The lightbulb that has supplied our homes and offices with light since the 1880s is officially on its way out. Incandescent light bulbs while cheap, are very inefficient. In fact, most of the energy they produce is wasted as heat. As a result the financially and ecologically concerned are ditching incandescent bulbs for LEDs. The LED, or light-emitting diode, has been around for years. They light up cellphone screens, Christmas lights, and traffic signals. However, LEDs have never really taken off as far as household lighting goes. In the last few years, though, LED replacement bulbs that screw into lamps like incandescent bulbs have become more common. While LEDs are more expensive than incandescent bulbs, they offer better light quality and greater flexibility. In some ways, LED light bulbs can be considered a perfect technology.
An LED is known as a “solid-state lighting” technology or SSL. Instead of emitting light from a vacuum like an incandescent bulb, an SSL emits light from a solid piece of matter. In an LED, light is produced when electrons move around in the semiconductor structure, which is made of positively and negatively charged components. The positive component is composed of holes that allow electrons to flow through them, and the negative layer is made of free electrons floating around in it. When an electron strikes the semiconductor, it activates a flow of electrons from the negative to the positive layer. The excited electrons emit light as they travel through the positively charged holes. This solid-state lighting technology has allowed LED light bulbs to become the superior choice in lighting. While you won’t find LED light bulbs in too many household fixtures today, there are a number of reasons to make the switch from incandescent.
First, there is the reduced energy use. The SSL method of producing light loses far less energy to heat than other lighting technologies do. As a result, it is about 85% more efficient than the vacuum/filament method used in incandescent bulbs. The vacuum/filament method causes incandescent bulbs to be extremely inefficient because most of the energy is lost as heat as electricity is pumped into filaments to make them glow. While a light fixture with a 60-watt incandescent light bulb consumes about 525 kWh of electricity in a year, an LED Geo-bulb in the same fixture only uses 65 kWh in annual energy use. That makes the LED an energy-efficient choice. Also, the carbon dioxide reduction for LED lights is in the hundreds of pounds for a single lamp. The reduction in carbon dioxide production and energy usage make it easy to see why LEDs have emerged as popular green lighting.
But energy efficiency is just part of the story. The other part is time efficiency. Solid-state lights such as LEDs are more stable light sources than incandescent bulbs. It is possible to go 20 years without having to change an LED light bulb. In fact, a Geo-bulb lasts 30,000 hours while a typical incandescent lasts about 750. LEDs are so long lived because they do not operate at high temperatures like incandescent bulbs. These high temperatures degrade the filaments used to produce light in incandescents making the bulbs useless in a relatively short period of time. Even though LED lights are more expensive than the 1 or 2 dollar incandescent bulbs, the switch to LEDs is worthwhile in the end. Tariq Syed, a machinist at an electrical utility, who was interviewed by the New York Times, said, “The LED you buy, even though you pay even $25 or $30, it’ll last like nine or 10 years.” As a result, LEDs will end up saving money in the long run because the bulbs only need replaced once every decade or two.
Aside from the cost, another primary concern with LEDs is the color of the light emitted. All of the light produced by an LED is the same color and LEDs can be designed to produce light within the visible range of the spectrum. This precise conversion of light to one color is why LEDs are referred to as “digital light.” This digital precision creates a problem. Our eyes prefer full-spectrum light, such as the light produced from an incandescent bulb, a fireplace, or the sun. Today, LED bulbs use a mix of phosphors, which absorb light and re-emit it at different colors, to convert the single color of the LED to multiple colors that mimic the spectrum. As a result, more people find the light of the LED pleasing while a number of them prefer the color of light emitted by incandescent bulbs.
LED light bulbs can be considered a perfect technology. Compared to the incandescent light, the design and SSL technology behind the LED bulb makes it a superior choice in lighting. The next time its necessary to change a light bulb consider buying an LED bulb, especially if you are looking for a way to save a few bucks and the environment at the same time.