a transition zone between the flatter agricultural lands to the north and the more rugged terrain of the Shawnee Hills to the south. The elevation in the immediate vicinity ranges from approximately 350 to 450 feet above sea level, with subtle undulations creating a moderately varied topography. The region sits within the broader context of the Illinois Basin, where ancient geological processes have created a relatively stable foundation with gradual slopes and well-drained uplands. Small creeks and tributaries have carved shallow valleys throughout the area, creating a network of gentle ridges and lowlands. The underlying bedrock consists primarily of sedimentary formations, with surface soils developed from glacial deposits and weathered rock materials.

Drainage Patterns and Land Use

The drainage system in this part of Illinois flows generally southward toward the Ohio River, with numerous small streams creating a dendritic pattern across the landscape. These waterways have established floodplains of varying widths, though most are relatively narrow given the modest size of the streams. The interfluves between these drainage corridors provide elevated, well-drained sites that are less susceptible to flooding and seasonal water table fluctuations. Agricultural activities dominate much of the surrounding countryside, with a mix of crop production and pastureland utilizing the fertile soils. Scattered woodlands occupy steeper slopes and areas less suitable for cultivation, while small towns and rural residences are distributed throughout the region following historical settlement patterns along transportation corridors.

Optimal Areas for Large-Scale Solar Development

The most promising locations for extensive solar photovoltaic installations would be found on the elevated plateaus and broad ridgetops that characterize the upland areas. These sites offer several advantages including relatively level terrain that minimizes grading requirements, excellent drainage characteristics that reduce infrastructure maintenance concerns, and sufficient elevation to avoid potential flooding issues during extreme weather events. The agricultural lands occupying these elevated positions would be particularly well-suited for solar development, as they typically feature gentle slopes of less than five percent and have been cleared of significant vegetation. The existing field patterns often provide large, contiguous areas that could accommodate substantial solar arrays without the complications of fragmented ownership or irregular boundaries. Areas to the north and east of Harrisburg appear especially favorable, where the terrain becomes more uniform and the elevation changes are minimal across extensive tracts of farmland. These locations would allow for efficient installation of tracking systems and optimal panel orientation while maintaining reasonable access for construction and maintenance activities.

Considerations for Site Selection

While much of the surrounding region offers suitable topographical conditions, certain areas would be less appropriate for large-scale solar development. The narrow floodplains of local streams should be avoided due to periodic inundation and higher soil moisture levels. Similarly, the steeper slopes found along creek valleys and in areas where the terrain transitions toward the Shawnee Hills would present challenges for installation and potentially compromise system efficiency. The scattered woodland areas, while often occupying well-drained sites, would require significant clearing and might face environmental restrictions. However, previously cleared upland sites that have reverted to early successional vegetation could represent good opportunities if they retain favorable topographical characteristics and appropriate access to transmission infrastructure.

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.