Could LED lights be superior to CFL?

by Ginosar  

Twenty years ago I irritated a member of the Sacramento Municipal Utility Board, SMUD, when I answered media questions about Compact Fluorescent Lamps CFL, honestly and told them they have serious problems that must be solved before CFL could have wide public acceptance. He told them that all is well with CFL. He was wrong then and his type of approach -cover the negatives instead of correcting them - does not work.


Introduction: Standard light bulbs use a lot of electricity; we can save three quarter of the electricity by replacing them by compact fluorescent lamps, CFL. CFL did not capture much of the market because of their many limitations. Could the new light emitting diodes, LED, lamps achieve a much wider penetration, even with laws dictating higher efficiency light? I doubt it if we handle LED in the same poor way we did CFL.



Lighting uses considerable amount of our home electricity because we are using incandescent bulbs. The majority of these bulbs' electricity goes into heat, and less than 5% into light. Not only that, during the summer the heat portion warms the house interior, putting additional load on air conditioning. Since a typical electric power plant is just 33% efficient, reducing electrical waste saves three times as much in energy input [coal, gas] in our electrical systems, resulting in three times reduction in greenhouse gas GHG emissions.

Replacing one standard bulb by compact fluorescent lamp- CFL cut electricity to just one quarter, thus cutting our primary energy use, and GHG, by 12 times!!


Some of the reasons for considerable increase in home electricity use in the last two decades are bigger houses, using lights for decoration, and increasing use of indirect lighting that can demand up to ten times the light of direct lighting.

For the last quarter of a century the drive to reduce electrical demand by replacing standard light bulbs with compact fluorescent lamps, CFL, that are typically four times more light efficient, did not make much impact. There are some laws now that would dictate selling of only higher efficiency lights to increase markedly the use of CFL and LED, but we may have the same problems again.


Here are some of the limitations that reduce the use of CFL:

Very poor quality. Originally US and Europeans made CFL had long life and more steady output, but as the Chinese entered the market the quality went down drastically. Because of that and more, the public discarded its initial enthusiasm of CFL when experience showed:

1. Considerably Shorter life than specified.

2. Quick death when CFL are enclosed.

3. Shorter life when the lighting element is placed downward since heat goes up and heats the electronic parts.

4. Slow start

5. Very poor quality control: Noisy CFL and half-light CFL are common, while never with standard bulbs.

6. Light color is not always comparable to standard light bulbs.

7. Use of mercury.

8. Can't adjust light intensity [new adjustable CFL are costly]


There are technical solutions to some of these problems, but many of the problems are due to poor quality control. It is hard to achieve sustained improvements when the seal of approval is given to the CFL by utilities, by mass marketing and by inadequate seal of approvals. In short, little attention is paid to the problems. See my letter in the next posting to my local utility of two years ago. I have not witness any improvements in CFL in recent times.


I am bringing this subject up because some are advocating bypassing the "CFL age" by Light Emitting Diodes- LED.

LED have the advantage of simplicity and very long life, possibly as much as 50,000 hours [15 years] vs., some 8,000 to 10,000 hours for CFL. It is promising but...

The problems are the very high cost of LED and the need for even tighter quality control than on CFL.


The main attraction of LED is their very low electricity consumption, a potential for several times better than CFL. However, the light output of LED vs. energy input, that is, its light efficiency, can vary by ten to one. The manufacturing processes, the material used, the quality control can all contribute to a very low energy efficiency that the buyer is unaware off. Most buyers will seek low cost units, but they would not know the real efficiency of the LED. And the normal tendency to cut corners to increase profits is likely to kill this promising technology too.

Also heat is still a problem, the cooling aspects and the electronic components used could be damaged by heat, depending on positioning, and ease of natural cooling around the LED.


In Summary:

The same problems that have cut down the market penetration of CFL - poor design and poor quality control, can also kill the market potential of LED, and even more so. It is easy and cheap to produce and sell LED that would have low efficiency and shorter life expectancy than possibly CFL. And since the initial cost of LED is expected to be much higher than CFL for the near future, the cost of poor quality and low efficiency could again kill this promising market.


My Suggestion- we could now improve the penetration of CFL, which is already here, by demanding government seal of approval for better design and high quality as the price of selling CFL.

 

 

Reader Comment:

This is excellent. You have done a marvelous job. I like the way you wrote this up.

 

I had the same sad experience over the past two years. I didn't read anything about this until now, but I found out from experience what you have described here. A few years ago I decided to do what I could to install CFLs in fixtures that we use for more than four hours a day. At first, I thought I might be saving as much as ten percent of the electricity we use.  Soon, I experienced every single one of the eight limitations you outlined in your paper below.  The short life of these CFLs is doubly compounded by the mercury problem, as it is still a real hassle to properly dispose of these spent lamps, and since I won't toss them into the landfill, I let them pile up in my house.

 

A few years ago at Cal, I met up with a top specialist in Conservation and I mentioned my concerns about the billions of CFLs that might be landfilled over the coming years.   He told me how proud he was that Wal-Mart had agreed to sell millions of them and tried to calm me about mercury by telling me that Cal EPA would have the mercury problem well in hand.  I knew better.  Now three years later the problem is still real.

 

The shortened life of these CFLs due to enclosure and upside down orientation is very real, as the lamps I installed in my bathroom inside the glass globes have only lasted about a year or so, so, maybe 700 to 1000 hours. I didn't take the time to be systematic about which CFLs did what, but this has been my basic experience. So, it's just one more broken promise that the environmentally and cost-conscious consumer has to deal with. Given all these drawbacks, it's impossible to know if one is saving any money, but for sure, it's a big hassle.

 

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