LEDs winning light race to save energy, the environment: report

Sep 05, 2012
New research from PNNL indicates light-emitting diode light bulbs, an example of which is shown here, are more environmentally friendly than compact fluorescent and incandescent lights. Credit: Pacific Northwest National Laboratory

Today's light-emitting diode light bulbs have a slight environmental edge over compact fluorescent lamps. And that gap is expected to grow significantly as technology and manufacturing methods improve in the next five years, according to a new report from the Department of Energy's Pacific Northwest National Laboratory and UK-based N14 Energy Limited.

"The light-emitting diode lamp is a rapidly evolving technology that, while already energy efficient, will become even more so in just a few short years," said Marc Ledbetter, who manages PNNL's testing, analysis and deployment efforts. "Our comprehensive analysis indicates in the near future will help people who use these lamps to keep shrinking their environmental footprints."

The report examines total , including the energy and natural resources needed to manufacture, transport, operate and dispose of . Fifteen different impacts were considered when evaluating environmental footprints, including the potential to increase global warming, use land formerly available to wildlife, generate waste and pollute water, soil and air. The report examines the complete of three kinds of light bulbs: light-emitting diodes, also called LEDs, compact fluorescents, or CFLs, and traditional .

Completed for the Solid-State Lighting Program of DOE's Office of Energy Efficiency & Renewable Energy, this is the first public report to examine the environmental impact of LED manufacturing in depth. Manufacturing processes contribute substantially to a light bulb's overall environmental impact, but companies generally keep manufacturing information private. The research team was able to gather manufacturing data with the help of industry consultants and some companies on the condition that the final report would not reveal individual company data.

Incandescents lose out

To do the analysis, the team chose specific bulbs that best represent what's most typical and widely available for each of the three types of lights they studied. They then used a database to calculate the resources needed to produce the various components of the three light bulbs. That analysis revealed both LEDs and CFLs are substantially more environmentally friendly then traditional incandescents, which consume far more electricity. For example, the specific incandescent light bulb the team studied consumes 60 watts of electricity, while the LED model they studied uses just 12.5 watts and the representative CFL only uses 15 watts to create about the same amount of light.

"By using more energy to create light, incandescent bulbs also use more of the natural resources needed to generate the electricity that powers them," Ledbetter said. "Regardless of whether consumers use LEDs or CFLs, this analysis shows we could reduce the environmental impact of lighting by three to 10 times if we choose more efficient bulbs instead of incandescents."

The energy consumed by lights when they're turned on makes up the majority of their environmental impact. But, with power consumption being similar between LEDs and CFLs when they are lit, the research team found the difference between those two bulbs' overall environmental performance is largely determined by the energy and resources needed to make them.

No aluminum advantage

CFLs were found to cause slightly more environmental harm than today's LED lamp in all but one of the 15 impact areas studied. The one standout area was generating hazardous waste that must be taken to a landfill. This is because LED lights include a component called a heat sink, a ribbed aluminum segment that is attached to the bottom of LED bulbs. Aluminum heat sinks absorb and later dissipate heat that's generated by the light bulb, preventing it from overheating. The process to mine, refine and process the aluminum in heat sinks is energy-intensive and creates several byproducts such as sulfuric acid that must be taken to a hazardous waste landfill.

But soon, research and development is expected to further improve LED efficiencies, which in turn will reduce the amount of heat they produce and the size of heat sink they require. The research team found that this, and other improvements in manufacturing processes and electronics, will lead LED bulbs to be even more environmentally friendly than CFLs within five years. The team expects the LED bulb of 2017 will have 50 percent less environmental impacts than today's LED lamps and 70 percent less impacts that those found in today's CFLs, which are not expected to change significantly in the near future.

Next, PNNL will examine the amount of hazardous materials that exist in LED, CFL and incandescent lights and whether those materials are present in levels that exceed federal and California waste disposal regulations.

This and other DOE reports on solid-state lighting are available online at www.ssl.energy.gov/tech_reports.html.

Explore further: Old timey car to replace NYC horse carriages shown

More information: Heather E. Dillon and Michael J. Scholand, "Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 2: LED Manufacturing and Performance," June 2012, apps1.eere.energy.gov/buildings/publications/pdfs/ssl/2012_led_lca-pt2.pdf

Related Stories

Alternative LED lighting combats energy crisis

Nov 17, 2011

Alternative lighting is emerging as a potent method to combat the energy crisis. Light-emitting diode (LED) lighting technologies could provide an innovative way to save energy and make wasteful lighting obsolete.

Rebates to cut price of $60 LED bulb

Apr 16, 2012

(AP) -- How much would you pay for an amazing, state-of-the-art light bulb? Shoppers will be asking themselves that very question at Home Depot and other outlets starting Sunday - Earth Day - when the bulb ...

Recommended for you

Obama launches measures to support solar energy in US

15 hours ago

The White House Thursday announced a series of measures aimed at increasing solar energy production in the United States, particularly by encouraging the installation of solar panels in public spaces.

Tailored approach key to cookstove uptake

15 hours ago

Worldwide, programs aiming to give safe, efficient cooking stoves to people in developing countries haven't had complete success—and local research has looked into why.

Wireless power transfer achieved at five-meter distance

15 hours ago

The way electronic devices receive their power has changed tremendously over the past few decades, from wired to non-wired. Users today enjoy all kinds of wireless electronic gadgets including cell phones, ...

User comments : 15

Adjust slider to filter visible comments by rank

Display comments: newest first

ChuckG
1 / 5 (1) Sep 05, 2012
The biggest problem that I see with these, aside from the high initial cost, is the questionable matter of retrofitting. The size of the heatsink on the base of these indicates that a considerable amount of heat is produced and needs to be dissipated during operation.

So what happens when I replace all of my BR38 flood lamps in IC-rated recessed ceiling "cans" with the new LED lamps? First of all, the LED lamps are being used "base up" and secondly, they're being used in closed, insulated enclosures--nowhere for the heat to go.

This type of fixture accounts for most of the permanent fixtures in my home. Replacing them with some other type would be prohibitively expensive.
fmfbrestel
5 / 5 (4) Sep 06, 2012
"The size of the heatsink on the base of these indicates that a considerable amount of heat is produced"

They still produce much less heat than an incandescent bulb despite the big heat sink. Regular bulbs dont care about heat much at all, whereas the LCD is very sensitive to heat - hence the big heat sink even though it produces very little heat in comparison.

"First of all, the LED lamps are being used "base up" and secondly, they're being used in closed, insulated enclosures--nowhere for the heat to go."

The heat dissipated to the air is still very little compared to a regular bulb, if there is almost any air circulation at all they will be fine. But you might have a worst case scenario in your home.

That said, in almost any existing fixture drop in replacements probably dont make a lot of sense unless you care more about the green environment than you do about green money. They are still pretty expensive, and might require modifications to existing fixtures.
kochevnik
4 / 5 (4) Sep 06, 2012
My 66rouble surface mounted LED bulbs produce almost no heat, and what little they do has nowhere to go but directly into the air. The unidirectional bulbs need to be mounted behind lenses, and could require heatsinks.
Sanescience
not rated yet Sep 06, 2012
Go to Lowe's and get an ESL bulb for your R30 home needs. I like them much better than either CFL or LED bulbs. They are made by Vu1 but last I looked Lowe's miscategorized them as "Warm White Halogen". They use electron stimulation and are "fast" on (about a second to reach full brightness) and fully dimmable with a compatible dimmer switch (avoid special made for CFL switches)and last for "10 years" which can't be confirmed obviously until 10 years go by.
VendicarD
5 / 5 (1) Sep 06, 2012
I have several LED bulbs that light my kitchen. 8 watt consumption, equivalent to 40 watts of light output. Two pads per bulb. Get warm to the touch, use diffusers (missing) to look like regular bulbs but now look like floods.

If they last 10 years, they will save me $336 in energy costs, and have already saved me $67 in energy costs.

Compared to CF lighting though they are about as energy efficient.

alfie_null
not rated yet Sep 06, 2012
It would be interesting to know what compromises are accepted by LED bulb manufacturers. Size/shape of heat sink, how acceptably close to the upper thermal limit (and what is considered to be an ambient environment - open air vs. enclosed in a fixture). Running components close to their limits (allowing use of less expensive components) vs. providing a long operating lifetime. Even less tangibles like the quality of the light (wide spectrum) vs. efficiency.
antialias_physorg
5 / 5 (1) Sep 06, 2012
For example, the specific incandescent light bulb the team studied consumes 60 watts of electricity, while the LED model they studied uses just 12.5 watts and the representative CFL only uses 15 watts to create about the same amount of light.

That seems a bit high for the LED. I just replaced 75 Watts of incadenscent bulbs with 4.5 Watts of LED and the light output is the same (if anything the LEDs do a better job at lighting the area)
DarkHorse66
not rated yet Sep 06, 2012
For example, the specific incandescent light bulb the team studied consumes 60 watts of electricity, while the LED model they studied uses just 12.5 watts and the representative CFL only uses 15 watts to create about the same amount of light.

That seems a bit high for the LED. I just replaced 75 Watts of incadenscent bulbs with 4.5 Watts of LED and the light output is the same (if anything the LEDs do a better job at lighting the area)

I had the same thought; their evaluations make it sound like there is virtually no difference between CFL and LED. If that were really true, then one would really need to question the perceived advantages of LED as being hype. Somehow, I don't think so. I have a 5 Watt CFL in a lamp that was rated at 40 Watt max wrt an incandescent. I would not have equated that anywhere near 4.5W LED. I also have an LED TV that is virtually cool to the touch (unlike plasma or LCD) and uses only a fraction of the power. Best Regards, DH66
Moebius
not rated yet Sep 06, 2012
My experience is that CFL's don't last much longer than a regular incand. bulb. I have bought and used up at least 50 and I seem to have had to change them out just as often as a regular bulb, at much greater expense. I've been buying LED's for the last year and they aren't that expensive, they definitely use much less power and you can be sure they will last for years.

As far as heat goes, yes they produce waste heat. But no wheres near as much as a regular bulb of any type. If an LED bulb is rated at 9 watts, that's how much power it will dissipate, about 1/7 the power (heat) of a 60 watt bulb.
antialias_physorg
not rated yet Sep 06, 2012
My experience is that CFL's don't last much longer than a regular incand.

In my experience that seems to depend on the manufacturer. The cheap ones burn out quickly, but until a year ago I still had 8 out of 9 in service from a 'high price' manufacturer that I bought about 15 years ago (and the one that burned out did so only the year before that. I now have all of those retired in favor of LED and other types of lighting)

Given the hassle of constantly replacing incandecent bulbs I gladly pay more for longer lasting ones. It's not really the energy savings that prompted the choice to switch over (though that is a nice bonus)
fmfbrestel
not rated yet Sep 06, 2012
My experience is that CFL's don't last much longer than a regular incand.


assuming your not using them with a dimmer switch or a 3-way lamp switch (both of which will destroy a CFL quite quick) you might have bad wiring. Even slight volatage changes can eat up a CFL quickly. LEDs are MUCH more tolerant than CFLs to this sort of thing, which is probably why your LED lights seem to last longer.
Eikka
not rated yet Sep 09, 2012
Given the hassle of constantly replacing incandecent bulbs


Yesterday I burned out my first halogen incandecent bulb. The box promised 2000 hours, but I had it for a year and a half. Hardly what I'd call constantly replacing one.

The beauty of the thing: perfect color rendering, instant on, brighter than any of the CFLs I have, even the 22 Watt ones, and it doesn't lose brightness or color over time, it's dimmable, doesn't mind voltage fluctuations or noise coming in through the powerlines, doesn't die of the heat inside a fixture, no electronic ballasts to break, costs a penny, saves me in heating 9 months out of a year...

The bad thing: these things are about to be banned as well when the efficiency standards are taken to the next level.
Eikka
not rated yet Sep 09, 2012
That seems a bit high for the LED. I just replaced 75 Watts of incadenscent bulbs with 4.5 Watts of LED and the light output is the same (if anything the LEDs do a better job at lighting the area)


Direct by-the-eye measurements are unreliable unless you had the lights running side by side. Switching between the two, you can have differences up to 30% in brightness before it becomes directly obvious.

The difference in spectrum is also key to percieved brightness. Put simply, in bluish light your pupil contracts more and contrast increases, so people feel that the light is brighter while there's actually less light coming into the eye than before and your color vision diminishes.

Typical LED light spectrum has a CRI of 75, whereas incandecent bulbs have CRI 100 by their very nature of being black body radiators. Standard CFLs are typically 85 and up. 100 is considered perfect, because it includes all of the visible spectrum.
Eikka
not rated yet Sep 09, 2012
I had the same thought; their evaluations make it sound like there is virtually no difference between CFL and LED.


There isn't, really. The best LED bulbs out there, like the Phillips L-prize achieve luminous efficacies of around 94 lm/W whereas fluorescent lights routinely go past 100 lm/W. Not the cheapest ones of course, but you do have to pay $50 for a LED bulb that even compares. None of the eBay crud actually makes it.

If that were really true, then one would really need to question the perceived advantages of LED as being hype.


It is hype. LEDs are even more sensitive to heat than CFLs, and they have similiar electronic ballasts that break from voltage fluctuations, and they produce worse light output, and they are much more expensive. The only thing where they truly stand out is the fact that it's possible to make a LED bulb that actually lasts 50,000 hours if you drive the chips at 1/3 their rated current and brightness, and you affix it to a big heatsink.
antialias_physorg
not rated yet Sep 09, 2012
Direct by-the-eye measurements are unreliable unless you had the lights running side by side.

Direct eye measurement is what counts, here - because in my home I decide what I feel lights stuff better and what doesn't - no matter what the numbers say. Lighting is dependent not only on the characteristics of the product, but also on the eyesight characteristics of the one using them.

CFLs are the same price over herethan LEDs (as figured per lightoutput on the box). Thy have the same lifetimes, but LEDs have a quarter to 1/6th of the energy needs.
All else being equal, I'll go with LEDs any day.

More news stories

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...