Use of efficient lighting technology:-

• Replacing conventional 40 watt tube lights by more efficient tri-phospher coated tube lights like Lumi-lux by Osram or True-light by Philips should be used. These tube lights have efficacy of more than 90 lumens/watt as compared to 65-70 lumens/watt of the existing tube lights.
• If possible, evaluate a chance of having a separate lighting feeder working at a lower supply voltage.
• Replacing the conventional magnetic chokes either by low loss chokes or electronic ballast can reduce the ballast losses from 10-12 watts to 3-7 watts. Before selecting the electronic ballast, factors like effect of harmonics, ability of ballast to suppress harmonics or surges & ability of twin tube ballast to work with single tube lights should be considered.
• Replacing incandescent bulbs either by Compact Fluorescent Lamps or by normal tube lights can result in attractive savings with payback periods of less than 1 year. As a thumb rule one can replace 40 watt bulb by 11 watt CFL, 60 watt bulb by 15 watt CFL & 100 watt bulb by 18/25 watt CFL.
• While replacing bulbs with CFLs one thing should be kept in mind that, CFLs can not replace the fluorescent tubes directly. Although CFLs have efficacy (luminous efficiency) lower than tri-phospher coated tubelights, they can result in savings if used to replace tube lights by reducing the mounting height. i.e. by having the CFLs placed closed to working plane