Solar powered street lights represent the perfect illustration of the current technological potential of solar energy. Having been developed in predominantly African, Middle Eastern and Asian environments, this low-cost, environmentally sound and easy to install method of street lighting is now beginning to be adopted by more and more European and American communities.
Solar power is recognized as being an environmentally ‘clean’ form of energy production, but let us examine the concept in more specific detail.
The basic unit for producing energy is obviously the solar panel itself, which is the means by which the energy given out by the sun is converted into electricity. We are all familiar with quite large solar panels, for domestic or industrial use, but the technology has advanced to such an extent that there are currently many different sizes and power outlets available for use.
This wide variety means that one has to be careful to select an appropriate panel for each specific necessity.
On solar powered street lights, the solar panels employed need to be suitable for extreme weather conditions
They must be capable of producing energy even on cloudy days and able to withstand vandalism and attempts at theft (in Spain when solar panels were first introduced on street light fixtures, many were stolen to be converted for use on caravans!). They also need to be economical enough to use in large numbers. It is not uncommon today for these factors to be met with such confidence that a 20 year warranty is offered on the very best solar panels.
The solar panel itself will be connected to a solar controller – a battery charger which is automatically topped up by the solar panel linked to a timer or photocell which ensures that the solar powered street lights operate in the hours of darkness. Some specific systems employ a further function whereby the light dims at specific times.
The batteries themselves need to be completely maintenance free and capable of providing enough energy for a period of reserve power should there be some sort of problem with the charger or a prolonged period of bad weather.
There are currently a number of different kinds of lamp commonly utilized in solar street lights, generally dependent on the particular requirements of each individual lighting scheme.
At present Light Emitting Diodes – generally referred to as LEDs – are being seen as the most promising source of light. A number of extra bright or even ultra bright LEDs constitute the actual lamp itself. The benefits of LEDs are considerable. For example, they use far less energy than comparable conventional lamps, have a far longer operating life and give good color rendition.
Other lamps which can be used on solar powered street lights include Compact Fluorescent Lamps (CFLs), which generate a white light and are effective for providing good color rendition and High Intensity Discharge lamps (HID). HIDs can themselves be divided into two categories. The first of these HIDs are the Low Pressure Sodium lamps (LPS), which characteristically give out a yellowy orange light, thereby being unsuitable for situations in which color recognition is important. These lamps can last for up to 18,000 hours. Metal Halide lamps (MH) are HIDs but produce a much cleaner white light, thus making color rendering much clearer.
Both HID and CFL rely on a high voltage, specific current and frequency in order to function whereas LEDs are much more adaptable.
To summarize, therefore, solar powered street lights work by using a solar panel to turn the energy from the sun into dc electricity. An electronic circuit then regulates the voltage to a specific value which charges the battery, which lights the lamp. The lamp itself is managed by a timer or photocell which controls the timing of the lighting. The latest applications of solar powered street lighting can go as far as adjusting the intensity and color of the lights at a given time. Click here for more info
We are able to provide you with our own solutions for all solar powered street lighting schemes and would be delighted to hear from anyone who is currently manufacturing solar powered street lights and associated products, is considering a possible application of solar street lighting, or just wants to find out more about this exciting development.