Published Monday October 1, 2012:  Updated 1/11/2014


LEDs vs. CFLs

If you have not already upgraded from incandescent lighting to CFLs, you really should put the 1990's behind you and get with the times. CFLs will truly save you a lot of money in electricity over the life of the bulb. The technology is mature enough that you will get a quality product and each bulb (in most applications) will last half a decade or more.  

I originally switched all the lighting in the entire house to CFLs back in 1999.  Love them or hate them, because of the fantastic energy savings, I will faithfully use them, until something better comes along.  CFLs are inexpensive, reliable, safe, practical and the best alternative we have.   Until now!  

The day has come!  The next best thing is here and it's an LED.  

But why do they have to be so darn expensive?  As we wait for prices to come down, (and they surely will), I have found sources of inexpensive LED bulbs that work well in most lighting applications. 

Update 1/11/2014:  

Costco recently had a killer deal on LED bulbs.  They were $19.95 for a 3-pack with a $15 instant rebate.  You end up getting LED bulbs for $1.65 each. These aren't the crappy looking bulbs that cause interference either. These are high quality, dimmble bulbs that put out light that you would be hard pressed to know it was coming from an LED.  The last reason not to buy an LED bulb was cost.  Well, not any more.  

Now back to the article.....

LED vs. CFL

The actual power draw of compact fluorescent lights (CFLs) and LEDs is very similar.  So similar that one can hardly justify the costly upgrade from CFLs to LEDs.  An omni-directional 60 watt equivalent LED bulb and a CFL transmit almost the same amount of light with the LED only consuming 11 watts while the CFL is 13 watts.  By only saving 2 watts, the LED is a tough sell considering it costs upwards of 10x more than a CFL.  


If you are still only using incandescent bulbs, stop reading this, smack yourself on the forehead for wasting so much electricity/money over the last decade and go buy some more efficient bulbs immediately.  

LEDs are superior lighting (dimmable, tougher, contain no mercury, reach full brightness instantly, last upwards of 25 years) but the extra cost is still really hard for me to justify.  I can buy a lot of CFLs for the same price of 1 LED bulb at the hardware store and still reap almost as good of energy savings.  

But there are times when LEDs really do outshine a CFL in total life-cost and energy use.  That is in directional lighting applications.  

T-8 Tubes

In a fluorescent light tube, the light is radiated in all directions from the long tube.  Rarely does the lighting application require light in all directions.  It is the job of the light fixture to reflect and direct the light to where it needs to go, or else throw it away.  With imperfect reflectors used in light fixtures, most of the light is wasted.  

In an LED tube, there is an array of LEDs on one side along the length of the tube.  In this configuration, the LEDs only transmit light on one side of the tube.  Since most of the light generated is already pointing in the right direction, almost none of it is wasted.  This allows LED tube lights to only use ½ the power of a comparable T-8 fluorescent tube.  

In my measurements, a 48 inch, 16 watt LED T-8 tube actually puts out more light than a 48” 32 watt fluorescent tube.  They are the perfect solution for cold weather applications too since they reach full brightness regardless of temperature.  I found inexpensive LED tubes on E-bay for $12-20 a piece.  The only down side is (due to the cheapness of the power supply inside the tube), they take about 2 seconds before they even turn on.  After that, they come on instantly to full brightness. 

For what can seem like an eternity, you are left in the dark wondering if you turned on the correct light switch or not. I installed these LED tubes in my garage and have gotten into the habit of turning on the light switch before opening the door and walking out into the garage. That way, by the time I am about to take my first step down the stairs, the lights are already on at full brightness.  

You also have to modify the T-8 fixture by removing the electronic ballast and wire up each end of the fixture to feed the LED tube directly with 120VAC.  This isn't that difficult for home-owners to do themselves.  In the future, LED T-8 tube fixtures will cost less since they require no electronic/magnetic ballast.  

LED E-27 Bulbs

I recently found some short LED tubes on eBay with an Edison E-27 screw fitting.  They screw into a regular light fixture but only draw ½ the power of a comparable CFL.  So far, I can only find them from Chinese, Shenzhen based sellers.  They cost about $11-15 per bulb (much less than the $21-$47 for an LED bulb at the hardware store.  

I have tried the 5W, 7W and 8W tubes.  Basically the more LEDs in the array the more light you get out and the more power it consumes.  

They are perfect for ceiling fixtures in bedrooms, hallways and the like. Their color is slightly greenish compared to an incandescent or CFL but for a laundry-room, hall-way or anywhere else that isn't an art gallery, who cares.  

 Description CFL Equ. LED measured LED spec
 5W LED down-light  9 Watt 3.6 Watt 5 Watt 
 3.5W omni LED 9 Watt 3.8 Watt 3.5 Watt
 5W LED one-side 9 Watt
 4.3 Watt  5 Watt
 8W LED one-side 13 Watt 8.5 Watt  8 Watt
 7W LED down-light 9 Watt 6.8 Watt 7 Watt

For recessed lights, I am still looking for an affordable solution.  I tried some 7W LED spotlights with mixed results.  

They look great but the light is too focused into a spot to be used for bathing a room in light.  I put them down in my home-theater room and they look awesome.  They give the room a futuristic Starship Enterprise type of light, fit for an auditorium or movie theater.  

To date, my home's illumination is now 66% LEDs and 33% fluorescents. I also have a hand-full of necessary incandescent bulbs:  The oven bulb, microwave oven bulbs, sewing machine bulb and a candle-wax incense warmer bulb (there's no getting around that one). 


To compare apples to apples, I took some light-meter readings of various bulb configurations in a standard bedroom 2-bulb light fixture.  

 2 Bulbs in 1 fixture  
 Light Configuration  Relative Lux 
 No Light bulbs 0 Watt  1.0 
 LED 5W + 5W 17.3
 LED 5W + 8W 21.8
 LED 8W + 8W 23.8
 LED (bulb cover removed) 5W + 8W 25.0
 LED (bulb cover removed) 8W + 8W 27.0
 CFL 9W + 9W 24.0
 CFL 9W + 13W 27.5
 Incandescent 40W + 40W 21.7
 Incandescent 40W + 60W 27.3

Note:  Light-meter readings were taken 6-feet below and 6 feet to the side of the fixture.  The LED bulb cover reduces output by 3.2 lux. Removing this cover is acceptable in most lighting applications.  

Using the right combination of LED bulbs, the same luminosity can be attained while using less power than if you were using CFLs. 

 Type of Light bulb Power Price/bulb Lifespan Electric
 Costs/year
 LED 5W $12.00 25 years $1.46
 LED 8W $12.59 25 years $2.34
 CFL 9W $1.17 7 years $2.62
 CFL 13W $1.17 7 years $3.80
 Incandescent 40W $0.40 1 year $11.68
 Incandescent 60W $0.40 1 year $17.52

Electric costs assume using a light 8-hours a day and electricity costing $0.10/kW-hr.  For high-use light fixtures (or hard to reach fixtures) swapping to more efficient bulbs is a no-brainer.  

As you can see from the chart above, CFLs are slightly more expensive up front (over an incandescent bulb) but break even very quickly.  If you are still using incandescents, CFLs pay for themselves in 3 months.  LEDs pay for themselves in 1-2 years (over an incandescent bulb).  If you are using CFLs and are switching to LEDs the Chinese eBay ones pay for themselves in about 10 years.  Not great but if you are concerned about the mercury in CFLs (way over-hyped by the way) or don't like that CFLs can take a while to reach full brightness, they are justified.  

Blame my OCD but someday I want my home to be totally and completely illuminated by LEDs.  How cool would that be?  "Eat that, oven bulb."  

For a while now, hardware stores like Home Depot have been carrying recessed LED light bulbs.  They are pricey, costing about $33 each. Recently, Rocky Mountain power started offering a $20 rebate on each of these bulbs.  They end up only costing the consumer $13 each. By the way, the bulbs come with a halo too.  For new construction can-light fixtures, the halos alone cost $10 each.  This means for a new construction projects, you can in effect buy the bulb for only $3 each. This is a fabulous bargain for some very good quality LED recessed lights. 

I wish my power utility offered such a rebate.  

Epilogue:  

Someday in the far future we may look back over the long history of artificial illumination and see the 15-20 year reign of CFLs, laugh at how they were the 8-track / Betamax player of the artificial lighting industry and tell our grandchildren, "I remember using those curly-Q's."



LED Buyer Beware:  12/3/2012

Over the past 5-months, my TED whole-house power monitoring system has slowly become less reliable at reporting back readings of power consumption.  Something was interfering with its communication link across the electrical wiring in my house.  

Instead of having it located across the house, I tried moving the TED gateway right next to the MTUs (Measuring and Transmitting Units) inside the breaker box.  While the installation looks really fancy now, this change did exactly nothing to remedy the communication problem.  

Thanks to TED's awesome technical support, I was able to pinpoint the source of the interference.  It wasn't coming from any single breaker but was emanating from every one of the cheap, short, flat LED tubes that I owned.  I guess they were cheap for a reason.  This particular manufacture apparently left out a couple of key, 4-cent components from the switching supply inside the LED circuit.  

I find it very ironic that these very energy efficient, short LED tubes are interfering with the device that measures how energy efficient these LEDs are.   

Thanks to TED technical support and an X10 line filter installed between the TED and the rest of the house power, the interference problems are now history.  



Next Article:  Lawn Mowers Part I