Sustainable Engineering: More-Efficient Lighting is not Rocket Science

The recent case of a lighting system in a lead-acid battery supplier/recycler shows the kind of energy savings possible without resorting to LELEDs, CFLs, or other superefficient illumination technologies. The battery supplier upgraded the 1970s-era lighting in its 28,000-ft2 facilities using fairly ordinary but modern light systems. For example, 400-W metal halide fixtures in the industrial areas were replaced with 8-ft fixtures containing high-output electronic ballasts and six 4-ft T8 fluorescent lamps at 32 W each.

The upgrade cut power consumption in half while improving light spread and providing an instant start. Power consumption also dropped in the parking-lot areas thanks to replacement of existing 250-W high-pressure sodium fixtures with 175-W metal-halide fixtures, each with an integral photocell to reduce operating hours. Occupancy sensors also went into all possible applications to reduce operating hours. All six-lamp T8 fixtures in industrial areas got motion sensors, conserving energy in portions not in use.

Servidyne Inc., Atlanta, the light designer and contractor for the job, says the economic benefits have been noteworthy. The work was done in less than two weeks, and the energy savings have allowed the battery maker to recoup project costs in just over one year. Moreover, Servidyne secured a rebate from Southern California Edison for the improvement, covering more than half the project cost.