LED industry lays standards foundation
LED-based lighting manufacturers now have an authoritative basis to use when comparing rival products, thanks to a core framework of testing guidelines that will soon be complete.
“The object of standards is to align all interests, so that everybody has a good experience.”The first three finished US specifications, which cover definitions and testing for products in areas including light output and chromaticity, will be joined by a fourth LED longevity testing standard in upcoming weeks.
The Illuminating Engineering Society of North America (IESNA) and the American National Standards Institute (ANSI) are serving as publishers, but the solid-state lighting (SSL) industry is playing a driving role.
LED and lighting fixture maker Cree is one such participant. The company s director of new business development, Mark McClear, told compoundsemiconductor.net that the standards are already having an impact on its chip-making operations.
“Every one of these standards has ripple effects - both backward into the manufacturing of the LEDs, and forward into the consumer experience,” said McClear. “The object of standards is to align all of those interests, so that everybody has a good experience.”
“These four get us to a point where we can offer credible luminaires in the marketplace.”
ANSI published the C78.377-2008 specification for chromaticity ranges of SSL products on February 15. It also approved an addendum to its RP-16-05 nomenclature standard that precisely defines the levels of complexity of solid state lighting products on May 8.
“Cree has already switched its LED bins to support the chromaticity standard,” McClear said. “If luminaires in the market are going to be tested to this standard it doesn't make sense to sell LEDs that are outside of it.”
IESNA s LM-79 standard "“ also published in May "“ regulates methods for testing SSL s light output, efficiency and chromaticity. IESNA is also responsible for the pending LM-80 standard, which will cover testing for depreciation in the lumen light output of packaged LEDs.
That data can then be converted into a luminaire lifetime by use of an approved model, meaning the manufacturer of the packaged LED chip bears significant responsibility.
“We ve got thousands on test, and they're in all different types of environment,” explained McClear. “We've got rows and rows of environmental chambers and they all had to be modified so that we can be testing to the LM-80 standard.”
Get with the program
Although there is agreement at the standards level, attempts to use these standards as the basis for an Energy Star program are proving somewhat more controversial. The program is synonymous with energy-efficient home appliances and will allow luminaires to be labeled with the “Energy Star” logo if they meet its performance criteria.
Energy Star in the US is nominally a collaboration between the Department of Energy (DOE) and the Environmental Protection Agency (EPA), but the two sides want different definitions for the Energy Star for SSL.
In the words of Jim Brodrick, who leads the DOE SSL program, “DOE has worked very diligently with industry to chart a technically rigorous and market-appropriate path that would lead to a strong SSL market.”
“EPA, in essence, has bypassed this type of process by rushing out criteria that lack the technical requirements that would prevent the qualification of dim, bluish light products that we know will "˜turn off' consumers.”
When McClear spoke to compoundsemiconductor.net, he was just preparing to fly to a meeting with the DOE about this very dispute.
“EPA and DOE part company over the usage of LM-79,” McClear explained. “The EPA has got a different method that they're trying to propose, that comes out of a group at Rensselaer Polytechnic.”
“There definitely has to be a harmonization between the DOE and the EPA programs - and they will be harmonized.”
