Optronic Laboratories : Light Measurement Experts

According to the report, there were 39.9 million SSL A-lamps (A19 lamps with a legacy Edison base) sold globally in 2011. Strategies Unlimited analyst Katya Evstratyeva said that Japan led the way in consuming LED A-lamps with 24.7 million of the global total. The Japanese?Eco-point program?was in part responsible for the high market numbers, but Evstratyeva said other factors such as environmental concerns and high prices in compact-fluorescent lamps (CFLs) contributed as well.

Linear lamps

Perhaps surprisingly, the market for LED-based linear fluorescent replacement lamps was strong globally as well. Strategies Unlimited reports 19.3 million units sold with 41% of those sales coming in China, 21% in Japan, and only 18% combined in the US and the European Union.

Evstratyeva noted that an obstacle to more linear lamp sales is the?DOE testing?that has documented lower light output for LED-based replacements relative to fluorescent lamps. Evstratyeva said, “LED-tube-retrofit projects are taking place only when project owners are willing to forego the light output for the sake of energy savings.”

China is a perfect example of a case where energy savings drove sales said Evstratyeva. Rising electricity rates and longer working hours in commercial and industrial applications make energy efficiency a top concern.

We at?LEDs Magazine?have seen an uptick in use of linear LED lamps of late that indicates newer products are closing the gap in terms of light output. Recent projects at?Pasadena City College, a?San Diego restaurant called Hodad’s, and an?Air New Zealand facility?all were bullish on the technology.

Price declines

The Strategies Unlimited report does temper the positive across the retrofit lamp market with some concerns. The firm is forecasting a 14% annual decline in the average selling price of LED-based lamps. That price drop can help spur growth but reduces the total sales numbers and in some cases profit margin.

The firm noted that an oversupply of LEDs could continue to benefit lamp manufacturers targeting lower prices. But most of that oversupply is in backlighting LEDs, and those components aren’t ideal for general-illumination products, although some manufacturers are using them in low-cost, low-light-output products.

Matching test to luminaire

As Alex Baker, Energy Star lighting program manager, outlined in a recent presentation at LEDucation in March, whether a luminaire is directional or non-directional determines how it is going to be tested. For instance, directional luminaires are typically functional luminaires such as down lights, accent lights and under-cabinet lights. Such products are tested using luminaire photometry according to the IES LM-79, including fixture optical losses (i.e., luminaire lm/W).

Non-directional or decorative luminaires such as wall sconces, chandeliers and bath vanities are photometrically tested according to the newly published IES LM-82, determining such metrics as the source efficacy in lm/W. LM-82, the IES-approved method for ?Characterization of LED Light Engines and LED Lamps for Electrical and Photometric Properties as a Function of Temperature,? is designed to assist luminaire manufacturers in selecting LED light engines and integrated LED lamps for their products, particularly decorative luminaires like chandeliers which cannot be easily measured with LM-79. Baker stated that to date, Energy Star has qualified over 1000 luminaires.

Readers of?LEDs Magazine?will recall that the EPA?postponed the effective date for the Luminaires specification?from October 1, 2011 to April 1, 2012 in order to allow Energy Star manufacturing partners and EPA-recognized certification bodies and laboratories the necessary time to appropriately apply the technical requirements contained in the new specification, while in the interim maintaining a sufficient selection of Energy Star qualified fixtures for consumers. The new spec can be downloaded atwww.energystar.gov/index.cfm?c=new_specs.luminaires.

Energy Star streamlines testing

The new specification is essentially designed to streamline the testing process for luminaires. For instance, the sample size required for photometric testing of directional luminaires has been reduced from three units to one. A minimum of one sample instead of three is likewise required for the in-situ temperature test for lumen maintenance of solid-state lighting (SSL) products. The spec also reduces sample-size requirements for LM-80 lumen maintenance testing to be consistent with the recommendation made by the TM-21 working group. TM-21 allows the long-term?lumen maintenance projection of LED sources?using LM-80 data.

Other changes to the Luminaires specification include an expansion of the allowable mounting variations for outdoor luminaires. The spec has added a directional fixture type for ventilation fans with a down light. Finally, minor adjustments have been made to the methods of measurement and reference documents regarding testing requirements for off-state power consumption and solid-state electromagnetic and radio interference to avoid unnecessary test burden.

Next steps

According to Baker, the EPA is currently working on Draft 2 of the Energy Star Lamps V1.0 specification, which is expected to be finalized this year and will go into effect in 2013. Like the Luminaires specification, the Lamps spec combines two other specifications, the Integral LED Lamps (V1.4) and Compact Fluorescent Lamps (V4.3) specifications.

Brodrick noted that there is still no agreed-upon way to measure or report lifetime for solid-state lighting (SSL) products. However, in recognition of the purchaser?s need to know an expected life for an SSL product, the DOE arrived at the use of LED lumen maintenance, consistent with TM-21 and based on LM-80 measurements, as an indicator of product stability.The decision was made not to use lumen maintenance in terms of L70, the point at which light output falls below 70 percent of initial levels, because the results may be misinterpreted as lifetime values. Instead, the metric will identify the remaining useful percentage of initial output projected to be reached any of three fixed points in time, after 25,000, 15,000 or 10,000 hours, which the manufacturer can select.

Regarding the warranty, the manufacturer can choose to list ?yes? if a warranty is available. The DOE has indicated that listing a number of years associated with the warranty could also be misleading because different components in the product could be covered for different periods. For products with a “yes” designation for warranty, LED Lighting Facts has added the ability to link to the manufacturer’s warranty directly from the products list.

The two new listings are optional. To date, over 4750 products are carrying the DOE?s Lighting Facts label.

It is important to differentiate the DOE Lighting Facts label from the FTC Lighting Facts label. The latter has been required on all medium screw-based bulbs sold to consumers since January 1, 2012. That label lists light output (lm), required power (W), appearance (CCT), presence of mercury, a lifetime estimate in years (based on 3 hours of usage per day) and energy cost ($/yr based on 3 hr/day, $.11/kWh).

UV lamp market 2011-2016

The annual market for ultraviolet (UV) LEDs will grow by a factor of five over the next few years, reaching $150?million by 2016 ? according to the France-based technology market analyst company?Yole D?veloppement.

Pars Mukish, LED and compound semiconductors analyst at Yole, believes the UV-LED market to have been worth only $32.5?million in 2011, accounting for just 10% of the wider market for UV lamps.

But with industry consolidation and the arrival of a number of Asian companies now targeting the near-UV (UVA and UVB) wavelength ranges, Mukish expects the increased competition to prompt falling prices and much wider adoption of the technology.

At the same time, developments in LEDs operating at much shorter UVC wavelengths (below 300?nm) are beginning to transfer out of the laboratory, for what could be widespread application in air and water purification. As a result, by 2016 UV LEDs are expected to triple their share of the UV lamp market to 28%.

Mukish said: ?At the device level, Asian companies, especially Japanese and Taiwanese ones, have taken the lead on the UV LED market, but recently some Chinese companies have also entered. This should increase competition, reduce prices and enable mass applications in the medium-to-long term.?

Near-UV applications dominate
LEDs emitting in the UVA wavelength range make up the largest chunk of the overall UV LED market, thanks largely to industrial UV curing applications. In Yole?s market report on the same topic a year ago, the analyst highlighted Heraeus Noble Light and Phoseon as two of the major players in the emerging market for UV LED curing lamps.

But this year has seen the formation of two professional associations dedicated to UV LED curing, says Yole, indicating that the technology is becoming much more widely accepted. Recent increases to UV LED output power should lead to cheaper lamps, while applications in counterfeit detection and photocatalyst air purification should also continue to grow.

In the UVC range, where the shorter wavelengths can be used for direct water and air purification, developments are at a much earlier stage. That is largely because it is far more difficult to manufacture LED chips emitting at wavelengths below 300?nm, while the availability of aluminum nitride (AlN) substrates on which the chips can be produced is very limited.

In earlier reports, Yole had predicted that high-volume applications of UVC emitters would begin to take hold in 2010. However, that has not happened, and with efficiency, lifetime and cost challenges remaining, the analyst firm now predicts that widespread adoption will only begin in 2014.

Aquionics’ “UV Pearl”

Signs of a commercial UVC LED market
But there are initial signs of a commercial market developing around this shorter wavelength. In early May, the Halma subsidiary and UV disinfection specialistAquionics?is due to launch its first germicidal UV LED product, the ?UVPearl?, at the Interphex 2012 trade show in New York.

Aquionics is partnering with Charlotte, North Carolina, firm?Dot Metrics, which has developed UV LED technology with optimized UVC output. Another company in the Carolinas, Columbia-based?Sensor Electronic Technology (SETi), is in the process of expanding its UV LED manufacturing operation after a $20?million injection of capital last October.

SETi said at the time that it was witnessing greater market pull for the LEDs to be used in disinfection and personal healthcare, and purchased a new facility for volume chip production, with the potential for expanding the site to 130,000?square feet. Just last week, SETi said that it had received the AS9100 international aerospace industry certification for its operations ? suggesting that applications in aviation, space and defense could also be emerging.

In another significant recent development, the Rensselaer Polytechnic Institute spin-off Crystal IS was bought out by the Japanese industrial giant Asahi Kasei in January this year, with a view to accelerating the commercialization of its UVC-emitting LEDs.

Crystal IS was initially a materials-focused company, and specialized in AlN substrates, but since switching that focus to LEDs it has delivered some impressive research results, including a record-breaking 9.2?mW output power at the key germicidal wavelength of 260?nm last year.

Though AlN-based UVC devices could ultimately drive the largest market for UV LEDs, advances in the AlN substrate material will be needed to bring down the cost of the technology to an acceptable level. Yole says that several companies are looking to commercialize 2-inch bulk AlN wafers by the end of this year, and if that does prove to be correct then commercial device applications could follow soon after.

Yole’s latest UV LED market report is available now via the company’s?web site.