Ketchikan, Alaska, in the United States is a challenging location for solar PV energy generation throughout the year. Situated in the Northern Temperate Zone at coordinates 55.3404, -131.6519, this location experiences significant seasonal variations in solar energy production.

The solar energy output at this location follows a predictable seasonal pattern. During summer, panels can produce a respectable 4.72 kWh per day for each kilowatt of installed capacity. Spring is the second most productive season, generating 3.69 kWh/day per kW installed. However, production drops dramatically during autumn to just 1.27 kWh/day, and winter sees the lowest output at a mere 0.76 kWh/day per kW installed.

For fixed panel installations in Ketchikan, the ideal tilt angle to maximize year-round production is 46 degrees facing South. This angle has been carefully calculated to optimize annual energy capture considering the location's specific latitude and seasonal solar patterns.

Environmental and Weather Challenges

Several significant environmental factors impede solar production in Ketchikan. The region is known for its extremely high annual rainfall—one of the wettest locations in the United States—which creates frequent cloud cover that reduces solar exposure. Additionally, Ketchikan experiences heavy snowfall in winter months, which can cover panels and further reduce the already minimal winter production.

The location's northern latitude means shorter daylight hours in winter, compounding the seasonal production differences. Ketchikan is also surrounded by mountains and dense forests that can create shading issues depending on the specific installation site.

Preventative Measures for Better Production

To maximize solar energy production in this challenging environment, several preventative measures can be implemented:

• Install panels with snow-shedding capabilities and consider adding a snow removal system for winter months
• Use high-efficiency panels specifically designed for low-light conditions
• Implement micro-inverters or power optimizers to minimize the impact of partial shading
• Consider adjustable mounting systems to optimize tilt seasonally rather than using a fixed 46-degree angle
• Incorporate robust waterproofing and moisture protection for all system components
• Conduct thorough site assessment to identify and avoid potential shading from surrounding trees and mountains

Given the significant seasonal variation, Ketchikan solar installations would benefit from being part of a hybrid energy system rather than relied upon as a primary energy source. The substantial difference between summer and winter production suggests that energy storage solutions would be particularly valuable to help balance the seasonal disparities.

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 Ketchikan

Seasonal solar PV output for Latitude: 55.3404, Longitude: -131.6519 (Ketchikan, 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 46° South in Ketchikan, United States

To maximize your solar PV system's energy output in Ketchikan, United States (Lat/Long 55.3404, -131.6519) throughout the year, you should tilt your panels at an angle of 46° 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 Ketchikan, 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 Ketchikan, United States. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 46° South tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
39° South in Summer	58° South in Autumn	69° South in Winter	47° 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 Ketchikan, 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 Ketchikan, 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 Ketchikan, United States

Ketchikan, nestled along the southeastern coast of Alaska, boasts a dramatic and rugged topography characteristic of the Pacific Northwest's coastal regions. The landscape is dominated by steep, forested mountains that rise abruptly from the sea, creating a striking visual contrast between the deep blue waters of the Tongass Narrows and the verdant slopes that surround the city. The terrain around Ketchikan is part of the massive Tongass National Forest, the largest national forest in the United States. The mountains in this region typically range from 2,000 to 3,500 feet in elevation, with some peaks reaching higher. These mountains are densely covered with a temperate rainforest ecosystem, primarily consisting of Sitka spruce, western hemlock, western red cedar, and Alaska yellow cedar.

Coastal Features and Waterways

The coastline near Ketchikan is highly irregular, characterized by numerous islands, fjords, and inlets. Revillagigedo Island, on which Ketchikan is situated, is separated from the mainland by the Tongass Narrows, a relatively narrow channel that serves as a major shipping route. The surrounding waters include the Clarence Strait to the west and Behm Canal to the east, both part of the larger Inside Passage. Numerous streams and rivers cut through the mountainous terrain, creating valleys and watersheds that drain into the surrounding marine waters. These waterways have historically shaped both the natural environment and human settlement patterns in the region.

Challenges for Solar PV Development

The topographical characteristics of Ketchikan present significant challenges for large-scale solar photovoltaic (PV) development. The steep, mountainous terrain limits the availability of large, flat areas that would be ideal for solar installations. Additionally, the dense forest cover would require substantial clearing, raising both environmental concerns and increasing development costs. The region's orientation within narrow valleys surrounded by high mountains creates significant shading issues throughout much of the day, particularly during winter months when the sun's path is lower in the sky. This natural shading effect reduces the potential solar exposure for many areas.

Potential Areas for Solar Development

Despite these challenges, certain areas near Ketchikan might offer better conditions for solar PV installations: Cleared ridgelines and south-facing slopes would receive more direct sunlight than valley bottoms. Some of the higher elevation areas, particularly those with southern exposure and minimal tree cover, could potentially accommodate smaller-scale solar installations. The Ketchikan International Airport area, located on Gravina Island across from the main town, contains some relatively flat, cleared land that might be suitable for solar development, though space is limited. Existing industrial areas, particularly those associated with the region's timber industry or old mining operations, may offer previously disturbed landscapes that could be repurposed for solar installations without additional forest clearing.

Regional Context

When considering potential solar development sites, it's worth noting that areas further inland and to the east of Ketchikan, beyond the immediate coastal mountains, feature somewhat less precipitous terrain. The transition zone between the coastal mountains and the interior regions contains some broader valleys and more gradual slopes that might offer better topographical conditions for solar installations. However, the fundamental constraints of the region's northern latitude, mountainous character, and forest cover mean that large-scale solar development would face significant natural barriers compared to more favorable locations elsewhere in the United States. Any substantial solar projects would likely need to be carefully sited and designed to work within these topographical limitations.

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.