Solar PV Analysis of Rennes, France
The location at Rennes, Brittany, France is decent for generating solar energy throughout the year, but it's not perfect. The amount of electricity produced by solar panels varies across seasons: it's highest in summer and spring, with around 5.52 and 5.21 kilowatt-hours (kWh) generated per day from each kilowatt (kW) of installed solar capacity respectively. In autumn, the output drops to about 2.90 kWh/day per kW; in winter it's even lower at only about 1.36 kWh/day per kW.
This means that the most ideal times to generate solar power in Rennes are during the longer daylight hours of spring and summer when sunlight is plentiful. During autumn and winter when days are shorter and there might be more cloud cover or foggy weather conditions, less electricity can be generated from the sun.
When installing your fixed panel solar system here, you should tilt your panels towards south at an angle of 41 degrees to get as much sunlight as possible throughout all seasons.
However, local factors such as weather conditions could affect how much energy you can produce from a solar installation in Rennes. For instance, this area experiences significant rainfall throughout the year which could obstruct sunlight reaching your panels thus reducing their efficiency.
To mitigate this issue, make sure to clean your panels regularly especially after heavy rainfalls or storms to remove any dirt or debris that may have accumulated on them so they can continue absorbing maximum sunlight efficiently for power generation.
Furthermore consider installing a monitoring system which will alert you if there’s a sudden drop in energy production indicating potential issues like shading on part of your system due to new obstructions like growing trees or new buildings nearby so they can be addressed promptly ensuring greater energy production from your installation over time.
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 Rennes
Seasonal solar PV output for Latitude: 48.11, Longitude: -1.6744 (Rennes, 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 Rennes, France
To maximize your solar PV system's energy output in Rennes, France (Lat/Long 48.11, -1.6744) 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 Rennes, 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 Rennes, 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 |
|---|---|---|---|
| 32° South in Summer | 51° South in Autumn | 62° 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 Rennes, 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 Rennes, France.
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 Rennes, France
Rennes, the capital of the Brittany region in northwestern France, is located on a plateau. The topography around Rennes is characterized by relatively flat or gently rolling landscapes with some hills. The city itself is situated at an average altitude of 30 meters above sea level.
The surrounding areas are primarily agricultural lands comprising fields and pastures, interspersed with small patches of forests. There are also several rivers and streams in the vicinity.
Regarding large-scale solar PV installations, open and flat terrains like agricultural land would be ideal as they provide ample space for such projects while minimizing installation challenges associated with uneven terrain. However, it's important to consider other factors too such as local climate (solar irradiance), land use regulations, proximity to power grids for energy transmission etc.
Moreover, Brittany has a temperate maritime climate which means it gets less sunshine compared to southern parts of France but still receives enough sun for viable solar power generation.
In terms of specific locations near Rennes suited for large-scale solar PV installations:
1) Areas south-east towards Vitré could be suitable given their expansive agricultural fields.
2) North-western regions towards Saint-Malo also have considerable open spaces that might accommodate large scale solar farms.
3) Lands along major highways like A84 could potentially host linear solar parks similar to those seen alongside railways or motorways in other countries.
However any development must take into account environmental impact assessments and local planning regulations before proceeding.
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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Article Details for Citation
Author: Aaron Robinson
Publisher: profileSOLAR.com
First Published: Wednesday 15th of May 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.
