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World’s Most Efficient LED Light Bulb – Philips Award Winning LED Bulb

10 Mar

The Philips “Award Winning LED Bulb” is finally in stores and ready for purchase. The award that the name refers to is the Department of Energy’s L-Prize which laid out standards for a “next generation” light bulb. Philips Lighting ultimately won the competition after meeting or exceeding all criteria and claimed a $10 million prize. At 94 lumens/Watt, this bulb is currently the world’s most efficient A19 form factor bulb. The total power consumption is 10 Watts for a total output of 940 lumens. The estimated lifespan of the bulb is 30,000 hours which comes out to over 27 years when used 3 hours per day. Along with its very high efficiency, this bulb also boasts a color rendering index of 92 which helps to ensure that colors are accurately rendered. The color temperature is rated at 2700K which is standard for incandescent bulbs and warmer than most LED and compact fluorescent bulbs.

Like Philips’ first generation LED bulb, this uses remote phosphor technology to convert non-white light to white light. The first generation bulb used three blue LEDs behind each yellow plastic lens. This new bulb uses three blue and three red LEDs. This combination helps improve the color rendering index from 80 with the previous bulb, to 92 with the new bulb. After some prying, I was able to get the plastic lenses off to see what it looked like underneath.


Each bulb contains three groupings of three blue and three red LEDS. The yellow plastic lens that covers them contains a phosphor that re-emits white light.

The smooth heatsink doesn’t get very hot even after several hours of operation. It becomes too hot to hold onto for more than 2-3 seconds, but it is definitely cooler than many other LED bulbs that I have tested.

The blub is dimmable using leading-edge dimmers according to the box. I tested it out with a dimmer and found that it gives off a quiet buzz when on a dimmer even when at full brightness. The buzzing is probably loud enough to be distracting if you are using this as a reading light. On the subject of dimmability, I found that the bulb’s light output becomes a very ugly color when dimmed. As you begin to dim, the light turns bluish and then it becomes pink. Overall, the dimming characteristics of this bulb are quite poor. My favorite dimmable bulb is still the Utilitech 60W equivalent.

The light output of the bulb is very good. The design allows light to be cast in all directions in a fashion similar to a standard incandescent bulb. Also, at 940 lumens, this bulb is one of the brightest available with the exception of Philips’ own 75 Watt equivalent bulb that puts out 1100 lumens. The light quality at full brightness is good enough that nobody would likely suspect that it isn’t an incandescent bulb if it is hidden by a lamp shade.

As for the design of the bulb, some will love it and some will hate it. The yellow plastic lenses on this new bulb are an ugly yellow in contrast to the nice golden yellow lenses on the first generation bulb. Personally, I think that is is cool looking bulb, but the first generation is much more visually appealing to me (the ugly yellow lenses are really quite hideous).

The initial retail price of the Philips L-Prize inspired bulb will be $50. Yes, FIFTY DOLLARS! The first generation 60 Watt equivalent bulb can be had for less than $25 now and I honestly would recommend it over this new “Award winning LED bulb”. The old bulb puts out 800 lumens with 12.5 Watts of electricity. So, yes, it is significantly less efficient than the new bulb and the color rendering index isn’t as good. Even as an LED bulb enthusiast I wouldn’t spend $50 for this new bulb given what I know now about it. I hope that this review helps other LED enthusiasts decide to skip it. With luck, Philips will be forced to bring the price down when they realize that even the early adopters don’t want it at this price.

So in conclusion, this is an excellent bulb if you need extreme efficiency such as in a hotel lobby or other places that have the lights on 24 hours per day. It will not only save on electricity, but also on maintenance costs to replace bulbs since at 30,000 hours of life it will take nearly 4 years of continuous use before they start to fail. For home use though, I would recommend the first generation Philips LED bulb since it is cheaper and still puts out plenty of high quality light.

Be sure to check out the video below for a hands on review!

Investigating LED Bulb Power Factors

29 Jan

I’m not an electrical engineer so my analysis of this topic might have some slight misconceptions. Anyone who is more knowledgeable on the subject of power factors and alternating current is welcomed to submit information via the comments.

If you are an energy conscious consumer, you likely take note of the key parameters printed on the packaging of the light bulbs you buy. Lumens and Watts are probably the two biggest factors that most people pay attention to with lumens per Watt being a helpful guide of the overall efficiency of the bulb. But are lumens and Watts the whole story? Is there a hidden factor that makes the bulb use more energy than the packaging would have you believe? You are not alone if you think that an LED bulb that says it uses 13 Watts, uses 13 Watts. There is another factor that has to be considered, power factor.

Power factor (to paraphrase Wikipedia and other sources) is the ratio between real power and apparent power. Real power is how much power the load is actually using and apparent power is the product of how much current is flowing and the Voltage. Real power is measured in Watts, and apparent power is measured in Volt Amps (VA). If you think back to when you learned about electricity fundamentals, you might remember that current (Amps) times Voltage equals Watts. This is true for a direct current system and it is also true for an alternating current system with a power factor of 1.0. An old fashioned incandescent light bulb, due to being a purely resistive load, has a power factor of 1.0. However, many electrical devices including LED and CFL light bulbs have power factors less than 1.0. What this means is that while they might be rated at 13 Watts real power, they will draw more current than you would suspect. Assuming a 120V system, 13 Watts should require approximately .11 Amps (120V*.11A = ~13W). In reality, a typical LED light bulb has a power factor of .6 (and as low as .2 or less!). This means that the apparent power of the bulb is more like ~22VA (13Watt/.6 power factor). Remembering that apparent power is current * volts you can find that with a .6 power factor this bulb is using ~.18 Amps.

The good news is that residential power meters typically measure real power and not apparent power…for now. This means that you are charged by the kWh and not Volt Amp hour. However, utilities are now beginning to install “smart meters” that are capable of measuring your home’s overall power factor (the average power factor of all connected loads) and charging you accordingly. For now, it seems like you are in the clear and you can trust the numbers printed on your bulb’s packaging.

Okay, so this means that LED bulbs are good for your wallet, but are they good for the environment? The short answer is yes. They consume up to 85% less energy than an equivalent incandescent light bulb and contain no hazardous mercury like their compact fluorescent ancestors. The long answer is that power factors less than 1.0 do cause a greater demand on the power grid which results in the power plant having to burn more fuel to supply the load. To use an exaggerated example, if a 1 kilowatt load has a power factor of .2, then it will take 5 kilovolt-amps (1/.2) to supply the needed power. This means that five times the current must flow through distribution lines, generators, and transformers. If a transformer is 98% efficient, it is now 98% efficient with five times the current…in other words, more wasted energy.

So that is the back story on power factors. I decided to sit down with my LED bulbs and see how efficient they really were. I built a test setup with a dimmer so that I could test the bulbs at varying brightness levels. Unsurprisingly, the power factor of LED bulbs is less than 1.0. At full brightness, my two Utilitech 60W equivalent bulbs have a power factor of approximately 0.6. My Philips Ambient 75W equivalent also has a full brightness power factor of about 0.6. Winning the power factor competition, the Ecosmart 60W equivalent LED has a full brightness power factor of about 0.9.

Notice that I stated the full brightness power factor of these bulbs. As I began to dim them, the power factor drops lower and lower as the knob is turned toward dim. At full dim, most of the bulbs have power factors of around 0.2. Now here is the interesting part; the bulbs do progressively consume fewer Watts (real power) as they are dimmed, however, the apparent power actually begins to go UP as the bulbs are dimmed. In my tests, I found that dimming the bulbs to about 2/3 brightness actually resulted in a higher overall current flow. This is due to the power factor decreasing at a greater rate than the decrease in current flow. Very interesting! Once again though, consumers are charged real power and therefore you will save money by dimming your LED bulbs. If your utility company ever switches to apparent power billing, then it will actually cost less to run your lights at full brightness than somewhat dimmed.

The below video is of me experimenting with several of my LED bulbs. It is about 12 minutes long, but I think that you will learn quite a bit about how these bulbs behave while on a dimmer. Click here for 1080P version.

Philips Ambient 75W LED Bulb Review

24 Jan

The Philips 17-Watt A21 LED Light Bulb features lead-free and mercury-free construction and is equivalent to a 75-watt bulb. This long-lasting LED bulb casts a soft white glow that can shine up to 25,000 hours and resists fading fabrics and furnishings.

  • Brightness: 1,100 lumens
  • Estimated yearly energy cost: $2.05 (Based on 3 hrs/day, 11c/KWh. Costs depend on rates and use)
  • Life: 22.8 years (Based on 3 hrs/day)
  • Light appearance: 2700K (Soft White)
  • Energy Used: 17 watts (Equivalent to a 75 watt standard incandescent light bulb)
  • Lumens per Watt: 14.7
  • Mercury-free and lead-free construction for safety
  • Uses 77.3% less energy compared to a standard incandescent light bulb
  • For use indoors and outdoors. Can you used in tables lamps and many difference light fixtures
  • A21 shape with a medium base
  • Dimmable: Yes
  • MFG Brand Name : Philips
  • MFG Model # : 418400
  • MFG Part # : 418400

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