Solar energy is being well accepted as a green alternative compared to fossil fuels and is recognized to be one of the best renewable sources of energy. Solar street lights can be the most suitable substitute over traditional street lights as they offer a low-maintenance and cost-effective operation with easy installation and optimum lighting. We are blessed with solar energy in abundance which can be intelligently employed for the benefit of the world.
Components of Solar Street lights
The main components of a solar street light system are:
- Solar Panel
- Rechargeable battery
- Lighting fixture
- Interconnecting cables
Working of solar street lights
Solar lights work on the simple principle of photovoltaic effect. Solar panels absorb the energy from the sun and charge the battery during the day. At dusk, these panels work as photo cells and communicate with the electronic controls and turn on the lights. The lights remain on with the help of control electronics till dawn and this process repeats every day where the battery gets recharged and the LED continues to light up. It is important that no shading falls on the panel as it can cause the panels to not charge fully, causing the batteries to not receive the required charge to operate again the following night. Depending on the weather conditions, the battery may charge differently.
The process of solar panels gathering clean renewable energy in the form of sunlight and converting that into electricity is called a photovoltaic effect. Mono-crystalline or poly-crystalline solar panels are typically used in a solar street lighting system. All-in-One solar street lights do not require separate installation of solar panels as the panel is integrated along with the rest of the components as a single unit. For integrated and semi-integrated solar lights, the solar panels need to be fixed as per the manufacturer’s guidelines.
Batteries are used as a storage unit to reserve the energy produced by solar panels, which powers the lights throughout the night. Lithium-ion or LiFePO4 batteries are used in modern solar street lights. On a non-sunny day, batteries with high efficiency play a crucial role to help the solar-powered street lights to sustain their brightness. Even when the solar panels do not provide much output, the lights receive sufficient amount of power to light up. In latest solar street light designs, the batteries are included in the light fixture itself and require very little maintenance.
Solar Charge Controller
Solar charge controllers act as a regulator controlling the power going from the PV panels to the batteries. They also prevent overcharging and stop reverse power flow. PWM or MPPT charge controllers are used in a solar street lighting system. Temperature conditions, cost, size of the system and array to load ratio are a few factors to consider while choosing the appropriate controller for your solar street light. Solar charge controller is a protective device which helps in prolonging the life of the batteries to bring out the best performance from your solar street lights.
Advancement in LED technology has made way to many lightweight and decorative street lighting options. LED lights are the most popular choice for solar street lights due to their excellent lumen output and they consume very less energy. LED lights are considered to be the best in lighting public spaces because of their better CRI (Color Rendering Index) and CCT (Correlated Color Temperature) when compared to other types of lighting fixtures. ABS plastic or metal alloy is used to build the housing of a solar street light fixture.
The entire lighting fixture with in-built battery and the solar panel are fixed on top a pole with the help of sturdy brackets. The pole must be strong enough to hold the entire solar street light system to help facilitate adequate street lighting. The poles are treated and preserved properly before being used and thermally galvanized steel poles typically last for close to 40 years without rusting. After attaching the entire fixture onto the pole, the pole is hoisted and secured at the base with concrete.
There is very minimal cabling to be done to connect the LED light and the solar panel. The length of the cables could vary depending on the height and circumference of the pole. The entire light fixture is attached to the pole with the cables connected before the pole is pulled up. You are usually provided with an installation manual with specification of the cables and the procedure to connect them. The installation process is quite simple and you may be able to do it yourself with basic tools and minimum assistance.
All the components of a solar street light system have IP65 waterproofing since the purpose of solar street lights is to brighten your outdoor space. The design and shape of the solar street lights may vary but the components in all the solar street lights are quite the same. Both All-in-One and integrated solar street lights are available in multiple designs and wattage. You may want to purchase a solar street light with highest level of efficiency and understanding the anatomy of solar street lights may help you choose the best at affordable rates to avail maximum output for years to come.