Great Arithmetic From Parish Schools Lighting Upgrade


Terrebonne Parish Schools needed better light. What they got from a comprehensive lighting upgrade was much better light and important energy and cost savings. How important, in these times of soaring energy costs? It adds up to 42 percent savings in energy for lighting, with the “extra credit” advantages of sharply lower maintenance costs and improved lighting that meets quality objectives and Louisiana classroom brightness requirements.


Terrebonne Parish School District is comprised of 42 schools and three administrative facilities. They house a broad range of daytime and evening activities with the lighting and security demands of a typical active campus of assembly areas, cafeterias, gymnasiums, corridors, administrative offices and, of course, classrooms.


Siemens Building Technology Landis Division recognized the opportunities for energy/operational savings and lighting upgrade improvement in the mix of facilities, some more than 20 years old, with several buildings as old as 80 years. Siemens approached the school district with a performance contract that pays for the comprehensive energy savings project through the savings it generates. In the world of savings projects, lighting retrofits are one of the least expensive, quickest to accomplish, and offer a rapid payback. And, they do so much more than just save money-they improve the quality of light for students and staff.


As part of an overall plan to reduce energy consumption, Southern Energy Technologies, Inc. an energy services company, was contracted by Siemens to perform the lighting system upgrade work. Begun in August 1998, the Siemens/Southern Energy plan for Terrebonne Parish called for the project to be accomplished in seven phases and completed by September 1999.


As in all lighting in their projects, the team has three main objectives:





The lighting systems comprised a broad range of fluorescent and incandescent fixture types and light sources. A majority of these fixtures were fluorescent, ranging in age from 10 to 40 years. While they were generally kept in decent working order, they were, nevertheless, old and inefficient by today’s standards. The overall lighting levels in these facilities varied from too high to well below standard, some as low as 10 foot-candles. The State of Louisiana’s Department of Health requires a minimum of 50 Foot-candles (a Measurement of brightness) illumination on the desktops and a Visual Comfort Probability (VCP) of 70. (VCP is a system for measuring the impact of glare).


The scope of the project in each building was to retrofit existing lighting, delete or add new lighting (to comply with Louisiana state regulations), and standardize materials and components that must be maintained and inventoried.


Each facility was audited to determine two baseline costs and condition of the lighting system and establish the pattern of energy usage for that system and building. Every building had its own mix of fixture types, many consisting of fluorescent fixtures and magnetic ballasts with less efficient F40 and F96T12 lamps. The lighting ballasts in many of the fluorescent fixtures in certain older facilities contained toxic PCB’s and fluorescent tubes contained mercury. These products were properly disposed of in accordance with environmental regulations.


The team’s objectives were met by first establishing where additional lighting was required and where to eliminate wasteful “over-lighting” based upon room types and tasks performed. To maximize lighting efficiency, Southern Energy retrofitted all salvageable fixtures with a mix of low wattage, high lumen and standard electronic ballasts, and installed new fluorescent T-8 lamps that have an environmentally friendlier low-mercury content.


Eight-foot fixtures were replaced with 4-foot fixtures or retrofitted to accept 4-foot tubes to lend uniformity to the job and reduce the number of different types of lamps and ballasts that have to be kept on hand for maintenance purposes. Also, the new 4-foot T-8 lamps have longer service life and maintain their lumen output better over the course of that life than the replaced 8-foot T12 lamps.


Over 3,170 deteriorated, inefficient, and or obsolete fixtures were replaced, together with 2,062 new diffusers and lens to improve lighting quality and, maintain VCP rating in classrooms. Incandescent lighting was replaced with 1,149 new compact fluorescent lamps and/or replaced with new fluorescent lighting fixtures to increase lighting levels and reduce maintenance costs. About 746 incandescent exit sign were replaced with new light emitting diode (LED) exit signs that consume only 2 watts per fixture rather than 40 watts, a significant savings in signs that are lighted at all times.


In total, Southern Energy upgraded 26,241 existing lighting fixtures throughout the district with a combination of the following equipment:



The resulting savings are substantial. The project reduced electrical demand by 18,504 kilowatts per year and electrical usage by 4,518,878-kilowatt hours per year. It netted the district $ 290,000 per year in energy savings, a simple payback of 63 months with a ROI of 19 percent and $ 90,000 per year in avoided maintenance cost. The lighting level at the desktop is increased to meet or exceed the 50foot-candles the State requires and the energy expended for lighting is reduced by 42 percent.


The environment benefited also, with the elimination from the air of 6,926 tons of carbon dioxide, 22.44 tons of nitrogen oxide, and 19.75 tons of sulfur dioxide, based on formulas from the U. S. Environmental Protection Agency. And, 17,617 ballasts containing toxic PCB’s were removed and incinerated, and 55,320 T12 fluorescent lamps containing mercury recycled.


This was an “a-plus” project for the schools, students and staff, taxpayers and the environment-with high marks for the Siemens/Southern Energy/Terrebonne Schools team.