How green are Compact Fluorescent Lights (CFLs)?

April 27th, 2009 | Posted in Energy Efficiency - lighting, Energy Efficiency - news
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Back on this  subject…

fluorescent lightSome countries and states like Australia, California, and the European Union plan in the near future to ban incandescent light bulbs, to the benefit of  Compact Fluorescent Lights, Lamps (CFLs).
There are two main advantages given by (CFLs) : …

  • High light efficiency (quantity of light produced per watt of electricity), multiplied by a factor of 3 to 4 compared to incandescent lamps,
  • Lifetime multiplied by a factor of 10.

Worldwide, this represents a huge quantity of electricity saving and CO2 emission!

But is it as green as it seems after all?

Some aspects related to this technology are less idyllic and should be considered in the global assessment:

  • The main issue is the presence of mercury in the fluorescent tube, as well as some toxic materials such as lead in the necessary electronic circuit. That is why collecting and recycling of spent CFLs is absolutely mandatory in order to avoid spilling of the environment.
  • CFLs are much more complex and heavier than incandescent lamps. This results in a higher need for energy for manufacturing and delivery. Recycling is also requesting energy, so that, at the end, this partly counterbalances the advantage of lower energy consumption.
  • In cold countries, the heat produced by incandescent lamps participates in the global heating of the homes. Reducing the heat produced by lamps must simply be compensated by more energy produced by the heating system.
  • The current absorbed by the electronic circuit is far from a pure sinusoid. This means that a higher current is necessary for a given power compared to a purely resistive circuit such as an incandescent lamp. The current distortion ( …) may be responsible for additional losses and disturbances in the supply network.
  • And last aspect: as CFLs do not operate instantaneously and need a few minutes before achieving full lighting efficiency, people are inclined to let them turned on, even if it is not necessary.

Are Fluorescent bulbs (CFLs) to be the only available anyway everywhere in the future?

If yes, you’ll have to accept some drawbacks:

  • Higher replacement cost, particularly worrying for bulbs turned-on infrequently,
  • CFLs are sensitive to extreme temperatures, making them unsuitable for outdoor usage,
  • Frequent turning on and off significantly reduces the lifetime, so CFLs are not appropriate in such conditions,
  • No possibility of dimming,
  • No possibility of directional lighting.

That is the price to pay for a .
Jacques Schonek

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Comment(s) to “How green are Compact Fluorescent Lights (CFLs)?”

  1. Folke Asell says:

    How green are CFL’s (Compact Flouresent Light)
    I totaly agree with Jacques Schonek comments.
    There is too little information given about the reality of the CFL’s. The industry have only been talking about the reduction of energy consumption but have kept all the negative environmental hazards in the dark.
    Some countries like i.e. Sweden have very strict rules on how to handle CFL’s when broken or when disposed of in order to limit the spread of the very toxic mercury in the landfills. When these issues become known to the public and mandatory handling rules are in place it will be very clear that CFL’s is not the solution for environmental friendly lighting.

    The only environmentally friendly evolution on lighting to day seems to be LED lighting which is extremely efficient even though still some what costlier that the toxic CFL’s. The much longer life time of LED’s (+50.000h) compensate though to a great extent the price difference and the rapid development within the sector is continuously reducing price.
    When classifying products energy efficiency it should also information about toxicity.
    Folke Asell

    • I wholly agree that LED is best option available in the market.When big organisation promotes CFLs as better than incadescent is basically a marketing gimmick.They didnt show that esp that CFLs contain mercury vapour and also can indirectly contribute to migraine due to exposure.
      Currently there are concerted moves in EU contries to ban incadescent and most likely Aust and NZ will follow suit.
      Even for current 60W household incadescent light bulb is inefficient but the promoted “better off” CFLs contains mercury vapour.So neither is really better off.However LED even 3.3W can generate same output as the two previous lights but with longer life and less carbon.
      LED is the technology that will revolutionise the Energy Efficiency on lightings globally and relevant info should be disseminated esp to third world countries before they run the risk of being dumped with banned incadescent and or CFLs thats bannd from developed countries.
      Pere,Redcarbon,Fiji Islands

      • I completely believe the fact that LED is best choice available that you can buy.When big enterprise stimulates CFLs as better than incadescent is generally a marketing trick.They did not display that esp that CFLs contain mercury fumes and also can in a roundabout way promote headaches due to visibility.
        Currently there are serious goes in EU contries to ban incadescent and most likely Aust and NZ will adhere to.

  2. CFL’s are a great way to save a little on your energy bill. CFL’s are slower to brighten up than incandescents. They cost a little more initially, but the savings should more than pay for that. Bulb life is much greater than the incandescent bulb, but the compact has dangerous mercury in it.

    In my article CFL’s – A New Twist In Light Bulbs, I discuss the advantages and disadvantages of CFL bulbs.

  3. Daniel12 says:

    Thank you Jacques for this accurate and good article ; I have a question linked to health problem : are CFLs dangerous for human ? we know that it generates relatively high magnetic field and this sounds not so good when close to human body. Do you have any position or technical data on this aspect ?

    • Jacques Schonek says:

      This question is a subject of intense debate, and I have no ability to answer. All I can say is that CFLs are using the same type of circuits as electronic ballasts for standard fluorescent tubes, which are used for a long time without controversy.

  4. Rumora says:

    Be so kind to give me an answer to my scruple. How the CLS have infuence on human eyes? We know as well that “white light”, naturaly sun light and also light from bulbs have complete spectar of colours, the CFLs does not have that kind of light, that is the reason that we fatigue our eyes more than in case we use bulbs.
    Can you give me your opinion about that. I think that this fact is very important?
    Best regards!

  5. Jacques Schonek says:

    Indeed, CFLs like all fluorescent tubes do not produce a warm and colourful light as incandescent bulbs. But as far as I know, there is no acknowledged consequence on the health of our eyes. This is only a question of comfort.
    Some old technology tubes may produce flicker (rapid fluctuation of light intensity), but this is totally solved with electronic ballasts included in CFLs or associated with recent technology tubes.

  6. Rob Murray says:


    I have sucessfully specified 2700K fluorescent lamps and CFL’s for clients that required an “incandescent look”, mostly in nursing homes here in the States. Interestingly enough you can also specify 2700K for LED cove lighting applications!

    Timothy Thiele:

    You can now get “instant on” CFL lamps that require no warm up. Phillips Amalgram (SP?) is one brand that comes to mind. My wife just bought some for our bathroom and they work great.

  7. kelash kumar maheshwari says:

    Best information.

  8. James says:

    Energy efficient light bulbs are the easiest first step consumers and businesses can take towards reducing their energy consumption. Products have gotten light years better in the past few years and, in my eyes, indisputably better for 99% of applications. Both CFL and LED light bulbs run much cooler than incandescent bulbs, use energy much more efficiently, and do offer saving on your electricity bill. I am a vendor of energy efficient bulbs, so perhaps I am a bit biased, but I don’t know why everyone doesn’t switch today.

  9. John B says:

    I believe most people see CFL’s as a short term solution as a lighting source until solid state lighting (LED’s etc) reaches full maturity.
    SSL lighting meets and exceeds the two advantages of CFL lighting you state above, that is efficiency and potential lifetime.
    Efficiencies in SSL are still steadily increasing and prices will ‘steadily’ decrease as demand increases.
    Harmonics can still be an issue but sensible driver circuits can largely overcome this. SSL’s are dimmable, non-toxic and more ‘rugged’ than any other light source. The question I have is how long before CFL lamps go the way of incandescents and are banned as well?. Would suggest it won’t be that long!

  10. sagar says:

    Well while pondering on the given information we find both plus and the minus of the element yet the plus is more . most imp thing is the change . we must accept and adjust accordingly. not bad atall.

  11. Tim Regan says:

    How does the efficiency of ‘energy saving’ bulbs compare with incandescent bulbs in terms of conversion of electrical energy into light + heat? The reason I ask is that sitting here in the British winter it occurs to me that any heat generated as a by-product of lighting this room is not necessarily wasted energy, and my overall energy consumption may not be significantly affected by swapping light-bulbs. Am I right?

  12. Corky Lima says:

    Thanks for writing about this. It misses a couple of important points. 1) CFLs actually reduce the amount of mercury released into the environment because of their relative efficiency when compared to incandescents. See this calculation: which assumes that 0% of the CFLs are recycled. Popular Mechanics also crunched the numbers on this and found the same thing. 2) dimmable CFLs are available. Although they come at a premium.
    Thanks again. – Corky

  13. Bhavani Prasad says:

    How green are the CFL & Should the incandescent be banned?

    Valid points have been raised about the “Green” ness of the CFL. Proliferation of the use of fluorescents will lead to greater problems due to uncontrolled disposal of mercury and other toxic heavy metals.

    CFLs produce white light; but the white light is not the full spectrum white light. the spectral distribution from two CFLs from two different manufacturers could have the same color temperature, but have intensity distribution at different wavelengths.

    Human body requres full spectrum lights and there are a number of illness associated with inadequate exposure to sunlight or alternative full spectrum lights already, even before the CFLs became popular.

    While the heat from the incandescent may be a negative feature in the tropics, in all areas where room or space heating is required there is nothing wrong in using the incandescent. What is the difference between heat coming from a heater and that coming from the light source. In tropical contries where there is no requirement of heating and when the requirement is for cooling we have to avoid or minimise the use of incandescent lamps.

    As such banning the incandescent is not the prudent solution. We would ban the incandescent for general use and then bring it back as necessary for medical or theraputic applications!!!—–This can happen in all areas other than the tropics.

    Banning is not desirable. Market forces can guide the proper choice as it develops. Today the CFLs are un-naturally priced. Keeping the contents, process, research cost that has gone in, it should be cheaper and the Chinese have demonstrated by bringing in the cost reduction. CFLs should not cost more than twice that of the incandescent for the equivalent replacement from the costing done by experts in the field.

    There should be a mechanism for retrieving and recycling mercury, fluorescent coating powders etc., so that the real cost of CFLs decreases.

  14. Mike Curtis says:

    Fluorescent lights produce ultraviolet, and use fluorescent coatings to convert this to visible light. Color compensated fluorescent lights are widely available. These produce a natural balanced spectrum that is quite easy on the eyes. These also work great for photography and video.

    As already mentioned, electronic ballasts eliminate flicker by converting 50-60 Hz to a much higher frequency.

    Incandescent lighting is no less flawed unless you use color compensated bulbs such as GE Reveal.

    For video, normal fluorescent lighting has a bluish hue, and normal incandescents have a yellowish hue.

    I seriously doubt that CFL’s will ever be as cheap as incandescents. CFL’s are rather complex. Incandescents are just a wire in a glass bulb.

    • Refering to the question of “Cost of CFL and cost of Incandescent”, let us look at the cost of a Tubular Fluorescent Lamp” (TFL) and compare it with the “Compact Fluorescent Lamp” (CFL). The CFL has about 1/6 of the glass, about 1/12 of the coating material and mercury, (on a broad average across different wattages mix), but still cost about 3 times of the TFL, as the manufacturer is pricing it not on production cost but on opportunity & salability. Even now as the volumes have grown and there should be the pricing based on production cost. Should such a change take place, then the CFL would be only about 35% to 50% more than the cost of the incandescent lamp.

      Another issue is about the power factor of CFL. The PCB has components to increase their PF from about 0.45 to about 0.8. If these components are dropped the cost can come down by about 20%. The PF of a set of lamps can be improved by addition of just one large capacity capacitor common for all the lights in a house or office installation at a cost of about 4% of the amount saved in the individual CFl.

      Refering to the other comment that some components in CFL’s have caused fire – it is generally noticed that the capacitor in the CFL PCB has blown off mostly. If we go to low PF CFL these capacitors and the attendent problem of blowing will also be avoided.

      Larger common capacitors compensating the PF for a set of CFLs not only costs less but they also do not have any problems of bursting or causing fire.

  15. David Seal says:

    We had an interesting study looking at the effects of replacing incandescents with CFL’s and found that during winter the reduction in radiated heat from CFL’s required an increase in the heating loads. Also the light output from CFL’s varies in proportion to the ambient temperature so cold applications such as storage areas, hallways etc. do not always yield good light level results. The issue of fire risk has to be examined also as an incandescent light will most likely fail open-circuit whereas a CFL containing many electronic components could suffer from a high resistance fault that could generate enough heat to cause a fire. Flourescent ballasts and low voltage transformers have been known to catch fire.

  16. Jay Hunt says:

    Led lights are great because they are long lasting and consumes less electricity.,~*

  17. Hannah Hall says:

    Incandescent light bulbs will soon be phased out because they waste a lot of energy.-,.

  18. says:

    we are supplier of fluorescent ballast, just everyone saied that LED is good, but the price is high, so many people can not afforad. so now days the fluorescent ballast is the best chioce for poor people.

    • Rumora says:

      I would not agree with you that CFL is for pure people. We can´t compare LED and CFL, because those two light sources are not so similar as it seems.
      LED is constructed of three spikes(red, green, blue) and in our eyes or brain it becomes white light.
      The colour rendering factor is not so high as in case of bulb lihght or fluorescent, because it does not contain full spectar of colours.
      Another fact is present, the shadow is so sharp and straight that it makes “its own” shadow.
      There is a lot of things to talk about it, but the fact is, a few years ago, LED was five times less effective then fluo, but now it is very close to fluo, even price is now acceptable if we calculate the life of lighting(10 years minimum) but can we know what is the progress of new inovations and improvements for cca five years. Also CFS has imrovements, so it depends of us to choose it LED or CFL(energy consumption, life of lighting, benefits, and the most important thing – for what purpose) we still can not make the same and unique calculation. It is still to choose according to purpose and our expecting!

  19. One really cannot conclude that CFL are better that incandescent light bulbs as both have pros and cons in it. Both are context driven where and when they might be needed. Now LED lightind has come into picture which have a lot of advantages over CFL & incandescent light bulbs.

  20. in Europe, bulbs lamps with more than 70W were take out of market and replaced with CFL. Indeed, these CFLs have some drawbacks, but with time these problems will be solved.
    The first example is their power up time wich has been reduced very much by serious companies.

    The advantages of a bulb light like directional beam have been regained with some “ecological” light bulb wich acts like CFLs and look like a bulb lamp.

  21. Horst Droege says:

    There are many valid and good comments here. CFL’s in Asia, there is no disposal for it and most ending up in local landfills. And CFL’s and tubes are widely spread here. Said to see. And i researched on mercury, amazing how many people in China died because of poor manufactoring process and handling.

    LED’s have done a tremendous progress in the last two years. A CFL and tube has about 50-60 lumen/Watt. LED in these days already at around 100 lumen/Watt. LED’s from my manufactorer come with 2 years warranty (you wont have any warranty on Halogen, CFL or incandescent). They save about 40-90% on electricity and about 6 times replacement (lights plus labour) compared to CFL and tubes. And yes, they are more expensive, but putting in above benefits into dollars, the LED will usually have a return of investment within 1-2 years. For Halgen and incandescent its usually below 1 year. I havent found any stock how gives this return !!! Surely they will get cheaper over time, but how long do we want to wait ? I could have still waited on my to computer to get cheaper, I would be sitting and waiting for the last 20 years. Everytime is the right time. So we should make a start now.

    Cheers Horst

  22. vasu says:

    i would say to try LED lights. LED lamps typically include heat management elements such as heat sinks and cooling fins. LED lamps offer long service life and high energy efficiency, but initial costs are higher than those of fluorescent and incandescent lamps. that initial cost hardly matters if you are expecting a lot more benefits out of it. ultimately it willl save ur pocket in terms of electricity bill, u wont get harmed so no doctor charges, and u’ll also contribute somthing towards ur environment.

  23. Suhail says:

    Well..I dont know how green CFLs are but i do know that I am using havells CFLs right now and hadn’t faced any problem till now.I agree with all the points stated above that we should take care of environment and all..Havells LEDs lamps are also there so we can have a look at that also.

  24. Nishant says:

    Well…Cfls would be having some problem but we cant deny the fact that they do also make us save a lot of energy.We can also choose Some good incandescent bulbs like havells have a long range of good looking Incandescent bulbs.We can have a look at that also.

  25. Palash says:

    Earlier I was also not knowing that CFLs have so many drawbacks but after going through some of the articles on internet,I came to know a lot of fact about CFLs.I decided to change my CFLs and start looking for a good brand and after doing a bit of research I found that Havells lighting products are well known and they do have good quality.I changed my CFLs with havells LEDs and now I am a fully relieved man.

  26. Divakar says:

    CFLs are said to have some drawbacks when it comes to something related to nature but we need to see the other side of the coin also..It makes us save a lot of energy and also provide a good look also to our homes.I am using Havells CFLs which are said to save 80% energy when compared to other brands and have a longer life.

  27. jonny says:

    every electronic product has some pros and cons.fluorescent lamps are said to have some drawbacks but we can’t deny the fact that they also help us save a lot of electricity.I am using Havells CFLs which makes me save a lot of electricity and the lighting of this lamp is also just amazing.

  28. Raj says:

    The presence of mercury do makes fluorescent lamps a bit risky but we should look on the other side of the coin also..fluorescent lamps have a lot of advantages also..Use of cfls make us tos ave 80% energy..i am using havells Cfls at present moment and i am Fully satisfied with it.Havells Products are really good.

  29. Kinjal says:

    CFL’s are great way to save our energy bills.They do cost a bit more but the return they give us by saving is just phenominal….I have been using havells fluorescent lamps from quite a long time and they had really made me save a good amount on my electricity bills.

  30. It’s definitely an important issue that not enough people are talking about and I’m glad that I got the chance to see all the angles.

  31. Net-LED says:

    My spouse and I absolutely love your blog and find most of your
    post’s to be just what I’m looking for. can you offer guest writers to write content to suit your needs?
    I wouldn’t mind creating a post or elaborating on some of the subjects you write regarding here. Again, awesome site!

  32. Bhavani Prasad says:

    Original article & discussions are interesting. But one point appears to have been missed. In the areas of colder climate, the apparent lesser efficacy of the Incandescent Lamp is not a serious drawback as the consumers are using other hear sources for space heating. In fact Incandescent lamps should not be banned in some of the state/countries with a significant low temperature period requiring constant heating.

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