Long gone are the days that we leave all the lights on in our homes, never giving a thought to how much energy they are consuming, or how much heat they are producing. Today we are asking if LED lighting will become one of the most important ways of conserving electricity. Is it really possible that such a small change in the way we do things could have such a huge impact on our National Energy Consumption?
First, a brief history of the light bulb.
Naturally, we equate 1879 and Thomas Alva Edison with inventing the light bulb, but in fact it was 1802 and Humphry Davy who first produced electric lighting. His first invention was an electric battery, and to this he connected a piece of carbon. The carbon did glow, tho not for long, and it was too bright to be practical. His invention was called the Electric Arc Lamp. For the next 70 years, many inventors worked on the electric light concept, using various configurations of different metals. In 1840 Warren de la Rue, a British scientist, fashioned a bulb from platinum filament in a vacuum tube; when he ran electricity through the filament, he produced a quality light, but the cost of platinum prohibited this from being practical for commercial production.
There are several famous light bulbs, ones that have been burning continuously for decades. Most notable is the Centennial Light, which is located in Livermore, California, and maintained by the Livermore-Pleasanton Fire solar power system manufacturer Department. It is said to be over 110 years old. Ironically, the reason that these very old bulbs are still burning is that they are never turned off. It’s the heat/cold fluctuation on the filaments which causes their early demise. The dilemma is, however, that leaving an incandescent bulb burning continuously uses a huge amount of electricity, and 90% of energy use is wasted in heat and not light.
Jump to the 1930s, and suddenly fluorescent lamps were all the rage. They were a savings on electricity, but their harsh, flickering light was hard on the eyes and the nerves. When compact fluorescents, or CFLs, were introduced into the greater marketplace in late 1980s, they began to replace the older fluorescents, as well as many incandescent bulbs in homes. They did, indeed, last many times longer than incandescent light bulbs, were more efficient in the light/heat ratio, and were not prohibitively expensive. Halogen lighting was also becoming popular, with it’s very bright light and low energy use, but the extreme heat emitted could be very dangerous if handled improperly.
Then steps in the LED, or light emitting diode. The definition of a diode is “a semiconductor device with two terminals, typically allowing the flow of current in one direction only.” It was in the 1960s that LEDs were first produced, but since they only emit one color of light and that color was red, they were used mainly by the military. In today’s application, the red LED is an excellent night time light for camping, hiking, or doing chores, for it is not bright enough to cause the iris to close, but bright enough to give quality night time vision. Additional colors were created in the 1970s, where they became popular in watches, calculators, testing instruments and more.
Enter the 1980s, when many advancements in LED technology gave rise to light that was over 10x brighter and 10x more efficient than neon, incandescent, and CFLs. This led to a boom in the lighted sign industry, where brightness did not have to be sacrificed because of energy costs.
The 21st Century has seen LEDs become the standard in such large applications as traffic lights, hazard signs, and pedestrian crossing signals, down to the smallest LED on a computer, iPod charger, or USB hub. The colors and applications seem to be endless, and new ones seem to pop up daily.
Here is where the big savings are starting to kick in. For instance, the city of Colorado Springs, Colorado decided to retrofit all of their street lights. The city was spending $3.2 million each year for street lights, and when the budget restraints became untenable, it was decided to turn off 8,000 to 10,000 streetlights as one way to save money. This was in 2009. The citizens of the city were not happy when it was their lights which had gone dark. Then in late 2010, the city received a federal Energy Efficiency and Conservation Block grant, and they were able to retrofit all the street lights to high efficiency LEDs. It was estimated that the retrofit would have a price tag of $10 to $15 million; however, that retrofit would then save an estimated 40 percent of the operating costs. In well under 10 years, the savings to the city will more than pay for the retrofit, and with the approximate life of the bulb being over 10x that of the traditional bulb, the savings will continue for decades to come. Add to that the ”night skies compliant” factor of LEDs, and it is a win for everyone.
And how do these savings translate to the home owner?
White LED bulbs were developed in Japan in the late 1990s. This whiter light is close to the visible light spectrum, and therefore very much like true daylight. The higher power also makes these LEDs extremely efficient, since nearly all of the electricity is converted into light and not heat. Even though these bulbs are quite spendy, their pure light, lack of heat, and very long life more than justifies the initial cost. And for those who live off of the grid, low wattage high lumen lighting is even more crucial.
In a US Department of Energy bulletin, it was estimated that a 40 watt incandescent light bulb would cost about $5.25 a year to use about 3 hours a day, but would die after just over 2 years of use. Because they only cost about $1, no one thinks much about tossing the old and putting in the new.
A typical high quality LED light could cost as much as $50 or more. However, it only uses 5 watts of power to produce the high lumens, a measurement of the quality of visible light, necessary for reading, work stations, kitchens, and other applications where bright light is a must. Using the same 3 hours per day, the yearly electricity cost is $.65, or 1/8 of the usage of the incandescent bulb. These solid state LEDs have a very long life, 50,000 hours or more. This translates into a life of 45 years when burned 3 hours a day. Let’s say that the cost of utilities never goes up {ha!}, the cost of running an LED for 45 years would be just under $30. The cost of running the incandescent would be just over $236. Subtract the cost of 23 bulbs at $1 each, and that leaves a ”balance” of $213. Now add the cost of the $50 LED bulb to the $30 electricity cost of the LED bulb, and you have a ”balance” of $80. Finally, multiply this by the number of light bulbs in a typical home, about 45, and the price of electricity can be staggering.
