Buying Energy Efficient Fluorescent Tube Light is cost effective.

Lighting represents as much as 25% of our home's electrical use, so it constitutes a significant part of our monthly electricity bill.  Long back, we shifted from the use of incandescent or Tungsten filament bulbs to fluorescent tube lights but it is time that we make an overview of performance of fluorescent Tube Light.   

Performance of a fluorescent tube light is dependent on the performance of ballast and the fixture which is popularly known as choke and starter.  Electronic ballasts are now available.  These type of ballasts consume lesser energy and make tube lights to switch on immediately that is without the starting flicker.  While, energy saving by using an efficient lighting system is directly proportional to the number of hours of use and there are no mandatory requirements to use such equipment's which consume lesser energy, the consumer is the only beneficiary if he uses Energy Efficient products.  The present article tries to prove cost effectiveness of energy efficient lighting options. 

            Tube lights that have been conventionally used and are still in vogue, have tube size of 2' & 4' long with 1" outer diameter.  These are called T8 Tubes.  Energy Efficient Tube Lights have the same length of tube but they are smaller in diameter.  Fluorescent tube lights of 5/8" diameter are called T5 tubes.  We call them Fluorescent Tube Light because the white material used inside the tube is fluorescent material. 

 A typical, conventional T8 tube light consumes about 40 watt power.  An improved T5 tube light consumes only about 28 watt power.  The saving in the use of Electronic ballast is additional.  While, the conventional choke consumes about 13 watt, the Electronic ballast consumes about 2 watt only. Thus the power consumption of a conventional T8 tube light system is of the order of 53 watt whereas the power consumption of Energy Efficient T5 Tube Light System with Electronic choke is about 30 watt only, a saving of almost 40%.  There is thus, an encouraging saving in power consumption if energy efficient tube light is used with Electronic ballast. 

            Another big advantage of Energy Efficient tube light functioning with Electronic ballast is that the power factor of the lighting system is very good.  A good power factor will mean lesser Energy charge if there is KVAH type of metering or there is any power factor levy.   Before disincentives for poor power factor are introduced, it is worthwhile to improve the power factor of the lighting system.  It is quite encouraging that the power factor of a T8 tube light with a conventional choke is 0.59 whereas, the power factor of an efficient T5 tube light with electronic choke is as good as 0.96.  Therefore, Improved lighting system possesses an advantage of improved power factor. 

            Now, we come to cost benefit analysis.  As stated earlier, the conventional tube light consumes 53 watt and the efficient tube light consumes about 30 watt only.  So there is a saving of 23 watts per tube light.  If the burning hours of a tube light is considered as 5 hours only in a daily cycle of 24 hours period, there will be a saving of 23 x 5 = 115 watt hour everyday for each tube light.  This means that in a year of 365 days, the saving of energy per tube light will be 115 x 365 = 41975 watt hours which is equivalent to 41.975 KWH or units.  Thus, about 42 units get saved within a year. Considering an average cost of tariff of Rs. 3.50 per unit, this energy saving is equivalent to Rs. 147/- annually.  The difference in the cost of conventional and efficient tube light is of the order of Rs. 300 only.  Thus, within two years, the extra cost gets recovered and there is continued saving thereafter.  The benefit of extra life associated with efficient tube light coupled with instantaneous switching-on quality and improved lighting level is additional.  It would be seen that the use of electronic ballast alone brings-in a saving of about 10 watt.  This means that in the event only electronic ballast is replaced in place of conventional choke and the tube remains the same, the annual saving of energy will be 10 x 5x 365 = 18250 WH = 18.25 KWH or 18.25 Units equivalent to Rs. 3.5 x 18.25 = Rs. 64/-.  Additional cost involved in replacing the ballast is of the order of Rs. 120 only.  Thus, pay back period for change of choke to electronic ballast is also about two years only.  Thus, in this option of change of electronic ballast alone, a smaller investment is involved bringing in smaller savings.  But savings are savings after all.

 All the people must therefore use efficient tube lighting system.  For efficient system, initial investment is slightly additional.  If, however, the consumer wants to invest less and be contented with smaller savings, atleast the choke can be changed to electronic ballast with  a small wiring change which any electrician can do.  Not only the experience of the user will be happy, it will cause a continuos saving.