Posted on 05/05/2007 11:18:00 AM PDT by John Jorsett
We've been looking in to compact fluorescent bulbs (CFLs) to reduce energy consumption for lighting. Here's what we've learned so far.
Manufacturers say that a 13-18 watt CFL produces light equivalent to a 60w incandescent bulb, an 18-22w CFL is the equivalent of a 75w bulb, and a 23-28w CFL is the equivalent of a 100w bulb. This is based on the "lumens" rating on the side of the box.
In real life, CFL equivalent replacements do not seem quite as bright as incandescents, so you might end up replacing a 60w equivalent with a 75w equivalent and so forth. (The "swirled" designs seem to give off brighter light than the CFLs with a traditional "bulb" design.) But overall, CFLs reduce energy use for lighting by 60%-70%.
Color temperature makes a big difference. The lower the color temperature, the more the light resembles the "warmth" of incandescent bulbs we are all used to (that may sound backwards, but that's how it works). Not all CFLs list the color temperature. The GE "Soft White" has a pleasing, almost incandescent look, while the similarly named Sylvania "Soft White" has a cooler, harsher "fluorescent" look (although some might prefer it for truer color rendering or easier reading).
We found some Sylvania "Warm White" 13w (60w replacement) CFLs at Lowes that have very pleasing light, and their small size allows them to fit most fixtures. The color temperature is listed as 2700K (as compared to their "Daylight" CFL which is listed at 6500K and seems much "harsher".) The 13w "Warm White" CFLs came in a contractor's box of 12 for $27, which is a pretty good deal. They are rated at 800 lumens with a lifetime of 10,000 hours, as compared to a standard GE "Soft White" 60w incandescent, which is rated at 840 lumens with a life of 1000 hours.
Because of their long life and lower energy consumption, CFLs can result in significant savings over the lifetime of the bulb relative to its cost. Manufacturers are quick to point this out, with claims on the packaging of $36+ in energy savings over the life of a 14w (60w equivalent) up to $61 for a 23w (100w equivalent). Your mileage will probably vary.
Most CFLs do not work with dimmers. Manufacturers say it will shorten the bulb life and it voids the warranty. There are special bulbs that work with dimmers, but they are not widely available. If the package does not say the bulb is compatible with dimmers, it probably isn't. (Look at the fine print on the base of the bulb.) We are still looking for a local source for "dimmable" CFLs, as most of our fixtures have dimmers. CFLs are also not intended for use with most photocells and timers.
One thing that is not talked about much is that CFLs emit more ultraviolet (UV) light than an incandescent bulb, which produces virtually none. Light in a CFL starts out as UV from excited gases, and is made visible by phosphors coating the inside of the tube/bulb. Incandescent light is mostly infrared emitted by heating the filament to super high temperatures (leading some to call them "heat bulbs" instead of "light bulbs"). Most of the UV from a CFL is filtered out in the conversion, but there is still some.
Manufacturers say, however, that there is no health risk and that eight hours of exposure to CFL UV is about the same as one minute in full sunlight. But, photographs, artwork, some fabrics, and some photoreactive chemicals used in furniture finishes are susceptible to degradation from any increased levels of UV over time. So this is something to consider.
The Mercury Problem
Finally, CFL critics are quick to point out that CFL bulbs contain mercury, a highly toxic pollutant. This is true. The typical CFL bulb contains approx. 5mg of mercury. (Manufacturers are working to reduce this. Phillips is said to have developed a bulb that only has 1.5mg of mercury.) If the bulb is broken, special care must be taken to properly clean up and dispose of the remnants to prevent health risks. Further, CFLs must be recycled or properly disposed of to prevent the mercury from entering the environment. Here are the federal government guidelines for CFL disposal and cleanup.
What the critics forget to mention, however, is that coal-fired power plants are a major source of mercury pollution. Further, most of this mercury is emitted into the air, and is thus not contained or containable. Mercury in a CFL is already contained unless it is broken, and if properly recycled is fully containable.
We did some rough calculations to determine the mercury pollution impact of CFL v. incandescent bulbs. We used TVA's Kingston plant as an example. It generated 10,161,530 gross megawatts in 2005, and released 643 pounds of mercury into the environment. If our math is correct, this works out to about 0.000028702 milligrams of mercury pollution per watt of electricity generated.
Based on this, a 100w incandescent bulb operated for 8 hours per day 365 days per year causes 8.4mg of mercury pollution. An equivalent 23w CFL bulb will cause 1.9mg of mercury pollution. Assuming a five year life of the bulb, and assuming the bulb is crushed and dumped in a landfill releasing its 5mg of mercury into the environment, the CFL will cause 14mg of mercury pollution over its lifetime as compared to 42mg of mercury pollution for an equivalent number of incandescent bulbs, a reduction of 28mg or 66%.
66% sounds like a lot. But according to DOE estimates, residential power usage is about 35% of the total, and lighting in the average home accounts for about 9.4% of the energy used. Considering that about 64% of TVA power is generated from coal v. hydro and nuclear, the net reduction of mercury emissions if every TVA customer switched to CFL bulbs would only be 4.6 pounds at the Kingston plant, a 0.7% reduction. System-wide, this would be a reduction of nearly 39 pounds annually.
39 pounds doesn't sound like much mercury (even though it's thousands of lethal doses) but it's something. And multiply that for every power system in the U.S. and it adds up.
Plus, we should take pollution controls wherever we can get them. If you figure a 0.7% reduction in coal-fired household energy use and related emissions across the board, system-wide TVA emissions of NOx (nitrogen oxides that cause ozone and smog) could be reduced by 1337 tons, SO2 (sulfur dioxide that causes acid rain and harms plants and stream ecology) by 3220 tons, and CO2 (a greenhouse gas that contributes to global warming) by 735,000 tons (2005 figures). Increased commercial usage of CFL would result in even more reductions.
So CFLs won't save the planet, but they might put off its demise for a month or two.
Back to the CFL mercury problem, a couple of things need to happen right away:
• Consumers need to be educated on proper disposal and cleanup. The packages we purchased do not mention this prominently or at all. One directs you to a website. There should be prominent warnings about health risks and instructions for proper disposal and cleanup on all CFL packaging.
• Local public works officials need to incorporate CFL collection, recycling and/or disposal into their waste management programs.
• Big-box retailers who sell more than 100 CFLs per year (or some other arbitrary figure) should be required to provide on-site recycling centers.
Something else to remember is that since they give off no heat you should be able to put in much brighter CF bulbs in covered fixtures than incandescents.
I take it you don't clip coupons..
Remember that it is on the ‘bluer’ end of the spectrum, heading towards 6000k. It is the color of daylight pretty much. I tend to prefer them lower down in lamps but not in overhead sockets.
Thank you for those URLs, they are just what I need.
A strip of lights would go great under an overhang, like in the the kitchen or workshop attached to the bottom of overhead cabinets to light a bench or countertop.
Yes, but they are tinting some in more colors, including warmer color light down in the 4,000s.
I tend to prefer them lower down in lamps but not in overhead sockets.
Do you find them terribly directional?
I saw that sunset one and meant to order it, but forgot due to coffee deprivation.
Let us know what you think. I’ll order the sunset ones this week if I get the chance. I mainly want to see how bugs react to the thing. :)
Do you think bugs will react differently to different color lights?
The yellow bulbs they market for the outdoors seem to help but I need something that is not quite so yellow and not so intense. Our outside deck uses rope lights, which the bugs don’t know what to do with, but I need some lights over tables that would be suitable for reading...without attracting a winged armada as soon as you turn it on.
I use a lot of 40w incandescents but can’t imagine how unbright their 25 LED would be.
Yeah, that was pretty much yesterday. I decide to move on today. I decide to be hysterical about upcoming cicada swarm, even though I’d swear I’ve never seen them in all my years in WI I’m told they’re coming at the end of May.
Maybe I give them the lightbulb that stopped working and they’ll bury it with them for the next 17 years?
Cool!
I doubt if it is very bright but the tables outside have lights that hang down to the table...so just a bit of a boost is needed for reading...but everything I have tried either brings in the bugs or makes the light unpleasant.
1)The lights will not operate below -10F, and are subject decreased light output at low temperatures, such as an unheated basement, and garage.
2) AT normal temperatures the lights take 90 sec to reach full output....therefore you have to wait 90 sec for the garage light to properly light.
3)The light will explode if it gets wet, hence require outside protection, such as a glass cover, in most installation this will require expensive alterations to the outside lighting fixture.
4) In order to reach the maximum expected light life, the light has to remain on for a minimum of 3 hours; switching on and off within a 3 hour period will reduce the life expectancy.
5) The light contains mercury....need I say more?
6)The lights cause Radio Frequency interference, when switched on, while this may have a minor impact in your house, think of millions of these lights being switched on all over the nation....the Radio Frequency interference will wipe out the standard broadcast reception, and may extend into the TV frequencies, and satellite reception....
7) My observation: the color temperature of these lamps is "cold", and is guaranteed to mess up your house decor.
Have a look at this site: have a look
Now THAT is something to be concerned about. :-)
Seriously, just throw the bulb out in the trash. Mama Earth is big enough to handle it.
Yes, I understand what you mean. Those yellow incandescent bug lights don’t work too well for bugs, either.
We’ve got jasmine in bloom right now and turning on a light outside at night brings in some of the largest moths you have ever seen. Hitchcock would love it here!
We need photos of those giant Texas moths! I love Hitchcck, so I would like giant moths. I’ll just wear my bee keeper hat so I won’t swallow any.
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