LEDs: Ready for Liftoff? Presenter: Chris Calwell, Senior Fellow, Research & Policy with Ecova January 8, 2014
LEDs: Ready for Liftoff?
Presenter: Chris Calwell, Senior Fellow, Research & Policy with EcovaJanuary 8, 2014
Historical Approach to Utility Residential Lighting Programs
Reality:
CFLs are a good light source for most applications for some people, and for some applications for most people
CFLs are now cheaper than incandescents, so rebates may not be decisive in getting fence sitters to give them a try
They’re no longer the newest and most high tech kid on the block
Lesson:
People don’t buy light bulbs primarily to save energy; they buy them to provide light
Stated goal:
“a CFL in every socket”
Premise:
Cheap, long-lasting, highly efficient
If we just promote them long enough, eventually everybody will use them everywhere!
Early LEDs: Possibly Even Worse than Early CFLs!
But early LEDs did show promise that kept development going
Very long-lived
Light output, efficiency and cost all improved much faster than with CFLs
Inherently directional (made them a natural for reflector lamp applications where CFLs struggle)
CFLs and LEDs
Not bright enough
Bulky
Heavy
Ghastly color
Not dimmable
LEDs
Looked even weirder than early CFLs
Cost even more than early CFLs ($60-$80 vs. $20-$30)
Light dispersion not remotely omnidirectional
Growth in ENERGY STAR® Labeled LED Models
800 Lumen LEDs Steadily Moving Below $15 to Be Price Competitive with House Brand Bulbs and Multi-Packs
$14.98$23.99
Latest Price Trend Data Suggest 55% Reduction in Today’s LED Price/Lumen by 2017
Bright, Small, Efficient or Affordable: Hard to Optimize for Everything
Beware the “Snow Cones” - Special Optics Needed to Disperse LED Light Evenly
Meets ENERGY STAR Omnidirectional requirements
Source: GE Lighting. All Rights Reserved, © GE 2011
Non- Standard
Non-Standard LED A-Lamp
Omnidirectional LED A-Lamps
Voluntary California Quality LED Lamp Specification Aims to Improve Lamp Performance with a Focus on Six Attributes
Color Temperature
Color Consistency
Color Rendering
Index
Dimmability
Lifetime
Light Distribution
10
Do we want consumers to pay 54% more for 30% lower efficiency?
84 lm/W, CRI=80, $12.97
59 lm/W, CRI=93, $19.97
“Never Confuse What Can Be Counted with What Counts”
Tendency to simply increase the qualification numbers over time as more products receive ENERGY STAR label
Qualification process more selective, but doesn’t always lead to better outcomes if original procedures and metrics aren’t measuring the right things
Try this test at home or in your office:
Put two different LEDs with the same color temperature and light output into adjacent table lamps.
One with a CRI of about 82-84 (typical of most ENERGY STAR models today) and the other of more than 90.
Take a look at the light each casts on the wall and what shines through the shade. Hold your hand or a color photograph underneath each shade and study the colors carefully.
Does one look superior to the other? Can you even tell the difference?
Results
In informal lab tests, subjects couldn’t consistently tell the 80+ CRI lamps apart from the 90+ CRI lamps, or express preference correlating to a willingness to pay more for 90+ lamp
A perfect CRI score doesn’t tell how lamp will behave with wider range of colors, shades and subtle hues we encounter in homes
Color Temperature and Color Rendering Index capture only part of what it means for a bulb to provide attractive light
Why Performance Matters – The Same Reference Color Swatches Lit by Two Different ENERGY STAR LED Bulbs
Color Rendering Index (CRI) vs Color Quality Scale (CQS)
• Pastels, not saturated colors
• Simple average masks deviations
• Includes saturated colors
• RMS of 14 reflective samples
CRI
CQS
Source: US DOE Caliper Program
Asking the Question “What Makes an Ideal Bulb?” in a Different Way
No light bulb is perfect; each represents a mix of imperfect tradeoffs
However, we can assign weightings to the attributes we want in a lamp and see which ones consistently deliver the highest score.
In our LED reflector lamp work for IEE and TopTen USA, we found four key qualities were the hallmark of the best lamps:
Key advancement in research: Subjective aspects of lighting really matter to people who are buying a product that’s primary purpose is aesthetics
Higher measured efficiency than
required by ENERGY STAR
Lower than average lifetime cost of light and payback period (low incremental cost
relative to their expected lifetime energy savings)
Better than average performance in the
laboratory on a range of enhanced color, dimming, and technical attributes
Higher than average performance on human factors
testing – perceived uniformity and
natural appearance of the light itself
Preferred
The human eye is very good at distinguishing “good” light from “bad” light
Not Preferred
Beam patterns differ hugely from each other
Selecting the Top Ten LED Reflectors – the Winnowing Process
LED Downlight Data from IEE/TopTen Project
$20 $30 $40 $50 $60 $70 $80 $90 $100 $110 $1202
4
6
8
10
12
14
16
Previous TopTen PAR 30Average Previous PAR30Current PAR30Current TopTen PAR 30Average Current PAR30Previous TopTen PAR 38Average Previous PAR38Current PAR38
Purchase Price
Pay
back
Per
iod
(yea
rs)
PAR30 ENERGY STAR Average - $53.36 PAR38 ENERGY STAR Average $59.45
LED Downlight Data from IEE/TopTen Project
$20 $30 $40 $50 $60 $70 $80 $90 $100 $110 $1202
4
6
8
10
12
14
16
Previous TopTen PAR 30Average Previous PAR30Current PAR30Current TopTen PAR 30Average Current PAR30Previous TopTen PAR 38Average Previous PAR38Current PAR38
Purchase Price
Pay
back
Per
iod
(yea
rs)
PAR30 ENERGY STAR Average - $53.36 PAR38 ENERGY STAR Average $59.45
360391422453484515546577608639670701732763794825
Halogen (16.8 lm/W)
Spec
tral
Inte
nsit
y
99 CRI8 99 CRI14
2920K CCT
360401442483524565606647688729770811
LED - Early Generation (24.5 lm/W)77 CRI8
68 CRI14
7460K CCT
Sp
ectr
al I
nte
nsi
ty
360393426459492525558591624657690723756789822
LED - #1 on TopTen (62.9 lm/W)
Spec
tral
Inte
nsit
y82 CRI8 76 CRI14
3005K CCT
Wavelength (nm)360400440480520560600640680720760800
LED - High CRI(54.0 lm/W)
Spec
tral
Inte
nsit
y
93 CRI8 90 CRI14
2685K CCT
Wavelength (nm)
360389418447476505534563592621650679708737766795824
CFL (63.5 lm/W)
Wavelength (nm)
Spec
tral
Inte
nsit
y 81 CRI8 69 CRI14
2720K CCT
Pros and Cons of LEDs as the Preferred Efficient Residential Light Source
Pros
• Often 70-85 lm/W (relative to ENERGY STAR minimum of 40-50 lm/W) and heading higher
• Routinely dimmable
• Color can be easily customized
• Better optics solving the problem of uniform light distribution
• Semiconductor efficiency gains, reducing associated costs & size for heat sinks & drivers
• LEDs becoming less weird-looking
Cons
• LED lamp sizes and weights for >1600 lumens are still too high
• Prices for the brightest LEDs are also still prohibitive for most buyers - $30 to $60 per bulb
• Rate of improvement is so fast that waiting 6 months seems worth it – newer products will always be cheaper, brighter, smaller, and better
Aesthetically Critical Applications – Hard to Beat Incandescents in Certain Places
Red-dominated light is biologically important to us – it’s the light we associate with sunset and with flame. For most of human history, this has been our cue to go to sleep.
Blue-dominated light = mid-day sun = wake up.
Indoor lives increasingly dominated by fluorescent and LED sources directly (overhead lighting) or indirectly (backlit TVs, monitors, tablets and cell phones). These tend to be blue-dominated light sources – they start out by making blue or ultraviolet light, and then use phosphors to down-convert that to other colors of the spectrum.
Not surprising that we are experiencing more insomnia than ever as our reliance on blue light sources increases – they are telling our brains to wake up at precisely the time we want to go to sleep.
Our brains are also trained to associate dimmed light with more oranges and reds in color. CFLs and LEDs struggle to deliver that, though newest LED technologies can warm in color when dimmed.
2X incandescents have a role to play in efficient lighting portfolios.
Determining what bulbs to buy
Source: http://www.nrdc.org/energy/lightbulbs/files/lightbulbguide.pdf
Q & A Chris Calwell
970.259.6801 x301
1309 East 3rd Avenue, Suite 101
Durango, CO 81301
ecova.com
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