Light Sources - Future Trends

The business of Energy Efficiency has become one of the most important issues ofthe century to curb the greenhouse gases to tackle the global climate changes. Inspite of fast track power projects etc., the power crisis in the country is worsening by the day

The lighting load in the country is approximately 17% of the total connected load which is likely to be approximately 100000 MW by the year 2000 against an average lighting load of approximately 8% worldwide. If the lighting load is reduced from 17% to 10% by the use of energy efficient light sources and control systems, the country will save 7000 MW which is equivalent of approximately 12000 MW of generating capacity. The solution therefore lies in the Demand Sale Management (DSM).

Compact Fluorescent Lamps (CFLs):

Although it is difficult to visualise the world without the common incandescent GLS bulb in spite of its being grossly inefficient and short life, the ever increasing energy costs and the growing environment concerns will force the changeover to CFLs because these save upto 80% on electricity when compared to ordinary incandescent GLS bulbs for the same light output. For example a20W CFL will replace a lOOW incandescent GLS bulb resulting in 80% saving in electricity bills.

Moreover CFLs have longer life of 12000 burning hours against less than 1000 burning hours for the ordinary incandescent bulb. Because of very long life of CFL far fewer lamps are required with further savings in power, raw material and transport.

The CFL are easy to install because the lamps with the integral retrofit Electronic Ballast have the same cap as the incandescent GLS bulb.

Fluorescent Tubes:

The growth in the Fluorescent lamps will and must continue but the emphasis must shift to energy efficient Triphosphor lamps of lesser diameter. Indeed in other parts of the world the 40W Fluorescent lamps of 38mm diameter became obsolete in the early 1980's. India also must follow the International trend because the advantages ofthe slim line Triphosphor lamps over the 40W 3 8mm tubes are many.

First and foremost the Triphosphor lamps are 50% to 60% more energy efficient. Against 290 gms. of glass used for the conventional40W tube, the new generation of lamps use much less for example only 183 gms for 36W 26mm (T8) lamp and only 100 gms. for the 28W 16 mm (T5) lamp resulting in significant savings in energy and raw materials in glass production. Also the Triphosphor lamps bave lumens depreciation of less than 5% even after 18,000 burning hours. Diversity of colour temperature of these lamps permit tailor made solutions for a variety of applications.

The modern Triphosphor lamps have a life of over 20000 burning hours against only 5000 burning hours ofthe conventional40W tubes and therefore greatly reducing the quantity of replacement lamps resulting in enormous savings in raw materials, energy and transport and recurring costs to the consumer.

Electronic Control Gear (ECG):

Increasing energy and maintenance cost and serious concerns in respect of safety, is resulting in growing realisation that the ECG must replace the conventional Electro Magnetic Copper/Aluminum Ballast. Indeed in some countries the use of Electro Magnetic Ballast is no longer permitted.

In the near distant future we expect and hope that the use of ECG will be made mandatory in high rise buildings, schools, cinemas, hospitals, hotels and public places where large number of people are likely to congregate for reasons of safety and minimising the fire hazard.

The major advantages of ECG are:

• Greater fire protection because lamp operates at lower temperature and automatic shut down of defective lamp.
• Operation at very high frequency (25-40 KHZ) ensures smooth, flicker free light with no stroboscopic effect.
• High power factor> 0.92.
  

High Intensity Discharge Lamps:

The trend here will be improvement in energy efficiency, luminous efficacy, colour rendering and compactness. With times, standard HPSV lamps will be replaced by NAV Super I SON Plus with excellent luminous efficacy particularly for street lighting and flood lighting where colour is not an important factor.

In case of the Metal Halide Lamps improvements are taking. place progressively in terms of their photometric properties such as luminous efficacy, their colour rendering and their constant colour throughout their entire life, low thermal output and long life.

The Metal Halide Lamps are also becoming more and more compact, making them ideal for indoor lighting, sales areas, shop windows, hotels, restaurants, offices and outdoor lighting such as lighting of buildings and monuments.
Higher wattage Metal Halide Lamps have become a standard for sports stadiums, flood light systems, solar simulation etc. Indeed, we should see an enormous growth for Metal Halide in the next decade.

Automotive Lamps:

The car manufacturers have long wanted their headlights to be more and more compact while at the same time producing even more light. Conventional car Lamp technology was simply unable to meet these requirements. The latest type ZENARC high pressure gas discharge lamp based on xenon is likely to revolutionise the headlights in the 21 st Century.

The use of neon, inert gas which gives out a red light when energised by an electric field in miniaturised tubes in a variety of shapes, will give a new freedom of expression to designers and stylists of Automobiles. Also in 21 st Century we will witness ever increasing use of Fibre Optics in Automotive Lighting.