The Many Problems With CFL Light Bulbs

You have doubtless come across Compact Fluorescent Lamps (CFLs) on sale in shops and in use in offices and domestic settings. They’ve been around a while yet despite their claims to deliver low-energy lighting and hence energy savings (for which read “money savings”) they have hardly taken off at all.

And probably never will… So let’s see why that should be.

It’s A Saving Jim, But Not As We Know It

When you take into account the purchase price and replacement frequency of CFLs, as energy saving light bulbs go they are not that great in terms of the true total cost of ownership. Certainly, compared to an equivalent LED bulb you would have to be mad to opt to either stay with incandescent lighting or switch to CFL.

Type Watts Purchase Lifespan Total Cost at 25,000 Hours
LED 6W £10 25,000 £28.75
CFL 15W £4 10,000 £56.88
Incandescent 50W £1 2,000 £168.75

The table above summarises Total Cost of Ownership normalized over 25,000 hours – basically the cost to purchase the bulbs (and replacements) plus the cost of the electricity used.

The LED not only wins hands down but if you discount the high purchase price then in fact it cost slightly less then twice what it cost to buy in order to run it. A ratio of 2:1 running:purchase costs. The incandescent has a ratio of about 150:1. You really do get what you pay for!

Put simply, although they do save money, CFLs don’t save enough money to make enough of a difference to most people. Which is likely the number one reason they never really caught on – people typically act in their own self interest and CFLs don’t provide sufficient savings to appeal.

Pretty In Pink Green

As a breed, CFLs are without doubt ungainly bordering on outright ugly and often exhibit an unpleasant garish light quality. The whole point of artificial light for most people is to illuminate their surroundings in an attractive way.

Who wants to come home to a house that looks like a badly lit municipal office or see a ghostly green-tinged Herman Munster peering back in the mirror?

Slow To Start

CFL bulbs have relatively poor start-up characteristics with a noticeable delay before maximum luminosity is achieved. They can also suffer a reduced life span if switched on and off frequently, which rather defeats one of their promoted benefits and principal reasons for saving money – longer life span than an incandescent lamp.

There is also a pervasive myth that they use significantly more energy during the warm-up period (and thus end up even less efficient than incandescent bulbs!) but it’s not actually true.

Still, if you want a light that delivers the moment it’s switched on (popping into the bathroom for instance) then CFLs will disappoint.

Limited Application

Only very few, specially designed CFL bulbs can be dimmed. So if you have and wish to continue using dimmer switches you have a problem (see also advisory caution regarding fire risks below).

Furthermore they cannot be used to replace halogen spot lamps (for example GU10 mains voltage and low voltage MR16 12v fittings) for several basic reasons:

  • They are rubbish at projecting directional light and simply not bright enough to work with reflectors;
  • Their shape and size usually render them a poor or impossible fit for existing spotlight fittings;
  • The recesses and enclosures typically used to house spot lamps can pose a fire risk for CFLs (see below).

Fire Risks

CFLs are not only not suitable for many types of lighting application (as noted above) but can in fact pose a serious fire risk to the unwary, as this San Francisco Fire Department CFL Safey Information points out.

In summary, don’t use them in an inverted position or in enclosed/recessed fitting because the heat will rise and fry the electronics in the base, likely then starting an electrical fire. Also don’t use them outdoors unless they are properly protected from the elements (yet not so enclosed as to risk combustion).

And absolutely don’t use them on a lighting circuit controlled by a dimmer switch unless they are clearly marked as dimmable AND the dimmer switch itself is compatible.

Health Risks

Other than being burned to death (see above) obviously… CFLs emit relatively high levels of ultra violet (UV) radiation. The same stuff that causes sunburn and skin cancer! Admittedly this is primarily found in “single envelope” bulbs (the ones with the spiral tube exposed) and is generally only an issue if in close proximity (such as a reading lamp).

Additionally, CFLs (in common with regular fluorescent lighting) also exhibit a high frequency flicker which can adversely affect people with photosensitive eye conditions and indeed induce headaches and eye strain in just about anyone.

And of course, there is the mercury…

Not So Green After All

CFL bulbs are not as “green” as many assume. Being more complicated than incandescent bulbs, they need more materials, more processing, and therefore more energy to manufacture. True, it isn’t necessary to manufacture so many because they last on average about 8-10 times longer, so this just about evens things out, but it does actually cost significantly more to manufacture an individual CFL than an equivalent incandescent bulb. This Life Cycle Analysis of CFLs puts some interesting flesh on the bones.

They also contain small, yet not entirely insignificant, quantities of mercury vapour. Mercury, a heavy metal like lead, is a “neurotoxin” and extremely poisonous and damaging to humans whether ingested, inhaled, or simply in contact with the skin. Sure, this is usually only an issue if you break one (or set it on fire – see above, again) but en masse it is also an issue because of disposal requirements.

Put simply, used CFL light bulbs constitute a form of hazardous waste and should be disposed of appropriately at a recycling facility. You can of course ignore this chore (as in reality do most people) and simply dump them in the regular waste, but in that case you might as well dump your green credentials along with your discarded light bulb.

It’s all very worthy making an effort to stop global warming, but at the expense of the environment and public health? But that’s good intentions for you… all too often a fertile breeding ground for ironic and unintended consequences (Socialism anyone?). Check out this information about CFL hazards…

Even The Lighting Industry Dislikes CFLs

Finally, if you think CFL bulbs look like a poor replacement for incandescent bulbs, that’s nothing compared to how poorly the lighting industry itself thinks of these products (and they make and sell them!).

There is almost zero allocation for improving CFLs in the research and development budgets of the major lighting corporations, despite the well documented flaws that you might think would keep their researchers busy for years.

Vast sums of money however are being spent on developing LED lighting. And that’s because not only is LED technology cleaner, greener and financially superior, but the future development of the underlying technology is almost entirely predictable.

Light Emitting Diodes are essentially semi-conductors, and just as that other popular use for semi-conductors (computer chips) took off like a rocket on a tragectory described by to Moore’s Law, so the exact same thing is certain to happen with LEDs as per Haitz’s Law.


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