Solar PV Analysis of Viana Do Castelo, Portugal
Viana do Castelo, Portugal, situated at latitude 41.6929 and longitude -8.8391, presents a mixed picture for solar PV energy generation throughout the year. This coastal city in northern Portugal experiences significant seasonal variations in solar energy production, which can impact the overall efficiency of solar installations.
Seasonal Solar Performance
The location's solar energy potential fluctuates considerably across the four seasons. Summer stands out as the most productive period, with an impressive daily output of 7.43 kWh per kW of installed solar capacity. Spring follows closely behind, generating 6.09 kWh per day. However, the colder months see a substantial drop in energy production, with autumn yielding 3.97 kWh daily and winter experiencing the lowest output at just 2.19 kWh per day.
This seasonal disparity indicates that Viana do Castelo is most suitable for solar energy generation during the warmer months, particularly from late spring through early autumn. During this period, longer daylight hours and more direct sunlight contribute to higher energy yields.
Optimal Panel Positioning
To maximize year-round solar energy production in Viana do Castelo, fixed solar panels should be installed at a tilt angle of 36 degrees facing south. This orientation helps optimize the panels' exposure to sunlight throughout the year, balancing the varying sun angles across seasons.
Environmental and Weather Considerations
While Viana do Castelo's location is generally favorable for solar energy production, there are some environmental factors to consider:
- Coastal fog: Being a coastal city, morning fog can occasionally reduce solar efficiency, especially in late autumn and winter.
- Atlantic storms: The region may experience storms that can temporarily decrease solar output and potentially damage installations if not properly secured.
To mitigate these challenges, solar installations should incorporate robust mounting systems to withstand strong winds. Additionally, regular cleaning of panels to remove salt spray deposits can help maintain optimal performance. Implementing a monitoring system can also aid in quickly identifying and addressing any weather-related impacts on energy production.
In conclusion, while Viana do Castelo's location is not ideal year-round for solar PV energy generation, it offers significant potential during the warmer months. With proper installation techniques and maintenance practices, solar energy can be a viable and sustainable power source for this Portuguese coastal city.
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 179 locations across Portugal. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in Portugal by location
Solar output per kW of installed solar PV by season in Viana Do Castelo
Seasonal solar PV output for Latitude: 41.6929, Longitude: -8.8391 (Viana Do Castelo, Portugal), 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 36° South in Viana Do Castelo, Portugal
To maximize your solar PV system's energy output in Viana Do Castelo, Portugal (Lat/Long 41.6929, -8.8391) throughout the year, you should tilt your panels at an angle of 36° 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 Viana Do Castelo, Portugal
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 Viana Do Castelo, Portugal. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 36° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 26° South in Summer | 46° South in Autumn | 57° South in Winter | 34° 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 Viana Do Castelo, Portugal
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 Viana Do Castelo, Portugal.
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 Viana Do Castelo, Portugal
The topography around Viana do Castelo, Portugal, is quite diverse and picturesque. This coastal city is situated where the Lima River meets the Atlantic Ocean, creating a unique landscape that combines maritime, riverine, and mountainous features.
To the north and east of Viana do Castelo, the terrain becomes increasingly hilly and mountainous. The Serra d'Arga mountain range dominates the northeastern landscape, with its highest peak reaching about 800 meters above sea level. These mountains are characterized by rugged slopes, rocky outcrops, and areas of dense vegetation.
To the south and southeast, the land is generally flatter, with gentle hills and valleys. This area is part of the Lima Valley, which stretches inland along the Lima River. The valley floor is relatively wide and flat, with fertile soil that supports agricultural activities.
The immediate coastal area around Viana do Castelo features long stretches of sandy beaches interspersed with rocky cliffs and small coves. The coastline is relatively straight but punctuated by the Lima River estuary and several smaller streams that flow into the Atlantic Ocean.
For large-scale solar PV installations, the areas most suited would likely be the flatter regions to the south and southeast of Viana do Castelo. These areas in the Lima Valley offer several advantages for solar energy production:
- The relatively flat terrain makes construction and maintenance easier.
- There is less shadowing from mountains or tall vegetation.
- The open spaces allow for larger installations without significant land use conflicts.
- The proximity to existing infrastructure in the valley could facilitate grid connections.
However, it's important to note that specific site selection would require detailed environmental and technical assessments. Factors such as local climate conditions, grid capacity, and land use regulations would need to be carefully considered. Additionally, while the mountainous areas to the north might seem less suitable for large-scale installations, they could potentially host smaller, distributed solar projects on south-facing slopes.
Portugal solar PV Stats as a country
Portugal ranks 32nd in the world for cumulative solar PV capacity, with 1,801 total MW's of solar PV installed. This means that 3.40% of Portugal's total energy as a country comes from solar PV (that's 23rd in the world). Each year Portugal is generating 174 Watts from solar PV per capita (Portugal ranks 29th in the world for solar PV Watts generated per capita). [source]
Are there incentives for businesses to install solar in Portugal?
Yes, there are several incentives for businesses wanting to install solar energy in Portugal. The Portuguese government offers a range of financial incentives and tax breaks for businesses that invest in renewable energy sources such as solar power. These include grants, loans, and tax credits. Additionally, the government has set up a feed-in tariff system which guarantees a fixed price for electricity generated from renewable sources such as solar power. This helps to make investing in solar energy more attractive to businesses.
Do you have more up to date information than this on incentives towards solar PV projects in Portugal? 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: Wednesday 17th of July 2024
Last Updated: Monday 21st of July 2025
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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.
