Rio Maior, Portugal, situated at 39.3323° N, 8.9389° W, offers a promising location for solar PV energy generation throughout the year. This Northern Temperate Zone site experiences distinct seasonal variations in solar energy production, which are worth examining in detail.

Seasonal Solar Production

The solar energy output at Rio Maior fluctuates significantly across the four seasons. Summer stands out as the most productive period, with an impressive 7.87 kWh per day for each kW of installed solar capacity. Spring follows as the second-most productive season, generating 6.02 kWh daily. Autumn sees a notable decrease to 4.28 kWh per day, while winter experiences the lowest output at 2.43 kWh daily. These figures highlight the substantial difference between summer and winter production, with summer generating more than three times the energy of winter days. This variation is primarily due to the changing angle of the sun and daylight hours throughout the year.

Optimal Times for Solar Generation

The most ideal period for solar energy production in Rio Maior spans from late spring through early autumn. During these months, longer days and higher sun angles contribute to increased solar panel efficiency. The summer solstice, occurring around June 21st, marks the peak of solar potential, with the longest day of the year providing maximum sunlight exposure.

Panel Tilt Optimization

To maximize year-round solar energy production in Rio Maior, fixed solar panels should be installed at a tilt angle of 34 degrees facing south. This optimal angle has been calculated considering the site's latitude, seasonal sun positions, and daily PV potential, ensuring the best possible energy capture throughout the year.

Environmental and Weather Considerations

While Rio Maior generally offers favorable conditions for solar energy production, there are a few factors to consider: 1. Occasional Atlantic storms: These can bring periods of heavy cloud cover and rainfall, temporarily reducing solar output. 2. Dust and pollen: The region's agricultural activities may lead to airborne particles that can accumulate on panels, slightly decreasing efficiency. To mitigate these issues, consider implementing the following measures:

• Install a robust mounting system capable of withstanding strong winds
• Use self-cleaning panels or schedule regular cleaning to combat dust and pollen accumulation
• Implement a monitoring system to track performance and quickly identify any issues

By addressing these factors, solar installations in Rio Maior can maintain high efficiency and capitalize on the location's overall favorable conditions for solar energy production.

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 Rio Maior, Santarém

Seasonal solar PV output for Latitude: 39.3323, Longitude: -8.9389 (Rio Maior, Santarém, 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 34° South in Rio Maior, Santarém, Portugal

To maximize your solar PV system's energy output in Rio Maior, Santarém, Portugal (Lat/Long 39.3323, -8.9389) throughout the year, you should tilt your panels at an angle of 34° 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 Rio Maior, Santarém, 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 Rio Maior, Santarém, Portugal. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 34° South tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
23° South in Summer	44° South in Autumn	54° South in Winter	32° 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 Rio Maior, Santarém, 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 Rio Maior, Santarém, Portugal.

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 Rio Maior, Santarém, Portugal

The area around Rio Maior, Portugal, is characterized by a diverse and interesting topography. Located in the western part of the country, this region features a mix of rolling hills, gentle valleys, and some flatter areas. The landscape is typical of central Portugal's interior, with elevations gradually increasing as you move eastward from the coast.

Rio Maior itself sits in a small valley surrounded by low hills. To the west, the terrain becomes more level as it approaches the Atlantic coast, about 40 kilometers away. To the east and northeast, the hills become more pronounced, eventually leading to the Serra dos Candeeiros mountain range. This range, part of the larger Serras de Aire e Candeeiros Natural Park, features limestone formations and reaches heights of around 600 meters above sea level.

The region's climate is Mediterranean, with warm, dry summers and mild, wet winters. This climate, combined with the varied topography, has shaped a landscape that includes areas of forest, agricultural land, and some more rugged, less vegetated zones.

Areas Suitable for Large-Scale Solar PV

When considering locations for large-scale solar photovoltaic (PV) installations near Rio Maior, several factors come into play. The most suitable areas would generally be:

1. The flatter regions to the west and southwest of Rio Maior would be prime candidates for solar PV installations. These areas offer more level ground, which is ideal for large arrays of solar panels. The relatively low-lying terrain also means less shadowing from hills or mountains, allowing for maximum sun exposure throughout the day.

2. Some of the gentler hill slopes to the south and southeast of Rio Maior could also be suitable. While not as ideal as completely flat land, south-facing slopes can actually be advantageous for solar panels, as they naturally angle towards the sun's path.

3. Agricultural areas that are less productive or fallow might be considered for solar PV use. The region has a mix of farmland, and some of these spaces could potentially be dual-purposed for both agriculture and solar energy production, a practice known as agrivoltaics.

It's important to note that while the topography is suitable in many areas, other factors such as grid connection availability, local regulations, and environmental considerations would also play crucial roles in determining the best locations for large-scale solar PV installations. Any development would need to balance energy production goals with preservation of the region's natural beauty and ecological importance.

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

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.