Erwin, Tennessee is a moderately good location for year-round solar energy generation, though it experiences significant seasonal variation typical of its Northern Temperate Zone climate. The area produces its highest solar output during summer months at 6.55 kWh per day per kW of installed capacity, followed by a strong spring season at 5.64 kWh per day per kW.

Seasonal Performance Patterns

Solar production drops considerably during autumn and winter months, with autumn generating 4.18 kWh per day per kW and winter producing only 2.38 kWh per day per kW. This winter low represents less than half the summer peak output, making it the least productive season for solar energy generation in Erwin. For optimal year-round performance, solar panels should be installed at a fixed tilt angle of 31 degrees facing south. This angle maximizes total annual energy production by accounting for the sun's changing position throughout the year and the varying solar irradiance levels at this latitude.

Local Factors Affecting Solar Production

Several environmental and weather factors in the Erwin, Tennessee area can impact solar panel performance:

• Heavy snow accumulation during winter months can block panels and significantly reduce output
• Frequent cloud cover and overcast conditions, particularly common in this region's climate
• High humidity levels that can create haze and reduce solar irradiance
• Potential for severe weather including thunderstorms and occasional ice storms
• Dust and pollen buildup, especially during spring months when the area experiences high pollen counts

Preventative Installation Measures

To maximize energy production despite these challenges, several installation strategies can help:

• Install panels with adequate tilt (the recommended 31 degrees) to promote natural snow and debris shedding
• Ensure easy access for cleaning and maintenance to remove accumulated dirt, pollen, and debris
• Use high-quality mounting systems designed to withstand severe weather and ice loading
• Consider micro-inverters or power optimizers to minimize impact when individual panels are partially shaded or dirty
• Plan for regular cleaning schedules, particularly after high pollen seasons and before peak production months

Despite these challenges, Erwin's location still offers reasonable solar potential, particularly during the productive spring and summer seasons when energy demand for cooling is typically highest.

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 Erwin

Seasonal solar PV output for Latitude: 36.1411, Longitude: -82.4313 (Erwin, 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 31° South in Erwin, United States

To maximize your solar PV system's energy output in Erwin, United States (Lat/Long 36.1411, -82.4313) throughout the year, you should tilt your panels at an angle of 31° 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 Erwin, 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 Erwin, United States. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 31° South tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
20° South in Summer	41° South in Autumn	51° South in Winter	29° 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 Erwin, 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 Erwin, 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 Erwin, United States

Topographical Features Around Erwin

Erwin, Tennessee sits nestled in the scenic Appalachian Mountains of East Tennessee, positioned within Unicoi County at an elevation of approximately 1,650 feet above sea level. The town is strategically located in the Nolichucky River valley, surrounded by the rolling hills and ridges characteristic of the southern Appalachian region. The landscape features a mix of moderately steep terrain, with numerous ridgelines running in a northeast-southwest orientation, typical of the Appalachian Mountain system.

The immediate area around Erwin displays varied topography, with the town center occupying relatively flat valley floor terrain along the Nolichucky River. Moving outward from the river valley, the land gradually rises into forested hills and ridges that create the distinctive "hollows" and "gaps" common throughout Appalachian Tennessee. These ridges typically range from 2,000 to 3,500 feet in elevation, creating a moderately mountainous environment with significant variation in slope and aspect across short distances.

The region's geology consists primarily of sedimentary rocks, including sandstone, shale, and limestone formations that have been folded and weathered over millions of years. This geological foundation contributes to the area's characteristic ridge-and-valley topography, with numerous small streams and creeks flowing through the valleys to eventually join the Nolichucky River system.

Optimal Areas for Large-Scale Solar Development

For large-scale solar photovoltaic installations in the Erwin vicinity, the most suitable locations would be the relatively flat to gently sloping areas found in the broader river valleys and on selected ridge tops. The Nolichucky River valley itself offers some of the most promising terrain, particularly on the agricultural lands and open fields that extend along the river corridor. These areas provide the necessary flat or south-facing gentle slopes ideal for solar panel installation while offering easier access for construction and maintenance vehicles.

Ridge top locations present another viable option for solar development, particularly those ridges with southern exposure and minimal tree cover. Many of the higher elevation ridges in the area have been cleared for agriculture or development, creating open spaces that could accommodate solar arrays. The elevated positions of these ridge top sites can provide advantages in terms of reduced shading from surrounding vegetation and structures.

The agricultural valleys extending northeast and southwest of Erwin along the regional transportation corridors represent perhaps the most practical locations for utility-scale solar installations. These areas typically feature gentler topography, existing road access, and proximity to electrical transmission infrastructure. The relatively open character of these agricultural valleys, combined with their favorable orientation and reduced tree coverage, makes them well-suited for large solar developments.

Areas to avoid for large-scale solar development include the steeper north-facing slopes, heavily forested hillsides, and narrow hollows where shading from surrounding ridges would significantly impact solar collection efficiency. The numerous small valleys and drainage areas throughout the region, while scenic, generally lack the consistent solar exposure and accessible terrain necessary for commercial-scale solar installations.

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.