The Advantages and Disadvantages of Solar Street Light
Solar power is energy from the sun that is converted into thermal or electrical energy. Solar power is a kind of inexhaustible and environmentally-friendly new energy resources. The solar street light is one of the applications of solar power.
Solar street light has the advantages of stability, long service life, simple installation, safety, great performance and energy conservation. This kind of light can be widely installed in urban roads, living districts, factories, tourist attractions and parking lots.
The solar street light consists of LED light source, solar panels, storage battery, solar charge controller, lamp-post and accessory wire rods. Generally, the solar module is made of monocrystalline silicon or polycrystalline silicon. The storage battery is placed underground or in the specialized battery incubator. The battery is generally valve-regulated lead-acid battery, gel battery, iron-aluminum battery or lithium battery. The controller is placed in the lamp-post. It has the function of overcharge protection, overdischarge protection, trickle charge protection, reverse-connection protection, undervoltage protection, light control and time control. In a word, the major function of solar charge controller is protecting the storage battery.
Solar Street Light Operating Principle
In the daytime, solar panels absorb the sunlight and convert it into electricity under the control of solar charge controller. Solar modules will charge the storage battery. At night, the storage battery supply electricity to LED light source. DC controller can ensure that the storage battery will be protected from damage due to overcharge or overdischarge.
The installation of solar street light is simple and convenient without complicated new wiring. It only needs a concrete base and a battery pit. The installation doesn’t need a lot of labor forces, materials and financial resources.
2、Energy-saving and environmentally-friendly
The solar street light converts the sunlight into electricity without electricity consumption. It produces no pollution and no radiation, which conforms to the present environmental protection concept.
3、Safe and durable
The traditional street light may have hidden safety hazards due to construction quality, material aging and power supply disorder; while the solar street light does not utilize the alternating current so that it will not have hidden safety hazards. Nowadays, most solar modules in the market have stable performance for at least ten years due to the mature manufacturing technology. They can generate electricity for twenty-five years or even longer.
4、High technology and low maintenance costs
Regulated by solar charge controller, the solar street light can adjust the light intensity according to the natural brightness and people’s demand. In the remote regions, the maintenance cost for traditional street light is high. However, the solar street light only needs cyclical inspection, thus the maintenance cost is relatively low.
Due to the traditional energy shortage, the application of solar power will be wider. The photovoltaic industry has been an emerging industry these years. The solar street light has been applied to a lot of situations. However, there are also some restraining factors in the application and promotion of solar street light.
1、Large initial investment
One of the factors is the input cost. The initial investment of solar street light is large. According to the survey, the total cost of installing a solar street light is three or four times of the cost of traditional street light with the same efficiency.
2、The service life of storage battery
Generally speaking, the common storage battery can not reach full charge in one year or even half a year. The practical charging efficiency of some of them may decline to 50％, which will definitely influence the lighting condition at night during the continuous raining days. Therefore, it is essential to choose a kind of high-quality battery in installing a solar street light.
4、The low conversion efficiency
The conversion efficiency of solar panels is almost 15%~19%. Theoretically, the conversion efficiency of silicon solar panel is up to 25％. However, this efficiency will be influenced by the buildings around the solar street light.
5、Geographical and weather conditions
The geographical and weather conditions directly influence the lighting condition of the solar street light because the solar power is from the sun. Continuous cloudy and rainy days will affect the lighting, thus the illuminance or brightness of the light is not up to the national standard. What’s worse, the solar street light can not light up.
In conclusion, the photovoltaic industry will continue to develop rapidly in the coming years. With the development and upgrading of the technology, solar street light will be applied much widely.