Solar lamp

A solar lamp also known as solar light or solar lantern, is a lighting system composed of an LED lamp, solar panels, battery, charge controller and there may also be an inverter. The lamp operates on electricity from batteries, charged through the use of solar photovoltaic panel.

Solar-powered household lighting can replace other light sources like candles or kerosene lamps. Solar lamps use renewable energy with infinity supply which is cheaper than standard lamps. In addition, solar lamps reduce health risk as kerosene lamps have a bad impact on human health. However, solar lamps may have higher initial cost, are weather dependent.

Solar lamps for use in rural situations often have the capability of providing a supply of electricity for other devices, such as for charging cell phones. American investors have been working towards developing a $10 / unit solar lantern for replacement of kerosene lamps.

In the past solar panels used large crystals mainly made out of silicon which produced electricity when it was exposed to light. When electrons in silicon are exposed to light, they start to vibrate from their fixed positions following thermodynamics rules. Furthermore, it produces heat from the vibration and the movement. Through this, silicon turns a large portion of light energy into electricity. However, manufactures found silicon too expensive to make and to put in as a component of solar lamps.

Photoelectric effect used in solar cells was first noted by Edmond Becquerel, a French physicist, in 1839. Albert Einstein won a Nobel prize in 1922 by exploring the nature of light and the photovoltaic technology based on photoelectric effect. The first photovoltaic module was built in 1954 by Bell Laboratories.

On the other hand, nowadays solar panels are made out of smaller and cheaper crystals. For example, copper, indium, gallium and selenide. These new crystals can be used to form thin flexible films. However these cheaper crystals are less efficient at turning light energy into electricity. Therefore, it is an ongoing project to find a cheaper, efficient silicon substitute material that can be easily mass-produced and convert light into electricity very easily.

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Wikipedia