| | Solid-State Lighting? | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Lighting applications that use Light Emitting Diodes (LEDs) are commonly referred to as Solid-State Lighting. Major benefits of solid-state lighting systems include: ● Long life - reduced maintenance cost ● Reduced energy consumption - especially when colored light is needed ● Better quality light output - minimum ultraviolet (UV) and infrared (IR) radiation ● Intrinsically safe - low voltage ● Smaller flexible light fixtures - useful for lighting tight spaces ● Durable - no filament to break. | ||||||||||||||||||||||||||||||||||||||||||||||||||
| | Solar Cells(Photovoltaics)? | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Solar cells convert sunlight directly into electricity. Solar cells are the one that are often used to power calculators and watches. Solar cells are made of semiconducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic effect. The performance of a PV cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that make up the cell. | ||||||||||||||||||||||||||||||||||||||||||||||||||
| | LED? | ||||||||||||||||||||||||||||||||||||||||||||||||||
| The LED (Light Emitting Diode) is basically a really fancy diode. Diodes only let current (electricity) to flow in one direction and not the other. LEDs are diodes too, but they have the unique "side effect" of producing light while electricity is flowing through them. LEDs are different from ordinary light bulbs because they do not have a filament to break or burn out. They operate on very low voltage from 2-3 volts, generate very little heat, and are ideal for putting lights into portable equipments and self-contained solar lighting devices. In the simplest terms, an LED is made with two different kinds of semiconductor material: one type that has too many free electrons roaming around inside, and another that doesn't have enough. When an electron from one material (the donor) gets pushed across a thin barrier and gets into tiny spaces in the other (the holes), a photon or particle of light is produced. The color of light depends on a number of factors, including the type of material they make the LED with and the material's quantum bandgap (how much energy each electron needs to pack in order to cross the barrier). A smaller bandgap that fairly weak electrons can cross gives you infrared or red light, while a large bandgap that needs really strong electrons gives you light that has a blue or violet color to it. | ||||||||||||||||||||||||||||||||||||||||||||||||||
| | Ultracapacitor? | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Ultracapacitor is a newly developed technology positioned between the conventional capacitors and the rechargeable batteries. Ultracapacitors offer a shift in thought, circumventing the battery scramble, and instead attempt to elicit greater efficiency from existing power sources. Ultracapacitors are free from the characteristic battery problems of limited cycle life, cold intolerance, and critical charging rates. It is also environmentally friendly, helps conserve energy, and enhances the performance and portability of consumer devices. Ultracapacitors can replace batteries in outdoor solar-lighting products. Although its energy less compared to a battery, it's enough to light up the garden, drive away, garden path or any place. The ultracapacitor is much well suited over batteries in solar lighting products: Because an ultracapacitor transfers electrical charges between conducting materials, it can be charged and discharged almost indefinitely, which lead to remove annoying maintenance problem, whereas few batteries, using chemical reactions, can last 1000 cycles. In addition, the ultracapacitor can also be charged effectively regardless of weather condition. | ||||||||||||||||||||||||||||||||||||||||||||||||||
| | Ultracapacitor VS Battery for Solar Lighting System | ||||||||||||||||||||||||||||||||||||||||||||||||||
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