Blois, France, located in the Northern Temperate Zone, presents a moderately favorable location for year-round solar PV energy generation, though with significant seasonal variations that potential solar installers should carefully consider.

Seasonal Solar Performance

The solar energy output at Blois shows dramatic fluctuations throughout the year. Summer delivers the strongest performance at 5.73 kWh per day per kW of installed capacity, making it the peak season for solar generation. Spring follows closely behind with 5.14 kWh per day per kW, creating an excellent six-month period from roughly March through August for solar energy production. However, the location faces considerable challenges during the cooler months. Autumn production drops significantly to 2.97 kWh per day per kW, while winter presents the most challenging conditions with only 1.41 kWh per day per kW of output. This represents a four-fold difference between peak summer and winter production levels.

Optimal Installation Configuration

For fixed panel installations at Blois, the ideal tilt angle is 41 degrees facing south to maximize total year-round solar production. This angle is calculated by analyzing daily solar elevation angles throughout the year and weighting them according to solar irradiance data to achieve the best annual average performance.

Local Factors Affecting Solar Production

Several environmental and weather factors in the Blois region can significantly impact solar energy production:

• Frequent cloud cover and overcast conditions - The Loire Valley region experiences considerable cloudiness, particularly during autumn and winter months
• Morning fog and mist - The proximity to the Loire River creates humid conditions that often result in morning fog, reducing early-day solar capture
• Dust and pollen accumulation - The agricultural surroundings and tree-lined landscape contribute to panel soiling, especially during spring months
• Snow and ice formation - Winter weather can create ice buildup on panels, blocking sunlight and reducing efficiency

Preventative Measures for Enhanced Performance

To maximize solar energy production despite these challenges, several installation strategies can be implemented. Installing panels with adequate spacing and ventilation helps prevent moisture buildup and allows for better air circulation. Regular cleaning schedules, particularly during high-pollen spring months and after dusty agricultural activities, will maintain optimal panel efficiency. Choosing panels with anti-reflective coatings and hydrophobic surfaces can help shed moisture more effectively and reduce the impact of morning fog. Installing panels at the recommended 41-degree angle not only optimizes sun exposure but also promotes natural cleaning through rainfall and reduces snow accumulation. Consider implementing monitoring systems that can detect performance drops due to soiling or weather-related issues. This allows for timely maintenance interventions. Additionally, ensuring proper drainage around the installation site prevents water pooling that could create localized humidity issues affecting panel performance.

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 627 locations across France. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.

Link: Solar PV potential in France by location

Solar output per kW of installed solar PV by season in Blois

Seasonal solar PV output for Latitude: 47.5967, Longitude: 1.3261 (Blois, France), 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 41° South in Blois, France

To maximize your solar PV system's energy output in Blois, France (Lat/Long 47.5967, 1.3261) throughout the year, you should tilt your panels at an angle of 41° 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 Blois, France

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 Blois, France. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 41° 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	51° South in Autumn	61° South in Winter	40° 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 Blois, France

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 Blois, France.

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 Blois, France

Topographical Features Around Blois

The landscape surrounding Blois presents a gently rolling terrain characteristic of the Loire Valley region in central France. This historic city sits on elevated ground overlooking the Loire River, positioned on limestone bluffs that rise approximately 70 meters above the river level. The topography consists primarily of undulating hills and plateaus, with the Loire River valley creating the most significant geographical feature in the immediate area. The region displays a relatively modest elevation profile, with most areas ranging between 80 and 150 meters above sea level. The Loire River meanders through the landscape from east to west, creating fertile floodplains on either side of its course. North and south of the river, the terrain gradually rises into gentle slopes and plateaus that extend toward the Beauce plain to the north and the Sologne region to the south. The geological foundation consists primarily of limestone, chalk, and clay deposits, which have been shaped over millennia to create the characteristic Loire Valley landscape. Small tributaries and streams have carved minor valleys throughout the region, but these features are generally shallow and do not create significant topographical obstacles.

Optimal Areas for Large-Scale Solar Development

The elevated plateaus extending north and south of Blois offer the most promising locations for large-scale solar photovoltaic installations. These areas provide several advantages including relatively flat terrain that minimizes grading requirements and reduces installation costs. The limestone plateaus north of the city, particularly those extending toward the Beauce agricultural plain, present expansive open areas with minimal natural obstructions. The southern plateaus toward the Sologne region also demonstrate excellent potential, though careful consideration must be given to existing forest cover in some areas. These elevated positions benefit from reduced atmospheric interference and excellent exposure to prevailing weather patterns that bring clear skies from the southwest. Agricultural areas on the gently sloping terrain between 100 and 140 meters elevation represent ideal compromise locations. These sites offer sufficient elevation to avoid potential flooding concerns while maintaining accessibility for construction and maintenance activities. The moderate slopes in these areas, typically ranging from 2 to 5 degrees, can actually enhance solar collection efficiency when panels are oriented appropriately. Areas immediately adjacent to the Loire River valley floor should generally be avoided for large installations due to periodic flooding potential and the presence of valuable agricultural land. Similarly, the steeper slopes immediately surrounding Blois itself present challenges for large-scale development, though they might accommodate smaller distributed installations. The region's infrastructure accessibility represents another significant advantage, with major transportation networks providing excellent access to potential solar sites. The relatively stable geological conditions and well-drained soils on the limestone plateaus minimize foundation concerns and reduce long-term maintenance requirements for ground-mounted systems.

France solar PV Stats as a country

France ranks 11th in the world for cumulative solar PV capacity, with 14,718 total MW's of solar PV installed. This means that 2.80% of France's total energy as a country comes from solar PV (that's 30th in the world). Each year France is generating 218 Watts from solar PV per capita (France ranks 23rd in the world for solar PV Watts generated per capita). [source]

Are there incentives for businesses to install solar in France?

Yes, there are several incentives for businesses wanting to install solar energy in France. The French government offers a range of financial incentives and tax credits to encourage businesses to invest in renewable energy sources such as solar power. These include the Feed-in Tariff (FiT), which pays businesses for the electricity they generate from their solar panels, and the Investment Tax Credit (ITC), which provides a 30% tax credit on investments made in renewable energy systems. Additionally, businesses may be eligible for grants or loans from local authorities or regional development agencies.

Do you have more up to date information than this on incentives towards solar PV projects in France? 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.