making cents of leds

Making Cents of LEDsHow (and Why) to Choose and

Use Emerging Lighting Technologies

Your environmental voice since 1970 www.cleanwisconsin.org | Twitter: @cleanwisconsin

9th Annual Green Energy Summit and Exposition

Breakout Session 1-1

Tyson CookStaff Scientist, Clean Wisconsin

Outline

What is Sustainability?

• Brundtland Report (1987): “meets the needs of the present without compromising the ability of future generations to meet their own needs”

• Three pillars: social, environmental, economic

• For businesses: “Triple Bottom Line”– People, Planet, Profit

• Live well, leave well

How is energy efficiency sustainable?

• People– Health, other quality of life impacts from air,

water pollution, etc.

• Planet– Environmental impacts from air, water

pollution, water use, resource extraction, etc.

• Profit– U.S. commercial sector spending on energy

in 2009: $170,100,000,000 ($170.1 billion )

Why LEDs/ Why now?

• Lighting is often the cheapest and easiest efficiency upgrade

• LEDs are the most efficient lights(in many applications)

• Prices are now competitive over lifespan

(in many applications)

What are LEDs?

• LED stands for “Light Emitting Diode”

• “Solid State” technology– Like a solar panel in reverse

• Complete LED light = driver, diode, phosphor, lens, heat sink, wiring–May be replacement bulb, or complete

“luminaire”

How are LEDs different?

• There’s no filament, no gas, etc. – they’re a different technology (solid state)

• They are directional• They can be long-lived• They don’t (usually) burn out – they

gradually dim• There are tons of options

How are LEDs sustainable?• Compared to other lights, LEDs can:

– Work Better• More options for improved light quality

– Use Less• 6x as efficient as 60w bulb, 1.5x as efficient as CFL …and improving

– Waste Less• Lasts 25x as long as 60w, 2.5x as long as CFL … and no mercury

– Cost Less• Energy + maintenance savings over life > initial premium

• Seems to fit the bill

Pros and Cons of LEDs

Pros• Efficient• Long-lasting• Non-hazardous• Produce less heat• Directional• Lots of options

Cons• Expensive• Sensitive to heat• Directional• Lots of options

Back-of-the-Envelope Comparison: Parking Lot

Lights

Cost, use data from: M Myer, R Goettel, “Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting at T.J.Maxx in Manchester, NH, Phase I.” Pacific Northwest National Laboratory , June 2010

Emissions, mercury data from: US EIA, WDNR, NEWMOA

HPS (w/MH) PMH Bi-Level LED LED Savings

First-Year Cost $429.82 $1,502.08 $2,012.00 ($1,582.18)10-Year Savings -- ($700) $450 $450

10-Year Electricity Use (kWh) 21,481 16,118 6,274 15,207

CO2 Emissions (pounds) 34,778 26,096 10,158 24,620

SO2 Emissions (pounds) 107.4 80.6 31.4 76.0

NOx Emissions (pounds) 36.5 27.4 10.7 25.9Mercury Emissions (mg) 269.7 202.4 78.8 191.0Water Use (gallons) 322,216 + 10,741 241,776 + 8,059 94,110 + 3,137 228,106 + 7,604

Total Bulbs Needed 2 3 1 1Mercury in Bulbs (mg) 60 678 0 60

Back-of-the-Envelope Comparison: General (A)

Lamps

Assumptions: light on 3,000 hours per year, $0.10 per kWh, $1.67 in labor to replace a bulb, 6% discount rateEmissions, mercury data from: US EIA, WDNR, NEWMOA

Incandescent Dimmable CFL “L-Prize” LED LED Savings

First-Year Cost $22.66 $12.83 $54.42 ($31.76)10-Year Savings -- $134 $113 $113

10-Year Electricity Use (kWh) 1,800 390 300 1,500

CO2 Emissions (pounds) 2,914 631 486 2,428

SO2 Emissions (pounds) 9 1.95 1.5 7.5

NOx Emissions (pounds) 3 0.7 0.5 2.6Mercury Emissions (mg) 22.6 4.9 3.8 18.8Water Use (gallons) 27,000 + 900 5,850 + 195 4,500 + 150 22,500 + 750

Total Bulbs Needed 30 3 1 29Mercury in Bulbs (mg) 0 1.3 0 0

What to look for when choosing LEDs

C olorE fficacyL ifeL imitationsS upport

Color E L L S

• Correlated Color Temperature (CCT)What tint is the light?

–Rated in Kelvin, from <2,700 (reddish) to >6,000 (blueish)–60w bulb ~2,700k, “Warm white” ~3,000k–Mostly a matter of preference, but make sure they match!

• Color Rendering Index (CRI)How vibrant are colors under the light?

–Average reflection from a defined 8 color palette (R1 – R8)–Ranges from 0-100

• (60w bulb = 100, normal streetlight <25, fluorescent 50-80)• LEDs ~50-95

–NOTE: Standard CRI doesn’t include bright red (R9)• One attempt at a better measure is the “Color Quality Scale”

C Efficacy L L S

• Lumens per Watt (LPW)How much light do you get for how much power?

–Lamp efficacy• What’s the LPW out of the LED itself?

–Luminaire efficacy• What’s the LPW of the whole light fixture?• Especially important in directional applications (like down-lights

or outdoor lights; a lot of the light from traditional sources can get lost)

C E Life L S

• Expected Useful Life (EUL)How long until you have to replace the light?

–LEDs don’t burn out, just fade away• (unless the wiring or driver fails)

–So when do you replace them?• “L70” = how long (in hours) until the light is only

70% as bright as it started• Ranges from <10,000 (~1 year without turning

off) to >50,000 (>5 constant years)

C E L Limitations S

• Dimming– Can they be turned down? How far?

• Distribution– What does the pattern of light look like?

• Flicker– Especially when dimmed

• Noise– Especially when dimmed

C E L L Support

• DOE LightingFacts Information– Check to make sure they’ve had

independent testing– Look for LightingFacts label, or check:

www.lightingfacts.com

• Warranty– “Our lights will last you 10 years - and we

back that up, with a 1-year limited warranty!”

Current LED marketplace: Outdoor

Current LED marketplace: Directional

Current LED marketplace: General

Making it easy(?):Where to use LEDs

• Directional Applications– Down lights– Refrigerated case lights– Task lights– Track/ spot lights– Under cabinet lights

• Outdoor Applications– Streetlights– Canopy lights– Garage/ Parking lights

• Heat-Sensitive Applications– Lighting artwork– Lighting perishables

• NOT to Replace Linear Fluorescent Lighting (yet)– For now, stick with high-efficiency fluorescents, unless durability and

maintenance costs are key

Making it easy(?):How to choose LEDs

• Compare to your needs

• Compare your options– LED vs. conventional lights– LED vs. fluorescent– LED vs. LED

• Compare whole-life costs, including energy, maintenance, and replacement

• Try them out!

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Back-of-the-Envelope Cost Comparison60 Watt Incandescent Philips EnduraLED

Bulb

Assumptions: light on 9.5 hours per day (2,500 hr/ yr), $0.10 per kWh, $1.67 in labor to replace a bulb, 6% discount rate

First-Year Cost: $22Bulbs needed over 10 years: 25

Annual Energy Cost: $15Annual Replacement Cost: $5.83

10-Year Total Cost (NPV):$161.85

First-Year Cost: $33.62Bulbs needed over 10 years: 1

Annual Energy Cost: $3 Annualized Replacement Cost: $3.06

10-Year Total Cost (NPV): $50.9710-year Savings vs. 60w (NPV): $110.88