Cover Story

The Light Bulb of Tomorrow

LED Technology Casts a Brilliant New Light on the Future of Energy Efficiency

Story and Photos by Doug Cochran, Contributing Writer

 


LED light bulbs offer energy-cost savings that you can bank on for an entire generation!

The little red light has grown up, and a new generation is on the horizon.

That tiny red bulb you’ve seen for years on transformers, camcorders and electronic devices — the LED — is about to revolutionize the way we light our homes and businesses.

That little red light is no longer just red. Or little. LEDs, or light-emitting diodes, now come in every color in the rainbow — and some that are not even visible to the human eye. More importantly, LEDs have grown brighter, they are proving to last a long time — a very long time — and they are stingy in how they use electricity.

That last quality, the efficiency of the LED, happens to be extremely important right now. Although it wasn’t particularly noticed at the time, federal legislation in 2007 set new and much tighter efficiency standards for light bulbs.

“This legislation is going to essentially begin to remove incandescent bulbs from the market,” explains Catherine Powers, vice president of forecasting & member services for Old Dominion Electric Cooperative (ODEC). “The bulbs we’ve known for a hundred years are going to start disappearing from store shelves.”

These new rules, which will begin phasing in next year, don’t explicitly ban any particular type of bulbs. However, the very nature of incandescent light bulbs means it will be almost impossible for manufacturers to make them efficient enough to meet the new standards.

Most experts believe Americans will have to start turning to more efficient alternatives — compact fluorescent lamps (CFLs) and LEDs. CFLs, the compact fluorescent bulbs that already crowd store shelves, will generally meet the new standards and will last several times longer than traditional bulbs, but they are not without a few issues of their own. Many CFLs emit a light that is bluer, or “colder,” than people are used to, and the safe disposal of these bulbs has raised some concerns. Most CFLs contain trace amounts of mercury.

Safe, Long-lived, Versatile

LEDs, on the other hand, are not only safe to discard, they last so long that throwing them away simply does not occur that often. And they are efficient, far more efficient than incandescent bulbs. Many are significantly more efficient than CFL bulbs.

“It’s really pretty simple,” reports Erin Puryear, ODEC’s manager of energy innovation planning. “LEDs are extremely energy efficient, extremely long lasting, and extremely versatile. We think they’ll play a huge role in how we light homes and businesses in the future, and how we save energy.”

Traditional incandescent lights, the kind we’ve used for more than a century, force electricity through a small wire, or filament. The filament gets white hot and emits light — and a lot of heat. In fact, most of the electricity used by an incandescent bulb is actually given off as heat.

The LED is different. In reality it is a tiny bit of a semiconductor material — the kind of material in computer chips, mixed with specific chemicals. Just a little electricity causes the LED to glow in a process called electroluminescence. Since little heat is produced, LEDs produce a lot more light for each unit of electricity — they are much more energy efficient.

LEDs have enormous potential, according to the U.S. Department of Energy. The DOE projects that the use of LED lighting alone in 2030 will lower U.S. energy demand by 194 billion kilowatt-hours, or by the total annual power output of more than 28 generating stations the size of ODEC’s 850-megawatt Clover Power Station. The energy cost savings in that year alone will be $15 billion, DOE says.

Evolving Technology = Increasing Potential

How can the tiny little LED account for such gigantic savings? “The technology ...” responds Robert Kirkland, utility relations manager at General Electric. “We think the technology is fantastic.” Kirkland speaks with a bit of pride because the first visible-light LED was created by a GE engineer in 1962.

That first LED was red, the ubiquitous glowing red dot that began to appear on electronic devices more than 30 years ago to indicate their status — and even popped up in a grid-like arrangement as the numeric display on early electronic calculators. Eventually, other colors were developed, and LEDs became brighter. In the 1990s the technology began an explosive growth that still continues. DOE says research firms and manufacturers announce a major new generation of LED technologies almost every six months, new technologies that make LEDs even more powerful, and more efficient.

James Broderick, lighting program manager for the DOE Building Techno­lo­gies Program, recalls, “Just five years ago, the best white-light LED was running 20 lumens per watt; now it’s 100 per watt. The efficiency has increased enormously, and we expect that to continue.” The lumen is a measure of light. A 100-watt incandescent bulb is rated at only 17.5 lumens per watt, or five times less efficient.

These new semiconductor lights are not only more efficient than incandescent and fluorescent bulbs, they are also much less subject to being damaged by vibration or dropping, and they last a very long time. While most major lighting manufacturers currently expect their LED bulbs to last at least 25,000 hours — or about 25 times as long as traditional incandescent bulbs — some project these new bulbs may last 50,000 hours or more. In addition, while typical incandescent and CFL bulbs dim significantly as they grow older, LEDs do not.

Experts are calling LEDs a “generational” bulb. Theoretically, if you buy a bulb for your new child’s room, it will still be there and working when that child graduates from college. It can be said to last an entire generation.

Not a Perfect Solution

Yet LEDs are not a perfect solution for all lighting needs. Kirkland says, “The LED is a great solution, but it’s not the only solution. It doesn’t work in all applications.” He notes that efficient halogen bulbs, or CFLs may be better in certain specific uses.

An LED is directional — it produces light that goes in one direction. Traditional bulbs emit light in all directions. Most of the LED bulbs that first appeared on store shelves looked like traditional bulbs, but really threw light only in one direction, like a floodlight. However, manufacturers are now producing bulbs that use many LEDs pointing in many directions — along with reflectors and diffusers — to match the all-around lighting of conventional incandescent bulbs.

And LEDs can’t use the kind of alternating current in most homes and businesses. LED bulbs that fit regular bulb sockets must contain small electronic devices to convert the electricity. Such devices are not a technical problem, but they do raise the cost of these bulbs.

Lisa McLeer, GE Lighting’s marketing manager, reports her company began to manufacture and sell its first omni-directional LED bulb late last year, a 40-watt bulb that uses only 9 watts — but costs $50. Other LED bulbs are now selling for from $19 to $90 each.

While that cost seems high, when you sit down and actually compare different bulbs — how long they last and how much energy they use — LEDs are far less expensive than incandescent and even CFL bulbs. For example, you would have to buy from 20 to 60 traditional incandescent bulbs — or up to 6 CFLs — to have them last as long a one LED bulb.

But the real savings with LED bulbs lies in their energy efficiency. A 40-watt traditional bulb burning 4 hours a day would use almost 60 kwh in a year. At about 12 cents per kwh — an average figure for mid-Atlantic electric customers — that would be about $7 a year. An LED bulb that gives off the same light would use 9 watts, just over 13 kwh or $1.60 a year — a $5 annual savings. The savings would pay for the higher cost of the LED bulb in less than 10 years, yet the bulb would last 30 years. For consumers, LEDs should be a slam dunk.

An Educational Challenge

However, ODEC’s Powers explains the acceptance of LED bulbs by consumers will take work. “LEDs offer a huge potential to save energy and money, but they also present a big customer education challenge.” She notes that LEDs save energy, last decades, and are highly shock resistant, “but this is a whole new technology for us and for our customers.”

Powers notes that CFLs presented the same kind of challenge a decade ago as customers learned what to look for in a new technology, and how to best use it. She urges co-op customers to learn about the new LED lights in the same way, to look for bulbs by major manufacturers, and those with the ENERGY STAR rating.

“We’re going to continue to work with manufacturers to keep up with this growing technology, and to share what we learn with customers,” Powers says. She also indicates cooperatives may offer customer incentives to keep costs down.

“LEDs offer an exciting technology, and are part of a whole new way of looking at lighting. I expect we will be discovering new LED capabilities and benefits for years to come.”

 

 

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