Tomar, Santarém, Portugal offers reasonably good conditions for year-round solar energy generation, though with significant seasonal variations typical of its Northern Temperate Zone location.

Seasonal Solar Performance

The solar energy output at Tomar varies considerably throughout the year. Summer provides the strongest performance at 7.85 kWh per day per kW of installed solar capacity, making it an excellent time for solar generation. Spring also delivers solid results with 5.99 kWh per day per kW, representing the second-best season for solar production. Autumn sees a notable drop to 4.22 kWh per day per kW, while winter presents the most challenging conditions with only 2.39 kWh per day per kW. This winter figure represents roughly 30% of summer production, highlighting the significant seasonal variation that solar system owners should expect.

Optimal Panel Configuration

For maximum year-round energy production at Tomar, Santarém, solar panels should be installed at a fixed tilt angle of 34 degrees facing South. This angle has been calculated to optimize total annual output by accounting for the sun's changing position throughout the year and weighting for the varying solar irradiance levels across different seasons.

Local Factors Affecting Solar Production

Several environmental and weather factors in the Tomar region can impact solar energy generation:

• Atlantic weather patterns bringing cloud cover and precipitation, particularly during autumn and winter months
• Morning fog and mist common in central Portugal's river valleys
• Dust accumulation from agricultural activities in the surrounding countryside
• Occasional wildfire smoke during dry summer periods

Preventative Measures for Optimal Performance

To maximize solar energy production despite these challenges, several installation strategies can be employed. Regular panel cleaning schedules should be established, particularly during dusty agricultural seasons and after any nearby wildfire activity. Installing panels with adequate spacing allows for proper air circulation and easier maintenance access. Choosing high-quality panels with anti-reflective coatings can help maintain efficiency even during periods of reduced sunlight. Micro-inverters or power optimizers can minimize the impact when individual panels are partially shaded or dirty, ensuring that problems with one panel don't significantly affect the entire system's performance. Proper drainage around panel installations prevents water pooling that could lead to increased humidity and potential equipment issues. Additionally, monitoring systems can alert owners to performance drops that might indicate cleaning or maintenance needs.

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 Tomar

Seasonal solar PV output for Latitude: 39.6018, Longitude: -8.4104 (Tomar, 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 Tomar, Portugal

To maximize your solar PV system's energy output in Tomar, Portugal (Lat/Long 39.6018, -8.4104) 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 Tomar, 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 Tomar, 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
24° South in Summer	44° South in Autumn	55° 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 Tomar, 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 Tomar, 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 Tomar, Portugal

Topography Around Tomar

Tomar sits in the heart of central Portugal within the Médio Tejo region, positioned along the banks of the Nabão River. The landscape surrounding this historic city is characterized by gently rolling hills and river valleys that create a varied but generally moderate terrain. The elevation around Tomar typically ranges from approximately 60 meters at the river level to around 200-300 meters on the surrounding hilltops, making it part of Portugal's central plateau region.

The area features a mix of agricultural plains, forested hills, and scattered urban development. To the east and southeast, the terrain gradually rises toward the foothills of the Serra da Lousã mountain range, while westward the landscape opens into broader valleys and plains that extend toward the Atlantic coastal regions. The Nabão River and its tributaries have carved gentle valleys through the landscape, creating natural corridors of flatter terrain interspersed with low ridges and hills.

The geology consists primarily of sedimentary rocks and alluvial deposits, with limestone formations common throughout the region. This has resulted in relatively stable ground conditions and well-drained soils across much of the area. The climate influence of the nearby Atlantic Ocean, combined with the inland continental effects, creates a Mediterranean climate with distinct wet and dry seasons.

Optimal Areas for Large-Scale Solar Development

The most suitable locations for large-scale solar photovoltaic installations around Tomar would be the gently sloping hillsides and plateau areas that extend to the south and southeast of the city. These elevated areas, typically between 150-250 meters in elevation, offer excellent southern exposure while maintaining relatively gentle gradients that minimize construction challenges and maximize panel efficiency through optimal positioning.

The agricultural plains to the southwest and west of Tomar present another excellent opportunity for solar development. These flatter areas require minimal grading and earthwork, reducing installation costs while providing ample space for large arrays. The relatively open landscape in these directions also minimizes shading concerns from topographic features or existing vegetation.

The plateau areas extending toward the municipalities of Ferreira do Zêzere to the east and Ourém to the west offer particularly attractive conditions. These locations combine favorable terrain with good access to existing electrical infrastructure and transportation networks. The slightly elevated position of these areas also provides natural drainage advantages and reduces the risk of flooding during Portugal's wet winter season.

Areas closer to the Nabão River valley floor, while flatter, may be less suitable due to higher moisture levels, potential flooding risks, and the presence of more valuable agricultural land. The steeper hillsides to the north and northeast, while offering good solar exposure, present greater construction challenges and potential visual impact concerns given their proximity to Tomar's historic center and the famous Convent of Christ.

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

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.