Castelo Branco, Portugal, situated at latitude 39.8254 and longitude -7.4845, offers a promising location for solar PV energy generation throughout the year. This city in the Northern Temperate Zone experiences varying levels of solar potential across different seasons, making it an interesting case study for solar energy production.

Seasonal Solar Output

The solar energy output in Castelo Branco fluctuates significantly across seasons. Summer stands out as the most productive period, with an impressive 8.24 kWh per day for each kW of installed solar capacity. Spring follows closely, generating 6.15 kWh/day. Autumn sees a moderate decrease to 4.33 kWh/day, while winter experiences the lowest output at 2.47 kWh/day.

Optimal Times for Solar Generation

The most ideal times for solar energy production in Castelo Branco are during the summer months, typically from June to August, when daylight hours are longest and solar irradiance is at its peak. Spring and early autumn also offer favorable conditions for solar generation. While winter months see reduced output, the region still maintains some solar potential even during this period.

Panel Installation and Tilt Angle

For fixed panel installations in Castelo Branco, the optimal tilt angle to maximize year-round solar production is 34 degrees facing South. This angle has been calculated considering various factors, including daily solar elevation angles, Earth's elliptical orbit, and NASA's solar irradiance data for the specific location.

Environmental and Weather Considerations

While Castelo Branco generally offers favorable conditions for solar energy production, there are a few factors that could potentially impact solar output:

1. Dust and pollen: The region's dry climate can lead to dust accumulation on panels, while nearby vegetation may contribute to pollen buildup.
2. Occasional heatwaves: Extremely high temperatures during summer can slightly reduce panel efficiency.

To mitigate these issues, regular panel cleaning should be scheduled, especially during dry periods. Installing panels with good heat dissipation properties and ensuring proper ventilation can help maintain efficiency during heatwaves. Overall, these factors are not significant impediments to solar production in Castelo Branco, and with proper maintenance, the location remains highly suitable for solar PV energy generation.

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 Castelo Branco

Seasonal solar PV output for Latitude: 39.8254, Longitude: -7.4845 (Castelo Branco, 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:

Average 8.24kWh/day in Summer.

Average 4.33kWh/day in Autumn.

Average 2.47kWh/day in Winter.

Average 6.15kWh/day in Spring.

Ideally tilt fixed solar panels 34° South in Castelo Branco, Portugal

To maximize your solar PV system's energy output in Castelo Branco, Portugal (Lat/Long 39.8254, -7.4845) 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.

At Latitude: 39.8254, Longitude: -7.4845, the ideal angle to tilt panels is 34° South

Seasonally adjusted solar panel tilt angles for Castelo Branco, 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 Castelo Branco, Portugal. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 34° South tilt angle throughout the year.

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 Castelo Branco, 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 Castelo Branco, 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 Castelo Branco, Portugal

The area around Castelo Branco, Portugal, is characterized by a diverse and interesting topography. This region, located in the central-eastern part of the country, is part of the Beira Baixa province and sits at the foothills of the Serra da Estrela mountain range.

The landscape surrounding Castelo Branco is generally hilly, with gentle to moderate slopes dominating much of the terrain. The city itself is situated on a small hill, providing panoramic views of the surrounding countryside. To the north and east, the land gradually rises towards the more mountainous areas of the Serra da Gardunha and Serra do Muradal.

The southern and western parts of the region feature a mix of rolling hills and flat plains, with occasional rocky outcrops. These areas are typically covered in a patchwork of agricultural fields, olive groves, and cork oak forests. The Ponsul River and its tributaries cut through the landscape, creating small valleys and adding to the topographical variety.

For large-scale solar PV installations, the areas most suited would be the flatter regions to the south and southwest of Castelo Branco. These areas offer several advantages for solar energy production:

1. They have relatively level terrain, which simplifies construction and reduces costs associated with land preparation.
2. The open nature of these areas means there are fewer obstructions that could cast shadows on solar panels.
3. The region receives ample sunlight throughout the year, making it ideal for solar energy generation.
4. These areas are generally less densely populated, which could minimize potential conflicts with residential or agricultural land use.

Specifically, the plains extending towards the towns of Idanha-a-Nova and Proença-a-Nova would be prime candidates for large-scale solar PV projects. These areas combine favorable topography with good solar exposure and relatively easy access to existing infrastructure.

It's worth noting that while the hilly areas to the north and east may not be as suitable for large-scale installations, they could still be appropriate for smaller, distributed solar projects. The varied topography of these regions could potentially be leveraged for innovative solar designs that take advantage of natural slopes and orientations.

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!

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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

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