It’s important to emphasize that this is a laboratory result—this level of performance is not yet available in Cree’s production LEDs, as the company’s press release points out. However, history shows that the advanced technology behind such R&D results usually transitions into production LEDs after a certain period.
The Cree LED produced 197 lumens of light output and achieved 186 lm/W efficacy at a correlated color temperature of 4577K. The tests were conducted under standard LED test conditions at a drive current of 350mA, at room temperature.
Cree also told LEDs Magazine that the CRI was not measured, and that the device contained an XLamp XP-G size chip measuring 1.4 x 1.4 mm (i.e. 2 mm2 ). The chip size is important when trying to compare results, since a larger chip at the same current has lower current density, which should lead to enhanced performance.
Making “apples-to-apples” comparisons with other companies is tricky (see Related Stories, but this should not detract from the impressive nature of Cree’s numbers. “This result is a testament to the tremendous progress Cree has made this year,” said John Edmond, Cree co-founder and director of advanced optoelectronics.
“As energy efficiency becomes increasingly important in addressing our nation’s energy challenges, Cree is doing its best to deliver the most energy-efficient LED technology possible.”
Cree and Liaoyuan Lighting show 98.3 lm/W LED streetlight
Cree and Ningbo Liaoyuan Lighting Co. hosted the 2009 LED Lighting Fixture Promotion Conference last week in Guangzhou, China. The conference featured government officials and leaders from city street lamp management offices.
Liaoyuan Lighting and Cree jointly exhibited several lighting products based on Cree’s LED technology, including street lamps featuring Cree’s brightest and most efficient XLamp® XP-G LED components. This is the first time that Liaoyuan Lighting used Cree XLamp XP-G LEDs in a light fixture.
The XLamp XP-G LED delivers up to 132 lm/W component efficiency, and enabled Liaoyuan Lighting to create a street lamp system efficacy of 98.3 lm/W in a 150-Watt product. Liaoyuan Lighting is planning volume production of these 150-Watt street lamps to address the lighting needs of more Chinese cities.
Liaoyuan Lighting also demonstrated a 300-Watt street lamp that uses Cree XLamp XP-E LEDs. These lights are installed on Southern Guangzhou Avenue, a key 10-lane thoroughfare in downtown Guangzhou. The Liaoyuan streetlights demonstrate increased luminance and uniformity compared to the prior high-pressure sodium lights. Additionally, Guangzhou is reporting energy savings of more than 40 percent over the old high-pressure sodium lights, as well as better light quality.
Lin Zhengang, engineer of the Guangzhou Streetlamp Management Office said, “Energy-saving products are becoming increasingly popular in the current economy. The LED street lamps we installed enable us to not only enjoy beautiful light, but help us better meet our energy-efficiency and environmental protection goals. With the government’s ever-growing demands for energy-efficiency and clean technology, we expect that such products will be widely used in our urban facilities.”
Shao Yunwei, general manager of Liaoyuan Lighting said, “We are very happy to see a growing market demand for high-efficiency street lamps. Working with Cree, we plan to continue our efforts to produce more environmentally-friendly and more efficient LED lighting products.”
Tang Guoqing, general manager for Cree China Sales, explained, “We are very happy to see Liaoyuan Lighting announce such remarkable achievements using Cree LED technology. We anticipate more and more energy-saving and environmental lighting products will be installed on streets throughout China. Cree has long made efforts to push the development of LED lighting, and continues to bring its latest products and technological advancements to the citizens of China.”