Has the 60W GLS met its match? | Hardware | Lighting.
LED replacements for incandescent lamps are not new – they’ve been around for a few years – but Cree reckons users will find the light from its TrueWhite Light indistinguishable from that of a 60W GLS. Richard Simmonds investigates
Announcing a new technology with the line “thank you Mr Edison, we’ll take it from here” might sound like the height of hubris. But when the claim comes from an LED manufacturer of Cree’s pedigree, people may be less willing to dismiss what they have to say.
Cree made its bold claim as it demonstrated a prototype LED retrofit lamp, TrueWhite Light, that it says is the closest equivalent to a standard 60W GLS lamp yet devised.
Uniquely, it says, it has been designed to meet US Energy Star requirements for products equivalent to 60W lamps.
“This is a significant milestone for the industry,” says Chuck Swoboda, Cree’s chairman and chief executive officer. “In the race to commercialise low-cost, energy-efficient LED bulbs, the industry has forgotten that LED lighting is supposed to look as good as the technology it is replacing. This is the first no-compromise replacement for a 60W incandescent bulb.”
Facts and figureslighting.co.uk
The prototype lamp that Cree demonstrated last month has an output of 800 lumens. Input power is less than 10W, colour temperature is 27ooK and its colour rendering index is greater than 90. It can also be dimmed to 5 per cent of full output. Fins around the base cool the lamp. Cree’s vice-president of technology, Rob Glass, says: “This is the first standard LED A-lamp that combines high output with very high efficiency, in a small form factor, without the additional cost and complexity of active cooling or other design compromises.”
“The industry has forgotten that LED lighting is supposed to look as good as the technology it is replacing” Chuck Swoboda, Cree
However, there are several other products on the market that appear to measure up to TrueWhite Light. Philips introduced its first LED retrofit lamp at Light + Building in April 2008, and last year launched its 12W EnduraLED lamp at Lightfair International. It too was designed to replace the 60W incandescent. Osram Sylvania was also at Lightfair, and unveiled a 60W replacement lamp in the form of the Sylvania Ultra LED lamp, which president and CEO Rick Leaman described as “the first 60W replacement on the market to offer energy savings without compromise”.
Form and function
So what is it that Cree has done that Philips, Osram and others like them have not?
According to Greg Merritt, vice-president of corporate marketing: “It is important to bring high-quality standard LED bulbs to market – those that look, feel and perform as well as, or better than the technologies they are replacing.”
Cree says that no commercially available LED A-lamps meet the Energy Star performance criteria for 60W standard replacement lamps “at this level of efficiency and light quality”. A specific requirement is for lumen maintenance to L70 after 25,000 hours – that is, lumen output should be 70 per cent after that time.
Testing, testing
The jury is still out on TrueWhite Light’s lumen maintenance performance. Cree has submitted a TrueWhite Light prototype to a third-party laboratory for testing, and the company is confident it will pass with flying colours.
“This demonstration lamp can meet Energy Star criteria for standard 60W LED replacement bulbs,” says Merritt.
Another area where Cree may be pulling ahead of the pack is in TrueWhite Light’s photometric characteristics.
The prototype’s light engine, optics and patented remote phosphor technology are designed to create a uniform photometric distribution between 0 and 135 degrees – an omni-directional light pattern which is similar to that of an incandescent lamp.
Solid foundations
So TrueWhite Light has solid technical foundations, but what is its business aim? Merritt says: “The purpose of the TrueWhite Light is to demonstrate the kind of A-lamp performance possible using currently available technology. It is a prototype and a technology demonstration.”
However, he adds: “We haven’t made any decisions as to if, how or when to bring this prototype or the underlying technology to market.” The company would not be drawn on whether it would start manufacturing LED retrofit lamps, or license its technology to others.
Cree revealed TrueWhite Light on the 131st anniversary of the date Thomas Edison was granted a US patent for his incandescent lamp, proclaiming: “Today’s LED lighting revolution heralds the demise of Edison’s 1880, horse-and-buggy-era invention.”
We’ll have a clearer idea of what Cree has achieved when the third-party test results are published, but the company remains confident that it has devised the best LED-based replacement for one of the most popular incandescent light sources.
HALF A DOZEN INNOVATIONS
This cutaway shows the guts of the prototype TrueWhite Light that Cree demonstrated last month. The light engine is based on Cree XLamp LEDs, and the appearance of remote phosphor technology is no surprise.
Cree holds more than a dozen remote phosphor patents.
1 Diffuser globe
2 Cree LED light engine
3 Heatsink for passive cooling
4 Remote phosphor globe
5 Dimmable power supply and drive circuit
6 Standard E26 lamp base