leds: ready for liftoff?

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

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

[email protected]

970.259.6801 x301

1309 East 3rd Avenue, Suite 101

Durango, CO 81301

ecova.com

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leds: ready for liftoff?

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