3l. CFL Analysis - Efficacy

Though CFLs may give a little more light (lumen) per watt than incandescent lamps - a normal quality-quantity trade-off - the "5 times more" is only a nominal value for some of the best, top brand, bare tube 'single-envelope' CFTs & CFLs:

a) in the beginning;
b) in optimal burning position, at optimal temperature & humidity, in optimal luminaire;
c) if they have a good power factor;
d) if the heat replacement effect is ignored;
f) if they last as long as promised (without losing too much output towards the end).

"During 2004, the Test Laboratory then a part of the Swedish Consumer Agency (now a part of Swedish Energy Agency) carried out its second ad hoc testing of 20 different CFLs from Osram, GE, Philips, IKEA and Sylvania. The testing authority concluded that there was no correlation between price and performance of the CFLs.

The information on packaging was often deficient in terms of light quantity. Many models had light output claims that could only be achieved at the optimum operating temperature and/or in some optimum burning position that achieved an optimum internal temperature.

"Many light output claims were outright exaggeration, often by about 15 percent and in a few extreme cases by 25 percent. Furthermore, it was common that the indicated life was inaccurate."[emphasis added] [1]

Other consumer tests have found the poorest performing bulbs in each test to give >15%, 19%, 22%, 33%, 34%, 65% less light than stated, while a few of the best gave slightly more (initially), and most somewhat under stated lumens. [2, 3, 4, 5, 6, 7]

Update 29 Aug: A new test by The Telegraph sample 11W CFLs to give only 58% of the light from the claimed equivalent 60W incandescent lamps. [8]

1. Swedish Energy Agency: Compact Fluorescents in Residential Lighting
2. Vielen Sparlampen geht das Licht zu früh aus
3. 14 Sparlampen im Test
4. Råd & Rön, 1/2008
5. Ica-Kuriren, 3/2008
6. Öko-Test Themen-Special: Energiesparlampe versus Glühbirne
7. Die Tester: Energiesparlampen
8. Energy saving light bulbs offer dim future

3k. CFL Analysis - Light Reduction

Unlike halogen and most incandescent lamps, all fluorescent and HID lamps lose output with age; some more than others, especially covered and reflector CFLs. 10% after 1000 hours for bare tubes and more and as they age, is considered normal in the lighting industry. Though the general public is usually not informed of this fact and will end up with less light than they thought they were buying if they follow the recommended conversion charts.

U.S. Department of Energy tested ENERGY STAR-labeled lamps and found that:

"In Cycle Four, 38% CFL samples failed to meet the requirement of lumen maintenance at 40% rated life, and the majority of covered lamps and reflector lamps failed this requirement with the exception of two models from a certain manufacturer." [1]

In a 2008 Swedish consumer test, Philips, Osram and IKEAs bare tubes had lost a mean of 19% after 6000 hrs, Philips & Osram covered bulbs a mean of 25%, and Ikea bulbs 30-100% (= some didn't last long enough to measure). [2]

And these are some of the best CFLs on the market. Lower end lamps can be expected to lose even more.

1. Energy Star Lighting Verification Program
2. Råd & Rön 1/2008

Update Dec 2: Finally, some journalists are starting to actually read consumer and governmental tests instead of just mindlessly trusting the inflated propaganda from EU, Energy Star and Energy Saving Trust.

Energy saving light bulbs get dimmer over time

Just as I've been saying. Every lighting professional knows this and plans for it. And you don't even have to check consumer tests: it's right there in manufacturer catalogues (if you know what you're looking for) and manufacturers won't deny it if asked; they're just not going to volunteer that information to the public if you don't ask.

3j. CFL Analysis - Lifespan

According to the few consumer tests that test CFLs for that long, life span seems to have improved over the last decade for the best lamps, though not all CFLs work as long as promised.

* In a German test published January 2009, Osram & Philips CFLs lasted the full 15 500 hours - though with decreasing output - whereas 20% of IKEAs lamps went out before 3000 hrs and most reflector lamps died fairly soon. The tendency was for cheaper lamps to go out sooner. [1]

* Another German test from Dec 2008 gave "less than good results". The first lamps went out after 1500 hours. [2] (However, the exact details were not presented.)

* In a Swiss test from November 2007, Noser, IKEA and Megaman had fallouts before 3000 hrs, whereas the other 11 kept burning. [3]

* In a Swedish test from 2008, various lamp models and wattages from 3 common brands were tested for 6000 hours. 3 of the 4 tested IKEA lamps lasted the 6000 hrs, but one model an average of only 4398 hours. 11 of 14 Osram models (promising 6-15 000 hrs) passed the 6000 hour test, and the remaining 3 (sold as '6000 hrs') lasted 4984 - 5911 hours. 8 of 15 Philips lamps kept burning at 6000 hrs and the other 7 went out between 3189 and 5837 hours, of which one (marked '10 000 hrs') lasted only 4244 hrs and 4 of 8 sold as '8000 hrs' lasted only between 5178 and 5837 hours. [4]

And this is when tested in lab conditions with bulbs burning openly without shades, at optimal temperature, burning position etc. In home luminaires with insufficient air flow and real life situations, e.g. when turned on and off often, life rate may in many cases turn out to be significantly shorter.

One of the most common complaints from disgruntled customers is premature failure after only a few hours, days, weeks or years, way short of the life rate stated on the package; sometimes due to poor lamp quality, sometimes from using good lamps in the wrong luminaires so they overheat, or flicking then on-and-off too often.

Example of long list of typical complaints can be found in the comments section of this (substandard) CFL test by Popular Mechanics and here: Compact Flourescent Light Bulbs - Lifespan A recent article also brings attention to this problem:
New York Times: "Do New Bulbs Save Energy if They Don’t Work?"

"A study published in 1998 examined CFL performance with five different operating cycles. It found that when the length of time the lamps were on was reduced from 3 hours to 1 hour, the lamp lasted for 80 percent of its rated life. When reduced to 15 min and 5 min, the lamp lasted for 30 percent and 15 percent, respectively, of its rated life." [5]

Update 8 Sept: A spokesman for the Energy Saving Trust confirms that frequent switching may reduce CFL life: “Regularly flicking a bulb on for a brief moment and then off again is not recommended as it can shorten the lifetime of the bulb." [6]
When CFLs fail prematurely, calculated long-term savings of course go down the drain.

1. Konsumo: Energiesparlampen-Test: - Zweifel beseitigt
2. Öko-test Online: Energiesparlampe versus Glühbirne
3. Arcotronic AG: 14 Sparlampen im Test
4. Råd & Rön: Lågenergilampor, 1/2008
5. Chen W, Davis R, and Ji Y. 1998. “An Investigation of the Effect of Operating Cycles on the Life of Compact Fluorescent Lamps.”
6. Lifespan of energy-saving bulbs reduced by repeated switching