Martin Brown


Georgia Institute of Technology Energy and Sustainability Services


Mike Brown

Date of Site Visit: September 28, 2010

Report Date: December 3, 2010


Conducted by: The Georgia Institute of Technology Enterprise Innovation Institute

Under partial sponsorship from Independent Resolution Services Inc., the

Georgia Environmental Partnership Georgia Department of Natural Resources

Sustainability Division.

The objective of Energy and Sustainability Services is to identify and evaluate, through visits to industrial sites, opportunities for energy conservation and waste minimization. In addition the center conducts evaluations of energy efficient technologies for the purpose of increasing knowledge and improving the implementation of feasible engineering solutions. 

A demonstration of induction lighting was conducted at the City Station parking garage in Morrow, GA. Baseline measurements of fixture power consumption and light intensity in a designated control space with the current 100-watt metal halide fixtures were conducted on September 30, 2010. The metal halide fixtures were replaced with induction during October, and the measurements were redone on November 10, 2010.

With the replacement induction fixtures, the measured light intensity decreased 3.3 percent but the fixture power consumption decreased 43 percent. The test results indicate induction lighting is more efficient in this application.

A second benefit found with induction lighting is increased uniformity of light distribution in the space. Measurements of light intensity in the space evaluated found the ratio of the highest to the lowest as well as the standard deviation to be less for induction lighting. While this is not related to fixture efficiency, it does mean the quality of lighting may be improved by converting to induction fixtures.

Demonstration Planning and Measurement Method

A demonstration of induction lighting for outside applications was initially requested by Independent Resolution Services Inc. and Clayton County Office of Economic Development (OED). The purpose of the demonstration was twofold:

1) show the effectiveness and efficiency of induction lighting for outside applications including street lights, parking garages and architectural lighting for buildings, and


2) assist in the startup of a custom lighting manufacturer (Independent Resolution Services Inc. to be tentatively located within Clayton County.

A meeting was held with Randall Toussaint of the Clayton County OED on February 25, 2010 to discuss his needs and vision for the proposed lighting test. At that time, the plan was to conduct the demonstration at the Olde Towne Morrow development. We visited the site and identified a potential location for the test. The center square of the complex was identified as the most promising demonstration location. This site had approximately 15 decorative lamp-post fixtures placed on the perimeter of an undeveloped square. This site was selected because it was somewhat isolated from other light sources and there were no obstacles to interfere with intensity measurements.

Results, Conclusions

The lighting demonstration of the City Station parking garage provided a valid field comparison between metal halide and induction lighting. While the measured light intensity was slightly less with induction lamps, the input power was reduced by 43 percent. This indicates that the induction lamps are more efficient than the metal halide.

Independent data to support this result is available. Tests at the Rensselaer Tech Lighting Research Center found the efficiency of induction lamps to be approximately 75 lumens per watt. Data for probe-start metal halide lamps were taken from manufacturer’s spec sheets. For a metal halide lamp generating mean light output, the efficiency is about 42.3 lumens per watt. The energy savings from converting from metal halide to induction is the ratio of their respective efficiencies in lumens per watt.

Lamp Initial Lumen Mean Lumen % Initial Mean Lumen/Watt

100 w probe start metal halide 6500 4225 65 42.3

100 w pulse start metal halide 8500 5525 65 55.3

60 w Induction 4778 - - 75

Estimated energy savings = 1 – (42.3/75)

= 43.6%

This agrees closely with the 43% measured savings.

The second result found was the induction fixtures provided more uniform lighting in the space. The maximum-to-minimum intensity and intensity standard deviation is higher for the metal halide lighting. While this is not related to efficiency, uniformity of lighting does provide an improvement in perceived light quality by reducing bright and dark spots. Increased uniformity of lighting may add to the comfort of occupants as they enter an area at night.

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