Last month, Cree announced the development of a 3000K, 3,200-lumen concept luminaire that achieves 200 lumens-per-watt at a CRI of 80 at thermal equilibrium. The prototype, which is AC-powered, is the first 200 lumen-per-watt concept luminaire, the company says, surpassing a benchmark forecast by the Department of Energy and not expected to be surpassed until 2020. The announcement, which follows Philips’ development of a 200 lumen-per-watt prototype replacement lamp last spring, is evidence of continued efforts by lighting manufacturers to produce more efficient LED luminaires for commercial applications. Architectural Lighting spoke with Greg Merritt, Cree’s vice president of marketing for lighting, about how developments such as the company’s new concept lamp are accelerating commercial LED adoption.
 
What type of luminaire is this?
It’s a prototype, so the existing form factor is not designed to be a product. You can best think of it as a linear luminaire for general illumination or for ambient overhead lighting.

Is this an extension or an enhancement of Cree’s 200 lumen-per-watt LED released in December 2012?
We use the same basic technology platform, but we enhanced our SC3 technology, which is the base of our current generation of LEDs. The LEDs in this prototype are beyond the 200 lumen-per-watt LED.

Is the 200 lumen-per-watt output achieved with a 1W LED?
We don’t characterize our LEDs that way. They’re designed to be driven at a range of power levels depending on what the designer is trying to accomplish. This luminaire is 3200 lumens at 16W.

How long was this prototype in development?
About three months. The team leveraged a lot of work that’s been done elsewhere in the company.

Was the prototype shown to lighting designers for feedback?
This is a lab prototype, so it was an exercise for us to push the boundaries on system performance. Designing a complete luminaire has multiple challenges over just designing a piece of one. We have to look at the entire system—the optical engineering, the thermal management, and the AC-to-DC conversion.

So the focus was solely on output?
Yes, but in a complete system. It wasn’t a gimmick to try to game the system to get something we could claim is 200 lumens per watt. We can plug it into an AC outlet and the light comes on.

Were the optics handled to reduce brightness and glare to make this technology marketable?
We didn’t spend a lot of time on managing the optics. We weren’t trying to optimize for any specific application. We were trying to optimize for light extraction.

What are the plans for eventually taking this technology to market?
We’ll identify what application we’re going to address and its characteristics, the levels of optimal control needed, and best form factor. Our focus is accelerating the adoption of LED lighting and the best way to do that is to offer more performance at a lower cost. Every time you take another step up that price–performance continuum, you bring more customers and more applications into the market.

What is the timeline?
Our historical track record is around 18 to 24 months from when we announce a research and development result to when we announce a product at similar levels of performance.

How is industry competition creating a marketable, better-performing LED that will drive eventual commercialization of new technology?
It helps us to identify the gaps in the system. We say, OK, we have high-performance LEDs. What else do we need? We need efficient power supplies, efficient optical delivery systems, and efficient thermal management. Doing a full system requires stressing every single one of those areas.

What are the key challenges to bringing this level of performance to a commercial product?
There’s a high volume availability of high-performance LEDs. Then there’s continued development in optical system design. And a commercial product has to deliver light to the proper target areas. But when we do a prototype, some of that may not be at a cost level that would make sense in a production system. So while we’re pushing the technology, we’re also pushing the cost. You can’t get too far off the curve on high performance and end up with a very high price or it just becomes an interesting exercise.

Of the three challenge areas you mentioned, where is the best opportunity to whittle down the cost to make development headway?
The electrical systems and the optical systems are probably the least mature areas in the business. We’ve been making LEDs for a long time, but people have only been using them in commercial luminaires for the last eight years or so. The more adoption, the more volume—and the more volume, the lower the cost. It’s a combination of inventing new things, which helps to reduce the cost and increase the performance, and building and selling more of them.

This interview has been edited and condensed.

This article has been updated from its original publication to clarify that Cree has updated its SC3 technology.