Solar street lights are raised light sources which are powered by photovoltaic panels generally mounted on the lighting structure. The photovoltaic panels charge a rechargeable battery, which powers a fluorescent or LED lamp during the night.
[edit]Features
Most solar panels turn on and turn off automatically by sensing outdoor light using a light source.[1] Solar streetlights are designed to work throughout the night. Many can stay lit for more than one night if the sun is not available for a couple of days. Older models included lamps that were not fluorescent or LED. Solar lights installed in windy regions are generally equipped with flat panels to better cope with the winds.[1]
Latest designs use wireless technology and fuzzy control theory for battery management. The street lights using this technology can operate as a network with each light having the capability of performing on or off the network.[2]
[edit]Types
Solar street lights are generally classified into two types.[3]
[edit]Standalone solar street lights
Standalone solar street lights have photovoltaic panels mounted on the structure. Each street light has its own photovoltaic panels and is independent of the other lamps.[3]
[edit]Centrally operated solar street lights
In this type, the photovoltaic panels for a group of street lights are mounted separately. All the street lights in a particular group are connected to this central power source.[3]
[edit]Advantages
· Solar street lights are independent of the utility grid. Hence, the operation costs are minimized.
· Solar street lights require much less maintenance compared to conventional street lights.
· Since external wires are eliminated, risk of accidents is minimized.[3]
· This is a non polluting source of electricity
· Separate parts of solar system can be easily carried to the remote areas
[edit]Disadvantages
· Initial investment is higher compared to conventional street lights.
· Risk of theft is higher as equipment costs are comparatively higher.[3]
· Snow or dust, combined with moisture can accumulate on horizontal PV-panels and reduce or even stop energy production.
[edit]Implementation in the Sunderbans
Solar street lights were installed in the Sundarban Tiger Reserve (STR) in August 2008 and April 2009 with assistance from the Forest Protection Committee and the STR officials. Each household in the region were provided with a home light connection by the WWF so that the people feel responsible for the security of the installed solar street lights.[4]
[editReferences
1. ^ a b "Solar street lights". solarhome.org. Retrieved 2011-07-12.
2. ^ "A New Intelligent Control Terminal of Solar Street Light". ieeexplore.ieee.org. Retrieved 2011-07-12.