Before we had LEDs, there were compact fluorescent lamps, or CFLs for short. CFLs are fluorescent lamps that emit light from a mix of phosphors inside the bulb, and were designed to replace incandescent lamps (a lamp that produces light as a result of being heated). When compared to an incandescent bulb producing the same amount of light, CFLs use one-fifth to one-third the electric power, and last eight to fifteen times longer. Like all fluorescent lamps, CFLs contain toxic mercury, which complicates their disposal. In many countries, governments have established recycling schemes for CFLs and glass generally. A light-emitting diode, or LED for short, is a lamp that emits light in a very narrow band of wavelengths. Because of this, LED’s are far more energy efficient than incandescent or fluorescent lights, which emit light in a much wider band of wavelengths. LED’s produce light that renders a color similar (but not identical) to natural daylight, which is measured on a scale called CRI, or Color Rendering Index.

CRI’s range from 0-100, 100 being identical to natural daylight. Typical LED’s are around 70-95 CRI, but it is not recommended to put anything indoors below 75 CRI. Like incandescent lamps and unlike most fluorescent lamps, LEDs come to full brightness without need for a warm-up time. So how much more efficient are LED’s? On average, an incandescent bulb may last around 1000 hours, while a fluorescent (CFL) bulb producing the same amount of light (in Lumens) may last around 8,000 hours, and an equivalent LED bulb may last around 25,000 hours. Mock BlindsBecause of their efficiency, LED’s are generally more costly, but the energy saved on your electric bill pays off when compared to incandescent bulbs.Car Seat Upholstery Dye When looking at a 60-Watt incandescent bulb, the price of running that single bulb for 20 years (based on 6 hours per day) is $360. T Shirts Yin Yang

The price of running a 60-Watt LED equivalent for the same amount of time is only $72. So while an incandescent might only be around $1.00/bulb in comparison to $10.00/bulb for the LED, think about how much you would save by replacing every bulb in your house! The 20-year savings on replacing a single candescent bulb with an LED would be $288, but when you multiply that by (as example) 20 light bulbs in your home, you’re saving $5760 in the long run. If you have even more, lets say (as example) 40 light bulbs in your home, you’re saving $11,520 over 20 years. That’s $576 dollars a year! While these numbers are estimates, it is clear that LED’s are the most energy efficient option for light bulbs on the market, and the savings from switching out your old incandescent bulbs can keep some extra dough in your pocket. When it comes to ultra-efficient light bulbs, consumers could soon see an alternative on store shelves to LEDs and CFLs. But they may not find the new bulb a better option.

As I detailed in a story for today’s paper, a startup company called Finally has come out with a bulb based on induction technology. That’s the same electromagnetic principle that allows Apple Watch by resting them on a charging pad, rather than having to plug them in directly. Finally promises that among all energy efficient bulbs, its are the most like the old incandescents. They have a similar shape and give off the same color of light. Those selling points, by themselves, aren’t what they used to be. Many of the latest LED bulbs come in shapes that look like the old incandescent bulbs. And you can find plenty of LED and CFL bulbs these days that offer the same color of light as the old bulbs. You just have to know how to read the labels on their packages — you’re looking for bulbs that say they give off “soft white” light, or ones that have a color temperature of around 2700 Kelvin (typically abbreviated as K). But there are other reasons you may not want to buy Finally’s new bulbs. 

As I detailed in my article, Finally’s bulbs are more expensive than CFLs and many LEDs and they aren’t as energy efficient as LEDs. Also, unlike many of the latest LEDs, they aren’t dimmable. And the bulbs have other shortcomings that I didn’t have room to cover in my article. One such drawback is that they contain mercury, a toxic substance. Mercury is also present in CFLs and has been one of the factors that has discouraged some consumers from buying those bulbs. When a CFL breaks, some of the mercury can leak out, which can pose a hazard unless it is cleaned up immediately. Similarly, if a Finally bulb were to break, some of its mercury could leak. Finally says nearly all the mercury in its bulbs is in solid form, and its bulbs contain less of the toxic substance than is found in a typical CFL bulb, implying that they pose less of a risk that CFLs. Another shortcoming of the Finally bulbs is that they are slow to light up. As the company notes, the bulbs turn on instantly when you flick on a switch.

But they’re reminiscent of CFLs in that way in that they can take 10 to 20 seconds to reach their full brightness. I tested a Finally bulb in a bathroom light fixture in between two LED bulbs. The difference was noticeable. When I flipped the switch, the LED bulbs immediately gave off a bright, soft warm light bright. By contrast, the the Finally bulb was somewhat dim and gave off a pinkish-red glow. Only gradually did it approach the brightness and color of the LED lights. So, while Finally’s bulbs offer another efficient alternative to incandescent bulbs, they aren’t the perfect replacement the company promises. Indeed, from my experience, it’s hard to beat the latest LEDs. Photo: Two 60-watt equivalent energy efficient bulbs: a Philips LED light bulb (left) and an induction bulb from startup company Finally Light Bulb (Troy Wolverton, Mercury News). Tags: CFL bulbs, energy efficiency, green tech, LED bulbs, light bulbs Compact fluorescent lights (CFLs) use about a quarter of the electricity of traditional incandescent light bulbs, reducing energy costs for consumers. 

By conserving electricity, CFLs also avoid some of the mercury emissions from power plants that burn coal. Burning coal is a far larger source of mercury in our environment and a far bigger risk to our health.  In fact, we’ve calculated that using a CFL results in less than half of the mercury emissions of using a 100 W incandescent light bulb. However, CFLs themselves contain a small amount of mercury, which has led to some questions about whether they are safe to use. We’ve taken a close look at this issue, and we believe that CFLs are the right choice for those concerned about both their health and their energy bills. The amount of mercury contained in a CFL is very small — a typical bulb today contains about 3mg.  To put that amount in perspective, there is up to five times that amount of mercury in the watch battery on your wrist; quite notably, between 60 to 200 times that amount of mercury in a single “silver” dental filling in people’s mouths, depending on the size of the filling;

100 to 200 times that amount in the old-style thermometers many people still have in their medicine cabinets; 200 times that amount per switch in the light switches of certain freezers; and about 500 times that amount in thermostats on the walls of people’s homes. (These are conservative estimates based on comparison to a bulb with 5 mg of mercury.) CFLs also use the same technology as the linear fluorescent tubes we have been using in our schools, offices and hospitals for over 50 years. Those tubes can contain up to 100 mg of mercury each. Still, you may be concerned that a delicate glass bulb is different from the watch on your wrist: if a CFL breaks, some of the mercury inside can escape into your home.  Some news reports have raised concerns that broken CFLs could result in harmful air concentrations of mercury in the room where the bulb is broken, but  these reports are based on worst-case situations, assuming common sense measures (such as ventilating the room) are ignored.  

If a bulb does break in your home, don’t panic.  The small amount emitted is unlikely to be harmful, and you can use simple cleanup procedures to further minimize any exposures.  Keep kids away from the breakage, open a window and carefully clean up the pieces and place them in a ziplock bag for proper disposal. While it is sensible to handle broken CFLs with care, by far the most important step people can take to reduce mercury exposure in their daily lives is to avoid eating fish contaminated with mercury. Eating fish is the main source of mercury exposure for Americans, and the form of mercury found in fish is more toxic than the form used in CFLs (or other household products).  While fish is part of a healthy diet, people should take care to choose the types of fish which contain the least amount of mercury, particularly if they are pregnant or nursing. NRDC’s website contains recommendations for choosing fish that contain the least amount of mercury. /mercury for a printable shopping guide to safe fish.