Solar light
As solar lights electric lamps are designated by solar energy are fed.
Photovoltaic solar modules are used in all cases to convert solar energy into electrical energy . Various types of incandescent lamps as well as fluorescent lamps or LED elements are used to generate light .
Basics
Since solar energy is only available during the day and the light is only required after sunset, the electrical energy generated must be temporarily stored. These are batteries used. Charging is usually carried out via a charge controller in order to avoid damage to the batteries from charging and discharging currents.
The light source always forms a structural unit with the accumulator and charge controller . The solar module is mostly separate from it. It can then be installed outdoors while the luminaire - connected to the module via a plug connection during the day - is available for mobile use in the evening. That is why photovoltaic lights in house systems (“Solar Home Systems”) are not referred to as solar lights.
The various devices available on the market differ in terms of light intensity, light duration and charging time. These key data must be weighted differently depending on the intended use of the luminaire.
Applications
The first mass-produced solar lights, mostly called camping lights, came onto the market in the 1980s in the USA, Japan, China and various European countries. At first they were mainly sold on leisure markets. Garden lights were added later as a notable market segment in their own right, which, with very low output, are mostly used for orientation at the wayside in the garden. The currently most important field of application is that of mobile solar lights for off-grid regions in developing countries. In the past, solar lights were often equipped with energy-saving lamps, while high-performance LEDs have now established themselves because they are much more efficient.
- Photovoltaic powered camping lights are used for camping as well as in off-grid homes and huts and at various leisure events. The luminous fluxes I are mostly between 100 and 250 lumens , the maximum burning hours (autonomy A) between 0.5 and 10 hours.
- Garden lights are intended for stationary use. Together with a small module, they are designed as a structural unit and are firmly positioned. Their brightness is usually very low, so that they are more suitable as a guide than as path lighting.
- Solar lights for developing countries are similar to camping lights, but are designed for tougher requirements and for a longer service life even under unfavorable conditions. Solar lights are superior to the lighting equipment commonly used in developing countries , such as kerosene lamps and candles, in ecological and health aspects, but they are unaffordable for many people living there. However, with the rise in the price of fossil fuels , this situation is changing. In addition, the use of solar lights is promoted by government and charitable initiatives. In addition, the solar modules of the solar lights are used to charge the batteries of cell phones or to operate small radios .
Solar lamp with 1.5W module
Solar lamp (kit) with 2.5W module
The solar cell of a garden lamp
literature
- Udo Rindelhardt: Photovoltaic power supply . Teubner, Stuttgart 2001, ISBN 978-3-519-00411-0 .
