The recently released OSRAM Life Cycle Assessment study (executive summary) appears to be one of the most comprehensive studies so far. However, it still isn’t done properly.
The 3 base-cases which the whole study hinges upon have all the usual flaws:
For comparability reasons in the study, it was assumed that all three lamps would have a light output between 345 to 420 lm during their whole lifetime, and then burn out.”
a) Very low lumen lamps were chosen in this study, most likely because Osram still can’t make an LED produce more light than the equivalent of an 25W incandescent, which is good for absolutely nothing. A 25W incandescent can be used for mood lighting, an 8W LED can’t be used for anything but a scary night light.
b) A 40W tandard incandescent bulb gives 410 lumen (xenon-filled bulbs an extra 10%) whereas a typical high quality 7-8W CFL gives around 350 lumen and a 7-8W LED around the same, or less.
c) And then CFLs and LEDs lose output with age – more the longer they last. For example, in a Swedish consumer test (Råd & Rön 3/2008) a 7W Osram Superstar classic A CFLs had lost 27% of their initial output after 6000 hours.
“An extra analysis was done that took the gradual reduction of brightness into account. The difference was too small to impact results, though.”
Ah, but that’s only because very low lumen lamps were chosen for the study. The higher output lamps you compare, the more CFLs and LEDs tend to lose with age. And as they were already weaker than an equivalent 40W to begin with, this adds to the difference. A 27% decrease is not negligible!
Thus, it is not a correct comparison and all following numbers and conclusions in the study equally faulty.
“To ensure comparability of the three lamp types a lifetime of 25,000 hours was taken a reference parameter which was evened out by the number of lamps used. This way, the lifetime of 25 incandescent bulbs (25,000 hours) equals the lifetime of 2.5 compact fluorescent lamps, which equals the lifetime of one Parathom LED lamp.”
a) Halogen Energy Savers, which last 2000-3000 hours and use 25-45% less energy, were not included!
b) Maybe some of Osram’s long-life CFL models last 10 000 hours if just left burning, but as it is explicitly stated that “turn-on-and-off cycles were excluded from the study” and an Osram representative confirmed the earlier study that showed frequent switching may shorten life with up to 85%…
c) We only have Osram’s word for their LED lasting 25 000 hours…
“..a correlated color temperature between 2700 – 3000 K (warm white), a colour rendering index of ≥ 80 and a Classic A shape with E27 socket. All lamps provide comparable luminous flux and all are warm white lamps but the fact of a cold perception of the light from different emission spectra of the lamp types is not considered.”
In other words: besides not being equal in output, these 3 lamp base-cases are not comparable quality-wise, or even appearance-wise, only in bulb-shape & socket.
a) CRI ≥ 80 = mediocre colour rendering capacity in CFL and LED, to be compared with CRI 99-100 for incandescent and halogen.
b) As Osram does not state exactly which model CFL and LED they have used, t’s hard to know what that specific lamp looks like. The ones I’ve seen so far (see my Energy savers review) have not been comparable to incandescent light colour, radiance and quality, even if CFLs have improved markedly over the last decade and Osram makes some of the most incandescent-like CFLs on the market.
“The production of the GLS and CFL takes place in Europe. For the Parathom LED lamp, production of the Golden Dragon LEDs is located in Germany (frontend) and Malaysia (backend) and the production of the LED lamp in China. The location of the use phase, end of life, and any other processes was Europe.”
This may be true of Osram CFLs, but most CFLs on the market are either low-budget lamps imported from China or manufacturers have their factories there. Sylvania says their ballasts are manufacturered in different places and sent to be assembled into CFLs in another, sometimes another country.
“The heating benefit of a GLS always leads to a discussion. This chapter estimates the actual benefit of heating losses during usage. By assuming 250 heating days, 1000 hours of GLS burning time per year, 75% GLS lighting during heating days, and heating with natural gas, it would lead to a reduction of 17 kg CO2 over 25.000 hours. This saved amount is negligible in comparison to the whole life cycle, and there is no reason to hold on that argument. Furthermore, the heating benefit could also serve as a disadvantage when cooling is necessary.”
At least they mention the heat replacement effect, even if they consider it “negligible” – except when it needs to be air-conditioned away, then it suddenly counts (as always).
Poor power factor is not even mentioned.
With correction for the above factors, the outcome would be less advantageous for the LED and CFL.
Yes, they may still save something when compared with the poorest performing incandescents – a matter of quantity vs quality – but not nearly as much as claimed in this biased study, and even less when compared to the best halogen energy savers.
What could be expected? Osram is a lamp manufacturer well known to want to sell more CFLs and LEDs and get rid of the unprofitable incandescent lamps altogether.
Sorry Osram, it was an admirable effort, but do try to get your basic numbers right the next time and the results may be more belieavble, even if not as spectacular.
P.S. When do we get to see the whole study and not just the summary?