Cree 60w warm white LED review and comparision

Background

We've been using CFL bulbs for a number of years.  The good new about CFLs is that they use less electricity than incandescent light bulbs - typically about 1/4 as much.  Their pricing is less than LEDs today, but still more than incandescents.  But they have a number of disadvantages, too:

• The quality varies greatly from brand to brand.  The off-brands may be cheaper, but typically exhibit most of the bad points listed below.  And even the top-tier brands exhibit some.
• They're slow to reach full brightness - often taking a minute to more than 10 minutes(!) to get close to full brightness.
• They get dimmer with age.  The cheap brands in particular seem to lose about 1/3 of their brightness after a couple of years.
• Their lifetime is significantly shortened by repeated on/off cycles.  Yes, they may last 25,000 hours if left on all the time, but in a room where they're turned on & off a lot (a bathroom, for example), they might last half as long, if that.
• They contain mercury, which makes them a hazardous material and thus they require special procedures for disposal.
• Early CFLs were very "cool" - they had a color temperature in 5,000° Kelvin range, so their light had a distinctive bluish cast, unlike incandescents, which are typically much "warmer" (3,000° Kelvin or so) and cast a more yellowish light.  Current CFLs are available with a "warmer" tone to them, but you have to look for them.
• Early CFLs were not usable in dimmers.  In fact, they would typically be destroyed by such use. There are special "dimmable" CFLs available now, but they're typically more expensive than the non-dimmable units and are often not "full range dimmable", meaning that if you try to dim them all the way, they'll typically turn off at around 40% brightness.

So with all of that in mind, I've been looking at alternatives.  LEDs are a better technology, IMHO - hazardous material-free, even more energy conservative than CFLs and most are dimmable.  But they've typically been pretty expensive ($30-$40 for 60 watt equivalents, $50+ for 100 watt equivalents).  Because they typically need heatsinks to cool their electronics, they've often been designed in unusual shapes, many of which are either aesthetically displeasing, or won't fit in many places where A-type incandescents do - table lamps with harps or lampshades which clip onto the bulb, for example.  Early CFLs had similar issues, but most are now packaged to be closer in size to traditional A bulbs.

Cree 60 watt equivalent LED

Cree just introduced a line of inexpensive 40- and 60-watt equivalent LED A-style light light bulbs about a month ago.  What makes them relatively unique in the market is their price.  Home Depot is selling them for $9.97 for the 40-watt and $12.97 for the 60-watt.  They've been getting good reviews elsewhere on the 'net, so I rode down to my local Home Depot and picked one up to try.  I pulled a couple of CFLs out of lamps (one 60-watt equivalent, one 100-watt equivalent) as well as a 60-watt incandescent to serve as the "standard candle".

The bulbs used in this comparison - L-R:
GE 26w dimmable CFL, Generic 20w CFL,
Cree 9.5w LED, GE Long Life 60w incandescent

Statistical comparison

Lighting technology comparison

Type of bulb	Equivalent Incandescent watts	Measured Watts	Measured VA	Measured Power Factor
GE Long Life White 60 watt incandescent	60	57	57	.99
GE 26w Dimmable CFL	100	25	36	.67
Generic 20w CFL	60	20	40	.50
Cree 9.5w Dimmable LED	60	8	10	.74

As you can see, the energy consumption of the LED is less than half of either CFL and only 1/7 of the incandescent!  You can also see by the Power Factor rating that the generic CFL is of inferior quality to the brand-name unit.  It's basically less efficient.

Now on to what you want to see - the pictures.  What about light quality?  Color?  Intensity?  All of the shots below were taken with a Canon EOS T3i set to manual exposure, 1/125 at F4.5 to ensure that they are as comparable as possible.

Pictures

Floor lamp

GE Long Life White 60 watt incandescent

GE 26 watt dimmable CFL
(100 watt equivalent)

Cree 9.5 watt dimmable LED
(60 watt equivalent)

You can probably see that the 100-watt equivalent CFL is somewhat brighter than either 60-watt lamp, but the color of the LED more closely matches that of the incandescent.  All were roughly similar in color temp - I'd call it "warm white", probably in the 2,800°-3,200° K range.

Table lamp

Cree 9.5 watt dimmable LED
(60 watt equivalent)

Generic 20 watt CFL
(60 watt equivalent)

In a table lamp (sans shade), the light color and intensity is very close between the two 60-watt equivalent energy saving lights.  But I found it easier to replace the harp with the LED bulb due to its more conventional shape.

LED light dispersal

By stopping down the camera lens, I was able to get a better idea of the light dispersal characteristics of the Cree LED.  As you can see, there's considerably less output from the top (and bottom), making it a less-suitable candidate for spot or downlight applications.  It's ideal for table lamps, where most of the light should come out of the side of the bulb.  

Light dispersal of Cree LED
Note band of light in center, dropoff at top and bottom

Dimmability

I tested the Cree LED against the GE dimmable CFL in a wall sconce controlled by a Lutron wall dimmer switch.  The CFL dimmed about 40% before going completely dark when the dimmer slider was at about the 30% mark.  The LED kept getting dimmer throughout the range of the dimmer slider.  In addition, with the dimmer at its lowest level, I was able to turn off the LED and then turn it back on, while the CFL stayed dark when the switch was toggled.

Summary

I've only had the LED for a couple of hours now - not really enough to make a good comparison, but the combination of energy efficiency, dimmability, relatively low cost and lack of hazardous materials make the Cree seem like a winner.  I'll probably pick up a six-pack on my next run to Home Depot.

One More Thing...

I have nothing to do with any company mentioned other than as an interested consumer.  And in that vein, there's another technology on the horizon that may also prove a lighting game-changer.  It's called ESL (Electron-Stimulated LuminescenceTM) and the company closest to commercialization is VU1 with their 65-watt floodlight replacement.  They hope to have product in the marketplace later this year.  I have an application, so I'll likely pick up one as soon as I can.  If you know of other good lighting products, feel free to leave a comment!

It's almost Christmas: LED vs traditional C9 lights

I've always been traditional with my outdoor Christmas lighting - only the good ol' C9 incandescent light strings are good enough to put on my house.  I've had a number of 25-bulb strings for about 25 years, but since adding solar to our roof in 2010, I've been aware of just how much electricity my holiday lighting is using.  The miniature lights are much better than C9s on a one-for-one basis, but most mini-light strings put their bulbs much closer together than the 12" spacing of my C9 strings, so they're probably somewhat better, but maybe not so much - not enough for me to switch.

The other thing that's always frustrated me about C9 lights are their fragility.  It seems like no matter how gently I put up and take down the strings, every year I have to go through the ritual of finding and replacing the burned out bulbs before stringing them on the house.  And invariably, the one bulb at the apex of the roof burns out 2 nights after I put it up.  And with bulbs going for at least 25¢ apiece, I figure I spend at least $2-$3 a year in bulbs.  There's gotta be a better solution...

Philips C9 faceted Christmas lights

Enter the LED C9 strings.  I bought 4 25-bulb strings of Philips multicolor LED faceted C9 light strings  at the local Target to compare to my incandescent C9 strings.  Although I had a slight preference for the smooth bulbs, I didn't care for the light dispersal as much - the faceted ones seemed to illuminate the entire "bulb" better.

First test:  Energy efficiency

C9 incandescents - about 160 watts

Using my trusty Kill-A-Watt energy meter, I plugged in an incandescent C9 string.  Just about 160 watts (I had a few flashers in the string, so the wattage varied about 10 watts or so as bulbs flashed on & off).  C9s are rated at 7 watts apiece, so a full 25-light string of standard bulbs should be about 175 watts.

C9 LEDs - just 2(!) watts

Next up was an LED strand.  I plugged it in and looked: 2 watts!  The entire string was using less than one-third of the electricity that one C9 bulb consumed!

Second test:  Aesthetics (how they look)

I know what you're thinking - these things must be ridiculously dim.  Truth be told, they are significantly dimmer than C9 incandescents.  But the only way to truly judge is on the house, in the dark, side-by-side - so that's exactly what I did.  The photo below shows a string of incandescent C9s on the main house (starting to the left of the garage door) and a string of LED C9s on the right (over the garage door).  The difference is obvious - you could probably read a book by the incandescents, while the LEDs serve to add just a hint of color to the roofline.

Incandescent C9s on the left, LED C9s on the right
(click for an enlarged image)

As much of a traditionalist as I am, I was surprised to find that I actually prefer the LED lights.  They don't light up the walls of the house, so they don't get washed out by their own brightness.  Couple that with the energy efficiency and lack of annual maintenance, and we have a winner, at least in my book.

Third test: economics (are they worth it?)

So - aesthetics aside, is it worth it economically to use LED C9s instead of incandescents?

If you're buying new, I think that LEDs are a no-brainer unless you really have an issue with their brightness.  They cost about double upfront ($12 vs $6 per 25-light string), but factor in the need to replace bulbs and the electricity difference and the payback is probably 1-3 years.

In my case, I was trying to determine the payback period considering that I already had the incandescent strings.  Here's my thought process and calculations - you'll have to do the math for your scenario and see what works.

I have 4 strings of incandescents.  4 strings of LEDs runs $48.00 + tax - lets round to $50 (I bought mine on sale for $11 each).  I typically have my lights on between Thanksgiving and Christmas, about 4 hours each night.  My wintertime electricity rate is about 12¢ per kWh, so let's run the numbers:

Cost per year for incandescents:

• Replacement bulbs:  $2.00
• Electricity: 160 watts / string x 4 strings x 4 hours / night x 30 nights / year = 76,800 watts (or 76.8 kWh) x 12¢ / kWh = $9.21

So I'm paying about $11.21 per year for my current display.

Cost per year for LEDs:

• Replacement bulbs: $0.00 (each sting included 2 replacement LEDs, but I can't imagine them going bad more than 1-2 per decade - time will tell).
• Electricity: 2 watts / string x 4 strings x 4 hours / night x 30 nights / year = 960 watts (or 0.96 kWh) x 12¢ / kWh = $0.11

So I'll be paying 11¢ per year for the LEDs.

And the Winner is: LEDs

Factor in the upfront cost of $50.00 for the LED strings and you'll see that the breakeven point is between 4 and 5 years for my scenario.  Yours might be different, but I think that in most cases, there's still an excellent case to be made for LED outdoor Christmas lights.

Merry Christmas to you and yours!

Update 11/23/12:  X-10 modules and LED lights don't mix (well)

X-10 modules

I use the old BSR X-10 appliance modules to turn my outdoor (and indoor) Christmas lights on & off remotely - I've done it for years.  The switch to LED lighting brought out a problem - the X-10 modules "leak" a tiny bit of electricity when switched "off".  Appliances and incandescent lighting are unaffected by this, but it's enough to cause LED lights to not turn off completely.

Using the oracle of Google, one can find a number of solutions to this issue - most involving putting a small load on the switched side of the X10 module with the LED lighting - something like an incandescent night light, a plug-in air freshener or even a "wall wart" transformer.  There are also mentions of more sophisticated solutions involving opening up the X10 module and adding or removing resistors.

I opted for the low-tech approach of plugging in a wall wart on the switched side of my X10 modules.  Even without being plugged into anything the wall wart transformer draws enough energy to keep the LED string dark.  It's kludgy, but it works.