Des Moines, Washington shows significant seasonal variation in solar energy production that makes it a moderately challenging location for year-round solar power generation. Located in the Northern Temperate Zone at coordinates 47.3957, -122.3036, this area experiences the typical Pacific Northwest climate patterns that create distinct periods of high and low solar output.

Seasonal Solar Production Patterns

Summer represents the peak solar generation period at this location, producing 6.89 kWh per day per kW of installed solar capacity. This makes summer nearly three times more productive than the next best season. Spring follows as the second-best performing season with 5.16 kWh per day per kW, offering solid energy production as daylight hours increase and weather patterns improve. Autumn sees a notable decline in solar output, dropping to 2.51 kWh per day per kW of installed capacity. Winter presents the most challenging conditions for solar generation, producing only 1.29 kWh per day per kW - representing less than one-fifth of summer production levels.

Optimal Panel Configuration

For maximum year-round energy production at this Des Moines, Washington location, solar panels should be installed at a fixed tilt angle of 39 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 irradiance data.

Local Factors Affecting Solar Production

Several environmental and weather factors in the Des Moines, Washington area can significantly impact solar energy production:

• Frequent cloud cover and overcast skies, particularly during autumn and winter months
• Marine layer fog from Puget Sound that can reduce morning solar exposure
• Heavy rainfall periods that limit direct sunlight penetration
• Tree coverage and vegetation that may create shading issues
• Salt air from the nearby marine environment that can cause panel corrosion

Preventative Measures for Better Performance

To maximize solar energy production despite these challenges, several installation strategies can be employed:

• Install panels with adequate spacing and proper drainage systems to handle heavy rainfall
• Use marine-grade mounting hardware and regular cleaning schedules to combat salt air corrosion
• Conduct thorough shade analysis and tree trimming to minimize obstructions
• Consider microinverters or power optimizers to reduce impact from partial shading
• Install panels at steeper angles to help rain wash away debris and reduce snow accumulation

Regular maintenance becomes particularly important in this climate, including periodic cleaning to remove moss, lichen, and other organic matter that thrives in the Pacific Northwest's moist conditions. Professional inspections should focus on checking seals and connections that may be compromised by the region's wet weather patterns.

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 DesMoines

Seasonal solar PV output for Latitude: 47.3957, Longitude: -122.3036 (DesMoines, 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 39° South in DesMoines, United States

To maximize your solar PV system's energy output in DesMoines, United States (Lat/Long 47.3957, -122.3036) throughout the year, you should tilt your panels at an angle of 39° 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 DesMoines, 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 DesMoines, United States. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 39° South tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
31° South in Summer	50° South in Autumn	61° South in Winter	39° 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 DesMoines, 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 DesMoines, 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 DesMoines, United States

Topographical Features Around Des Moines, Washington

The area around Des Moines, Washington sits within the Puget Sound region's distinctive glacially-carved landscape. This coastal community is positioned on relatively flat to gently rolling terrain that extends from the shoreline of Puget Sound eastward toward the foothills of the Cascade Range. The immediate vicinity features a series of low bluffs and terraces that were formed by ancient glacial activity, creating a stepped topography that rises gradually from sea level to elevations of several hundred feet.

The landscape is characterized by a mix of marine terraces and gentle slopes, with the most dramatic elevation changes occurring along the bluff faces that drop down to the water. Moving inland from the coast, the terrain becomes more undulating, featuring broad valleys and low ridges that were sculpted by retreating ice sheets thousands of years ago. These formations create a patchwork of relatively flat plateaus separated by shallow depressions and modest hills.

Dense coniferous forests dominate much of the undeveloped land in the region, with Douglas fir, western hemlock, and western red cedar forming the primary canopy. Between the forested areas, the landscape opens into cleared zones that have been converted to residential developments, commercial districts, and some remaining agricultural parcels. The soil composition varies from sandy glacial deposits near the water to heavier clay-based soils further inland.

Optimal Areas for Large-Scale Solar Development

The most promising locations for substantial solar photovoltaic installations would be found on the elevated plateaus and gently sloping hillsides that face south or southwest. These areas offer the dual advantages of relatively level ground for construction and optimal solar exposure throughout the day. The marine terraces, in particular, provide extensive flat areas that would minimize grading requirements and reduce installation costs.

Agricultural zones and former timber lands that have been cleared represent excellent candidates for solar development, as they already lack the tall vegetation that could create shading issues. These areas typically feature open canopies with minimal obstructions, allowing for maximum solar collection efficiency. The cleared agricultural lands south and east of the immediate Des Moines area would be particularly well-suited, as they combine favorable topography with existing infrastructure access.

The elevated ridges and plateaus inland from the coast would also serve as prime locations for solar installations. These areas benefit from their elevation above the marine layer that can sometimes settle over lower-lying coastal areas, potentially providing clearer atmospheric conditions. The gentle slopes found on these elevated areas can actually be advantageous for solar panel positioning, as they can be oriented to optimize sun exposure angles.

Areas to avoid would include the steep bluff faces near the water, heavily forested zones where tree removal would be environmentally problematic, and the low-lying areas that might experience more frequent fog or moisture retention. The immediate shoreline areas, while offering unobstructed southern exposure, may face challenges from salt air corrosion and local zoning restrictions related to waterfront preservation.

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!

Citation Guide

Article Details for Citation

Tell Us About Your Work

We love seeing how our research helps others! If you've cited this article in your work, we'd be delighted to hear about it. Drop us a line via our Contact Us page or on X, to share where you've used our information - we may feature a link to your work on our site. This helps create a network of valuable resources for others in the solar energy community and helps us understand how our research is contributing to the field. Plus, we occasionally highlight exceptional works that reference our research on our social media channels.

Feeling generous?

Share this with your friends!

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.