First published on Patrick Dunford
Any electronic geek such as myself knows that LEDs used to be these little red, green or orange pilot lights on electrical appliances, just a little speck of light that would tell you a device was powered up or maybe your radio was tuned in correctly. Seven segment displays was another major application of LEDs on calculators and some early watches. I can well remember the futuristic looking Texas Instrument plastic LED watches that had to be turned on with a button press to show the time. Although LEDs are generally much more efficient than incandescent bulbs, in battery devices the power consumption can still be significant, and more attractive and significantly more efficient backlit LCD seven segmenters becoming available relegated this type of LED display out of contention a long time ago now and it is rare to see them in anything today.
But at any rate they were mostly only red, less commonly green, orange or yellow back then and although we did see some attempts to produce higher power lights back then for a wider range of applications, yellow was not that attractive a colour for a lot of purposes and LEDs still did not get a wider application. It is about 50 years since these early LEDs came into widespread use around 1970. However, it was around that time that the first blue LED was designed and prototyped but it took further development in the 1990s before they were available at reasonable cost and brightness. This meant for the first time it was possible to combine red, green and blue emitters together to produce white light, and therefore the development of LED lamps for domestic lighting applications became possible for the first time. With further improvements both in brightness and cost, LED lamps have now become a cost effective alternative to compact fluorescent and incandescent bulbs in the home with the ability to achieve significant power savings over the older types of lamp.
My recollection is the Philips and other brands of LED light bulb becoming available in our supermarkets about 5-6 years ago but it may be more recent than that. I needed little incentive to replace all the bulbs in my house with these devices, but it was obvious then that Philips were dumping old stock of obsolete products into the NZ market as their bulbs were significantly bulkier than Panasonic product available from a different retail chain. Over time the next generation product became available with the 100W equivalent lamps becoming the size of a traditional incandescent, an important consideration for some types of enclosed fittings where larger bulbs would not fit. I used a Panasonic bulb in an outside light at home because the Philips offering was much too large. My early choice of product was warm white around 3000K colour temperature but later on I decided to change everything to cool daylight or 6000 – 6500K colour temperature, but still have a pile of the warm daylight bulbs because they last so long. Most common in my house is the 13W type that produce about 1400 lumens, probably second generation of Philips in NZ. Because I haven’t needed to buy more, I don’t have the more efficient current generation (3rd?) that are typically in the supermarkets at the moment, an example being 12 W 1360 lumens. But in fact the current range of product internationally (4th gen?) has efficiency around 130 lumens per watt rather than the 110-115 lm/W we are seeing with what we can buy through the standard retail chains in NZ.
Special applications can require bulbs at the low or high end of power and I have evaluated both, the lowest size of bulb typically available here in regular cap sizes (E27 edison screw or B22 bayonet cap) being around 4W and the largest currently around 30W. But again, Philips ensures we only get the old obsolete products; I have here three recent purchases, being a 4W 250 lm B22, a 19W 2300 lm B22 and a 30W 2800 lm B22. You can see with a little effort of calculation that the efficiencies of these products vary between 63 to 121 lm/W, which is all well below the current production internationally, especially that 4W bulb at only 63 lm/W and the 30W lamp at 93 lm/W. The 19W light was the most efficient at 121 lm/W, and the current Philips range includes a 26 W high power lamp producing 3000 lm which is 115 lm/W, much better than the 30W available in NZ, whereas the newest models listed on their website top 130 lm/W. Given that supermarkets currently have a 6W 580 lm bulb from Philips there is really no excuse for such an inefficient 4W bulb being retailed at a well known hardware chain, or the 30W bulb at the high power end of the range. However with the dominance that Philips have both in terms of the retail market, and the production of higher efficiency and higher power LED bulbs generally, there is little incentive for them to bring the more efficient models into NZ as long as they can dump the older products into the local market.
If you are looking for higher power bulbs in particular then take a look at Bunnings’ product range as they have Osram bulbs up to 45W / 4500 lm which are slightly more efficient than what Philips have and therefore will save a little power at the higher end of the output range. I am using the 30W / 2800 lm Philips cool daylight bulb in one room of my house and I also have one of the 19W / 2300 lumen bulbs as well as several 18W / 2000 lm bulbs around the place. I also have three SceneSwitch bulbs that provide three levels of brightness in use also. At the low power end of the range, there is slightly more choice in ES cap bulbs than BC, if your fittings can accommodate the former, and for really low outputs, smaller form ES fittings which can be obtained, will take smaller LED bulbs, but mostly round my place I am sticking with standard fittings with LED bulbs around 250 lm, typically about 4W. As a general rule 10 lm is about the same as 1W incandescent, which makes an average LED bulb around 10x more efficient than incandescent lamps.