LEDs are lighting the way to our future

Lighting experts expect that light-emitting diode lights will soon completely eliminate fluorescent lighting and that LEDs will reduce the use of incandescent lighting to a few specialty items like high-powered outdoor halogen lamps. This shift is expected to be nearly complete by 2030. Further improvements in LEDs, including a shift to what should ultimately be lower-cost organic LEDs are likely to continue. By 2050, all new lights may be LEDs or OLEDs.

This change means that we’ll use less energy for better quality light – and it also means that we’ll get additional savings through the reduction of total materials and labor needed to build new and replace old, lights. LEDs will also offer other capabilities that haven’t ever been available to the average person. An average homeowner will be able to set timers, dim lighting, change the color of lighting and even change the “color temperature” of lighting (the relative proportions of blue and yellow in a nominally white light). Elimination of blue wavelengths in the evening is expected to have significant, positive health effects.

Let’s take a look at a couple of easily understood examples, each of which shows cost advantages of LEDs beyond their very significant energy savings.

Forty years ago, 40 watts was a common size for the light bulb in an exit sign – the type you see over the door in non-residential buildings. If you leave a 40 Watt incandescent light bulb on 24 hours a day, it uses 350 kilowatt-hours (kWh) a year. Here in La Conner, that much electricity would cost about $45.

A typical incandescent bulb would need to be replaced about once a year at a cost of about $2 for the bulb, plus the labor associated with bringing out a ladder, unscrewing the face plate, changing the light bulb and putting everything back. If that takes ten minutes and is done by an employee being paid $18 an hour, the labor cost is another $3. Therefore, over 18 years, running an old exit sign would cost $900, including $54 in labor, $36 in materials and $810 in electricity.

Today’s 2-watt LED exit signs use 17.5 kWh a year, at a cost of $2.25 in electricity. A plain, non-decorative model without additional emergency lighting costs about $40. A new LED sign has an expected life of about 6 years. They’re usually hard-wired, so you may need an electrician to replace it at an approximate cost of $50 each time. Over 18 years, insalling three signs at a total cost of $90 each (labor plus materials) equals $270 plus $40.50 in electricity, or $310.50 total – a little under 40% of what the old sign would have cost.

Traffic lights, until about 20 years ago, used 40 watt incandescent bulbs. The red and green lights, each on for about half the hours in a year, lasted about a year and a half. Traffic lights now use 2-watt LED lamps and the red and green lamps each last around ten years. Energy savings per signal are comparable to a single exit sign’s energy savings. The labor savings are more significant. It takes much more effort to run a truck out to intersections to change a traffic light, than it does to change a light above a building’s door.