Will new lighting technology save energy?

The past five years have not been kind to the global economies or even nature as we’ve seen countries fail and weather become erratic. Yet in those five years we have seen the introduction of technologies that show great promise to lowering our energy needs. What person hasn’t heard or even used some of the new lighting inventions in the form of CFL and LEDs? The promise for either is longer MTBF, which makes them cheaper in the long run. The soothsayers are telling us that these technologies can save us not only cost, but more importantly, energy.

Most of us have seen a night-time photo taken from a satellite that allows you to easily see that we light up the night in all our big cities — so much so that nearby cities are just one long string of light. Lighting needs are said to use about 20% of our global energy production. So the use of CFL and LEDs can lead to fewer coal-fired power plants and that directly reduces the amount of CO₂ released into the atmosphere, which is good for the atmosphere. The U.S. Energy Information Administration says that in 2011 about 461 billion kWh of electricity were used for lighting by residential and commercial sectors, which equaled about 12% of total U.S. electricity consumption (see www.eia.gov/tools/faqs/faq.cfm?id=99&t=3 for more information).

The Grand Indonesia Tower has about 60,000 square feet of LED arrays. (Courtesy of StandardVision)

It is awe inspiring that we, the design engineers, continue to solve the really tough energy efficiency problems with products like LEDs. A simplistic comparison states that the LED has a life-span of 50,000 h vs 1,200 h for incandescent bulbs (and 8,000 h for CFLs). Additionally, an incandescent bulb producing the typical 800 lumens requires 60-W of power while a CFL uses 13 to 15 W, and an LED lamp needs only 6 to 8 W. For example, the environmental impact (CO₂ emissions) of 30 incandescent bulbs (4500 lbs CO₂ /year) is about 10X more than the same number of LED bulbs (451 lbs/year). These are promising numbers if the comparison holds up. If we are to make any headway from these lighting improvements then we must maintain an equivalent number of lumens produced by LEDs compared to incandescent bulbs.

 Mediamesh is an LED video display wire mesh that is hung from a building façade, making it a giant video screen.(Courtesy ag4)

NY Port Authority bus terminal shows off moving LED display.

But that’s not likely because there is no denying the creative process. We are already using LEDs in innovative ways that weren’t possible with other types of lighting. LEDs are becoming the stained glass of architectural designs. For example, we are covering entire sides of buildings with moving LED displays. That requires energy that we didn’t need or use with incandescent bulbs. I’m not saying we shouldn’t use them, but we may have a net gain of zero energy saved because we will need the same number of energy plants if we plaster the landscape with LEDs. I don’t presume to know the answer, but I do know that we are an ingenious family of man and we will think of something — we just need to be aware of what our technology should and should not do.