Industry News




 

04/24/2013

New LED Lamps Light Street, Not Sky

 
New LED streetlamps focus on lighting specific areas so that nothing goes to waste.  Will these energy savers become the norm?

Let this stat sink in: 98% of lamp's energy goes to lighting the street instead of the night sky

Streetlights illuminate the night, shining upon roadways and sidewalks across the world, but these ubiquitous elements of the urban environment are notoriously inefficient and major contributors to light pollution that washes out the night sky. Recent innovations in light emitting diodes (LEDs) have improved the energy efficiency of streetlights, but, until now, their glow still wastefully radiated beyond the intended area.

A team of researchers from Taiwan and Mexico has developed a new lighting system design that harnesses high-efficiency LEDs and ensures they shine only where they're needed, sparing surrounding homes and the evening sky from unwanted illumination. The team reported their findings today in the Optical Society's (OSA) open-access journal Optics Express.

A unique feature of the new LED system is its adaptability to different street lamp layouts, "to all kinds of streets and roads, providing a uniform illumination with high energy efficiency," says co-author Ching-Cherng Sun of National Central University in Taiwan. For example, some modern lamps that line a thoroughfare or suburban sidewalk lean into the middle of the road, lighting the street from above.

But more often, lamps are posted to one side of a street, or alternating in a "zig-zag" pattern from one side to the other – a layout that may be more efficient for roads with high traffic flow. The new design provides flexibility to be used for different illumination requests while maintaining a high efficiency, Sun says.

The proposed lamp is based on a novel three-part lighting fixture. The first part contains a cluster of LEDs, each of which is fitted with a special lens, called a Total Internal Reflection (TIR) lens, that focuses the light so the rays are parallel to one another instead of intersecting—a process called collimation. These lens-covered LEDs are mounted inside a reflecting cavity, which "recycles" the light and ensures that as much of it as possible is used to illuminate the target.

Finally, as the light leaves the lamp it passes through a diffuser or filter that cuts down on unwanted glare. The combination of collimation and filtering also allows researchers to control the beam's shape: the present design yields a rectangular light pattern ideally suited for street lighting, the researchers say.

The team tested their design's performance by analyzing how little the beam would spread as it hit its target—a road or sidewalk 10 meters or more away from the source of the light. They quantified the lamp's performance using something called optical utilization factor (OUF), a number that describes the relationship between the flow rate of light at the target and the flow rate of light coming directly out of the LEDs.

Higher OUF indicates better performance. Simulations show that the new design achieves an OUF of 51 to 81 percent, greatly outperforming a recent "excellent" design that reached 45 percent. Furthermore, the proposed streetlamp meets high expectations for power and brightness. And light pollution is also significantly reduced: for conventional street lamps, up to a fifth of their total energy is directed horizontally or upward into the sky. The best LED streetlamps reduce this to a tenth of their total energy. In the new model, just 2 percent of the lamp's total energy would contribute to light pollution.

In addition to cutting light pollution and glare, the new model could also save energy. "A general LED street light could reduce power consumption by 40 to 60 percent," Sun says; the increased efficiency of the proposed design would likely save an additional 10 to 50 percent. Furthermore, he adds, the module would be simple to fabricate, since it comprises just four parts, including a type of LED bulb commonly used in the lighting industry.

Sun's team expects to finish a prototype of their design in the next 3 to 6 months, and to begin practical installations of the new street lamp as early as next year.

 


Visit our website today to learn about the design flexibility of a Morton building and the endless possibilities of partnering with our designBUILD team.


Wood construction is both cost and energy efficient. Check out Morton Buildings and our designBUILD team online today to discover all the benefits of post-frame construction.


When choosing a metal-clad building for your next construction project, consider Morton Buildings, Inc., and their designBUILD team, we’ll make your dream a reality.

Yaskawa drives offer quality performance for air handlers and cooling towers on the roof to secondary chilled water pumps in the basement

Bluebeam® Revu® simplifies digital facilities document management from design review to leveraging as-builts, maintenance manuals and O&Ms submittals.

We Can Help You Reduce Energy by 30%

Our mission is to help our customers manage their buildings' energy costs, improve reliability, and enhance performance while having a positive impact on the environment.
CLICK HERE to find out how.


Visit our website today to learn about the design flexibility of a Morton building and the endless possibilities of partnering with our designBUILD team.


Wood construction is both cost and energy efficient. Check out Morton Buildings and our designBUILD team online today to discover all the benefits of post-frame construction.


When choosing a metal-clad building for your next construction project, consider Morton Buildings, Inc., and their designBUILD team, we’ll make your dream a reality.

Yaskawa drives offer quality performance for air handlers and cooling towers on the roof to secondary chilled water pumps in the basement

Bluebeam® Revu® simplifies digital facilities document management from design review to leveraging as-builts, maintenance manuals and O&Ms submittals.

We Can Help You Reduce Energy by 30%

Our mission is to help our customers manage their buildings' energy costs, improve reliability, and enhance performance while having a positive impact on the environment.
CLICK HERE to find out how.


 
07/21/2014

Spaces grow denser as the industry emerges from a slump.

07/18/2014

Study ranks states on fuel and consumption.

07/16/2014

Enhance cleaning practices at your educational facilities.

07/11/2014

Tenants have low tolerance for even one pest sighting, a new survey reveals.

07/10/2014

Battery installations will fuel federal research.

07/03/2014

An ongoing pilot program targets carbon neutrality.

06/27/2014

Potential substitute chemicals boast a low global warming potential.

06/26/2014

Tap into the DOE’s new data stream for renewable energy.

06/23/2014

What to do when the rain stops and the flood recedes.

06/18/2014

Mitigation policies grow in response to changing climate.

06/17/2014

The 2014 World Cup welcomes six LEED-certified arenas.

06/11/2014

An updated study now observes local consequences.

06/06/2014

New survey reveals increasing interest in off-site work.

06/04/2014

Gain ground on sustainability goals.

05/30/2014

With World Environment Day quickly approaching, now is the perfect time for cleaning professionals to think about implementing a green cleaning program or review green products currently in use.

05/28/2014

In 2013, approximately 6.5 million people were employed in the renewable energy industry worldwide.

05/27/2014

Saving money through energy management strategies in Canadian healthcare institutions just got easier.

05/22/2014

A recent study has revealed that the bacteria Legionella, commonly found in fresh water, is able to survive in certain automobile windshield washer fluids.

05/21/2014

Industrial symbiosis is essential to a company’s environmental efforts and can even drive profits.

05/19/2014

Nearly 40 years after Legionnaires’ Disease first gained public attention, the disease remains common throughout the world.

Page 1 of 43
FirstPrevious[1]2345678910NextLast

Sponsored Links