What is an LED?

LED is the common abbreviation for a light-emitting diode. Each individual LED consists of a semiconductor diode that emits light when a voltage is applied to it. The electronics industry has used LED technology for several decades as indicator lights for various electronic devices. In more recent years, LED technology has progressed to the point where it is viable for general lighting applications. Please check the following website for more information.

Where have LEDs been used in the lighting industry?

LEDs began to be used in the lighting industry in the late 1990’s typically in aesthetic, effect, or specialty lighting applications, including architectural highlighting. The use of LED luminaires in applications such as street lighting, area lighting, parking structures, security lighting, and even general lighting for interior spaces is viable today both economically and from an illumination performance standpoint.

Why does the identical LED chip package lumen depreciate
at different rates from manufacturer to manufacturer?

Unlike previous technologies, LED manufacturers have a much greater impact on the rate of lumen depreciation based on their luminaire designs. Thermal design plays a critical role in the rate of lumen depreciation. Therefore you should see variation in lumen depreciation from manufacturer to manufacturer, as well as within different product families offered by the same manufacturer.

What's the difference between efficiency and efficacy?

Lighting fixture efficiency is the ratio of the total lumens exiting the fixture to the total lumens initially produced by the light source. For example, if a bare 100W incandescent lamp (light bulb) produces 1,000 lumens, and it is put into a lamp fixture that delivers 700 lumens, this would be an example of a 70% efficient fixture.
Efficacy is a term normally used in cases where the input and output units differ. In lighting, we are concerned with the amount of light (in lumens) produced by a certain amount of electricity (in watts). Efficacy = Lumens Per Watt

Why are LEDs considered a GREEN technology?

LEDs are environmentally friendly on many fronts. First, unlike HID (High Intensity Discharge) lamps LEDs contain NO mercury. In addition, some LED luminaires are RoHS (Restriction of Hazardous Substances) compliant and have been designed to provide more than a decade of near maintenance-free service. That means no re-lamping which means no waste.
Assuming an HID fixture is re-lamped every two years, that’s five re-lamping cycles over a 10 year period.  Just imagine the benefits of choosing LED:
•    No concern over proper disposal (hopefully not simply thrown in a landfill) of old HID lamps containing harmful mercury.
•    No fuel used and the accompanying pollution to service those fixtures.
•    Greatly reduced potential for lane closures and other productivity and inconvenience-related costs associated with maintaining an HID system.
•    No natural resources lost to produce the replacement lamps that contain mercury.
•    No fuel used to move old-technology lamps from the factory (most likely overseas), to the distributor, to the contractor, to the job site.
It’s important to keep in mind all the positive and powerful ripple effects that using LED technology can have on the environment.

How are LEDs able to outperform HID?

Super-bright white LEDs have the advantage of minimal lumen depreciation, better optical efficiency and high lumens per watt. LEDs also have a vastly longer life span than traditional lamp sources. The luminaire must be designed to leverage these inherent advantages of LEDs. A Total Systems Approach is needed for an LED product to bring all these features together.

BetaLED luminaires also have an environmental advantage in that they contain no mercury, are RoHS compliant, last longer and produce less waste. In fact, 20 to 25% (by weight) of the product is made using post-consumer recycled materials (aluminum castings and extrusions). Furthermore, 70% (by weight) of BetaLED fixtures are readily recyclable. The remaining LED circuit boards, drivers, wires and connectors are all non-hazardous, mercury-free, and RoHS compliant.

If an LED fixture has lower initial lumen output than a traditional HID light,
how can LED claim to deliver lumens more efficiently than HID?

When you average delivered lumens over the course of 60,000 hours, you’ll see that LED outperforms a 400-watt MH lamp operated in a horizontal position. (60,000 hours is used for this comparison to show three full life cycles of the HID.)

The MH’s lumen depreciation, as well as optical and ballast losses, quickly reduce output of the HID system. Note that there are three relamps over 60,000 hours.

Conversely, LED has significantly better lumen maintenance and a more efficient driver. Also note that the LED fixture typically doesn’t need relamping from zero to 60,000 hours.

Combine this with Beta’s exclusive NanoOptic and LED outperforms MH over the course of the life of the fixture.

Result: the LED’s average delivered lumens is 74% higher than HID over 60,000 hours.