- Aug 30, 2017 -
Solar lights weren't always capable of such remarkable performance. Since solar powered lightsneed to give off light when the sun is down, they are always limited by the amount of energy they can store. The more efficient the light source they use, the smaller the batteries and solar panels can be. The invention of extremely bright, efficient LEDs made solar lights widely usable... and very popular.
LEDs have been around for decades, often as the little indicator lamps on home electronics. Manufacturers love them for this purpose because they're extremely efficient: putting out quite a bit of light while drawing very little power. This makes it possible for electronic gadgets to last longer on one set of batteries.
Only recently, however, did it become possible to produce white light from these LEDs, or make them bright enough for use as lighting instruments. When the power flows through an LED, particles of light are released from a junction between two specialized materials. The wavelength, or color, of light released from this junction depends on the materials used, and it is always just a single color.
A few years ago, scientists realized it wasn't just possible to make LEDs that were as bright as or brighter than regular bulbs. It turns out that by applying a phosphor coating to an LED chip would turn one color into white light.
Like the original LEDs, these white models offer extremely high efficiency on a lumens-per-watt basis, but they also offer brightness almost comparable to regular lighting fixtures.
Improving the efficiency of LEDs is one more key factor that makes them much brighter than similar lights of other types.
LEDs generally only emit light in one direction. Whereas fluorescent and incandescent bulbs require a light-gobbling reflector in order to focus the light, LEDs are directional by default. Reflectors, if needed, can be much smaller, and integrated into the solid-plastic packages that make LEDs so weather resistant.