Solar PV Analysis of Spanaway, United States
Spanaway, Washington, located in the Northern Temperate Zone, presents a mixed picture for solar energy generation. This location experiences significant seasonal variations in solar output, which impacts the overall efficiency of solar PV systems throughout the year.
Seasonal Solar Performance
Solar energy production in Spanaway varies dramatically across seasons. Summer stands out as the most productive period, with an impressive 6.91 kWh per day for each kW of installed solar capacity. Spring follows as the second-best season, generating 5.21 kWh daily. However, autumn and winter see a substantial drop in output, with 2.54 kWh and 1.33 kWh per day, respectively.
Optimal Times for Solar Generation
The ideal time for solar energy production in Spanaway is clearly during the summer months, typically from June through August. Spring, particularly from April to May, also offers favorable conditions. These periods benefit from longer daylight hours and generally clearer skies, maximizing solar panel efficiency.
Panel Tilt Optimization
For fixed panel installations in Spanaway, the optimal tilt angle to maximize year-round solar production is 39 degrees facing South. This angle is calculated to balance the varying solar elevations throughout the year, ensuring the best possible energy capture across all seasons.
Environmental and Weather Considerations
Spanaway's location presents some challenges for solar energy production:
- Cloud cover: The Pacific Northwest is known for its frequent overcast conditions, especially during fall and winter. This can significantly reduce solar output.
- Rain: The area experiences considerable rainfall, which can affect panel efficiency and require more frequent cleaning.
- Short winter days: Being in the Northern Temperate Zone, Spanaway has notably shorter days during winter, limiting solar exposure.
Preventative Measures
To mitigate these challenges and enhance solar production, consider the following:
- Use high-efficiency panels designed to perform well in low-light conditions.
- Install a solar tracking system to maximize exposure throughout the day.
- Implement regular cleaning and maintenance to combat the effects of rain and potential debris.
- Consider supplementary energy sources for the less productive winter months.
While Spanaway may not be ideal for year-round solar production, with proper planning and equipment selection, it can still be a viable location for solar energy systems, particularly during the spring and summer months.
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 Spanaway
Seasonal solar PV output for Latitude: 47.104, Longitude: -122.4346 (Spanaway, 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 Spanaway, United States
To maximize your solar PV system's energy output in Spanaway, United States (Lat/Long 47.104, -122.4346) 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 Spanaway, 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 Spanaway, 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 | 49° 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 Spanaway, 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 Spanaway, United States.
Our calculation method
- Solar Position:
We determine the Sun's position on the Winter solstice using the location's latitude and solar declination. - Shadow Projection:
We calculate the shadow length cast by panels using trigonometry, considering panel tilt and the Sun's elevation angle. - 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 Spanaway, United States
The topography around Spanaway, Washington, in the United States is characterized by a mix of gently rolling terrain and relatively flat areas. Spanaway is located in the western part of Pierce County, nestled in the Puget Sound lowlands. This region is part of a larger geological feature known as the Puget Sound Basin, which was shaped by glacial activity during the last ice age.
The landscape surrounding Spanaway is primarily composed of glacial till and outwash plains, resulting in a generally level to moderately undulating surface. The area's elevation is relatively low, averaging around 300 to 400 feet above sea level. To the east of Spanaway, the terrain gradually rises towards the foothills of the Cascade Mountain range, while to the west, it remains fairly flat as it approaches the Puget Sound.
Several small lakes and ponds dot the landscape near Spanaway, including Spanaway Lake itself, which lies just to the southeast of the community. The area also features numerous small streams and creeks that contribute to the local watershed.
When considering areas nearby that would be most suited for large-scale solar PV (photovoltaic) installations, there are a few factors to consider. The ideal locations would have the following characteristics:
- Relatively flat or gently sloping terrain to minimize installation costs and maximize sun exposure
- Open areas with minimal shading from trees or buildings
- Proximity to existing electrical infrastructure for easier grid connection
- Land that is not prime agricultural or ecologically sensitive
Given these criteria, some of the most suitable areas for large-scale solar PV near Spanaway might include:
1. The plains to the south and southeast of Spanaway, extending towards Graham and Frederickson. These areas have more open, agricultural land that could potentially be repurposed for solar installations.
2. The relatively flat areas to the west and southwest of Spanaway, towards Lakewood and Joint Base Lewis-McChord. While some of this land is occupied by the military base, there may be suitable locations on private property or unused portions of the base.
3. The gently rolling terrain to the east of Spanaway, moving towards the community of Elk Plain. This area has a mix of open spaces and lightly forested regions that could accommodate solar farms.
It's important to note that while these areas may be topographically suitable, any large-scale solar PV project would require extensive environmental impact studies, local zoning approvals, and consideration of the region's climate, including its frequent cloud cover and rainfall patterns, which could affect the overall efficiency of solar power generation in the area.
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
Author: Aaron Robinson
Publisher: profileSOLAR.com
First Published: Friday 18th of October 2024
Last Updated: Monday 21st of July 2025
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.
