About Solar Power PDF Print E-mail
“Solar-Powered Lighting Systems” are basically systems that utilize sustainable and renewable energy of the sun during daytime, and store this energy to provide illumination during the nighttime.

The concept was developed as an application of photovoltaic power generation technology developed in the 1950s; at that time, research in semi-conductors led to the development of photovoltaic cells (also called solar cells), which enabled generation of electricity when subjected to sunlight.
This technology at the time was very expensive, and was used to power satellites orbiting the earth. As photovoltaic technology became more wide-spread, along with manufacturing technology advancements, costs of photovoltaic cells became more and more cost-effective, enabling its integration into other applications with low voltage requirements.
This led to the use of photovoltaic cells as a power source for calculators and watches in the early 1980s.
Further advancement in LED (Light Emitting Diodes) technology, as well as batteries and electronics in addition to the advances in solar panel efficiency, made possible the development of efficient lighting systems that utilize photovoltaics as a renewable clean and independent power source with effective lighting output that can replace existing conventional grid-connected electrically powered lighting solutions.

A solar powered lighting system would typically be composed of the following main components:
  1. Photovoltaic Cell (Solar Panel): Converts sunlight into direct current electricity.
  2. Power Storage: the electrical power generated by the solar panel is stored either in a battery (lead-acid, Li-ion, etc.) or an ultracapacitor.
  3. Control System: to control the charging of the of the battery/capacitor and control on/off status of the lighting system, this could be as simple as a photocell, and as complex as a programmable computer.
  4. Illumination Device: which is the main power load used for lighting, this could be an ordinary incandescent bulb, a gas-discharge bulb, or more commonly an LED illumination unit.
In simple terms, a solar powered lighting system uses the Solar Panel, placed at a location with access to direct sunlight, to generate electricity from the sun during the day time by converting sunlight into DC current, which is stored in a battery or capacitor, at night fall, the control system incorporated in the system detects night time, and switches on the illumination device, channeling electrical power stored in battery/capacitor to power up the illumination device. The control system also detects daytime, switching off the illumination device.