Solar lighting is an ecological and economical solution for street lighting and private areas such as gardens. Solar street lamps, equipped with LEDs and photovoltaic panels, are self-sufficient and usesolar energy to provide light. These intelligent lighting solutions are suitable for a variety of applications, including parking lots and remote areas without access to the electricity grid.
The principle of solar street lighting
A typical solar streetlight comprises a solar panel, an LED lighting system, and a NiMH battery to store the energy produced by the solar panels. Solar streetlight installation is straightforward, often designed as a “plug & play” system. LEDs provide maximum light with minimum energy consumption.
To estimate the size of solar panels and batteries required for a solar lighting system, it’s essential to take into account several parameters, such as the desired light intensity, the duration of lighting per night, the number of days of autonomy and local weather conditions.
Let’s take the example of a 40-watt (W) LED solar streetlight that needs to operate for 10 hours a night and have 3 days of autonomy.
- Calculation of daily energy consumption: luminous intensity (40 W) × duration of lighting per night (10 h) = 400 Wh (watt-hours).
- Calculation of energy required for days of autonomy: Daily energy consumption (400 Wh) × Number of days of autonomy (3) = 1,200 Wh.
- Battery selection: Deep-cycle batteries are recommended for solar systems. For this example, we consider a lithium-ion battery with 80% discharge capacity. Battery capacity = Energy required for days of autonomy (1,200 Wh) / Discharge rate (0.8) = 1,500 Wh.
- Solar panel sizing: To determine the size of the solar panel, we need to take into account the daily energy required and the average amount of sunshine in the region. Let’s assume average daily sunshine of 4 hours. Solar panel power = Daily energy consumption (400 Wh) / Average sunshine (4 h) = 100 W.
So, for our example, we would need a 100 W solar panel and a 1,500 Wh battery to properly power a 40 W LED solar streetlight operating 10 hours a night with 3 days autonomy
Solar street lighting installations
In France, cities such as Lyon and Pierre-Bénite have adopted solar street lighting, helping to reduce carbon emissions and energy costs. Solar lighting is also used in Europe and in developing countries such as Congo and Cameroon, where access to electricity can be limited.
Here are a few examples of solar street lighting installations in France:
- The city of Nice, on the Côte d’Azur, has deployed solar streetlights on its famous Promenade des Anglais. These lampposts are equipped with solar panels and batteries to provide autonomous, economical lighting.
- As part of its sustainable energy action plan, Bordeaux has installed solar streetlights to light some of its streets, parks and gardens. These installations help reduce energy consumption and greenhouse gas emissions.
- Montpellier has also installed solar streetlights in several parts of the city to improve public lighting while reducing energy costs.
- La Réunion has set up an ambitious project to install 10,000 solar streetlights in rural and urban areas to improve lighting quality and reduce energy consumption.
In addition to these examples, many other French towns and cities, such as Paris, Lyon, Toulouse and Marseille, have also begun to integrate solar street lighting into their urban and regional planning schemes.
The benefits of solar street lighting
The boom in solar LED streetlights and stand-alone solar lighting solutions is due to the many advantages they offer, such as durability, low running costs and independence from the electricity grid. Information on these systems is increasingly available, enabling individuals and businesses to make informed decisions about adopting this clean, renewable technology.