By Shafiq Minhas

SINCE THE energy crisis in Pakistan has badly affected almost the whole fabrics of the national economy, the official policy makers have joined their heads to find out a lasting solution to get the country out of this persistent crisis where they could explore the potential of alternative energy or at least work out some austerity initiatives in order to effectively save energy.

As there are several sectors where power energy is being consumed without realizing that this energy can be saved if the authorities give a serious thought to it, the streetlights across the country have emerged as a visible sector which consumes as many as 600 megawatts. This could reach the level of over 1400 megawatts if line losses are included in it, which is nothing but a major factor of energy waste.

Electricity expenses for the public lighting have become an important item on overall electricity budget in public administration sector. Some account the current tariffs are Rs. 15.04 per unit with the 11 average lighting hours a day or 3,830 hours annually. In the wake of the yawning power shortfall gap in the country especially in the summer, the official power managers opt for austerity measures and work out load management especially in shape of fixing business hours at night at markets. As the past experience shows that this could hardly save few hundred megawatts which looks a futile exercise against the rising demand for power. But as far as streetlights are concerned, power can be saved significantly if efficient lamps are installed as it consumes far less energy but gives the same light. Similarly, the installation of efficient ballast could save electricity for having low power factor.

Electricity wasted on the line depends on the square of the current and from the power factor; thus reducing the current 2 times means cutting line losses by 4 times. Similarly, reducing power factor means less current going back and forth. Mantaining the full power in the full night is even a wastage of power. If the electronic dimmable ballast is installed, it would remarkably reduce power usage.

SIRA Private Limited – a subsidiary of Sira Italy is offering most efficient street light solutions. Sira SOX light 66watt with Sira high performance electronic ballast has emerged as the best viable option to cope with the situation. In addition, new generation master SON T light with SIRA high performance electronic ballast (re-lamping) has proved to be an effective replacement of old lamps.

The currently installed 250 Watt lights, consumes a real power that is due to the lamp itself (250 Watt) plus the power wasted inside the magnetic ballast (other 75 Watt) and finally the power wasted on the electrical lines (75 Watt more). The final power used by each 250 watt lamp currently installed in Pakistan,  becomes more than 400 Watt .

Two different options can be adopted to greatly reduce the power used for street lights.

For new installation, the adoption of Low Pressure Sodium (LPS)  lights allow a saving till 90 %; LPS lights have an efficiency of 170 lumens/watt and are the most efficient existing light technology (a branded LED street light has about 105 lumens/watt) and is not subject to degradation due to the high temperatures.

For existing lights, the replacement of the lamp and the ballast with more efficient lights and ballast, is a cheap solution that allow a saving of more than 60% of power (and improving the quality of light), respect the currently used lights.

On an experimental basis, Sira has installed along Main Road of W Block 5, DHA, Lahore, SIRA-SOX-6 lights complete of fixture (N° 5 lights), Sira electronic ballast and the low pressure sodium lamp of 66 watt, on the existing poles, replacing the old street lights. The company has also re-lamped old lights with SIRA-kit SON T 150 Watt on other 5 existing lights.

The two-month trial results (from 23-9-2012 to 23-12-2012) reveal that with using Sira SOX-6 (66watts) lamp only 0.3 unit per night was consumed showing 90 per cent saving while the light increased up to 52 per cent.

Similarly, the Sira KIT-T 150 lamp only 55 units were consumed in two months (0.9 units per night) showing 72 per cent saving while the light increased up to 64 per cent.

In addition, the Sira Master KIT 150 has 26,000-hour life with the dimmable feature and is good in frequent start conditions with excellent lumen maintenance. Similarly, the SIRA SOX 6 Low Pressure Sodium with the top efficiency of 170 lm/W have  no problem with outside temperature, good in fog and no glare. Its life span is upto 18,000 hours with very high lumen maintenance till the life end (90%).

The SIRA high performance electronic ballast voltage range is 100 to 250 volts having high voltage spikes protection for Electrostatic Discharge that are the cause of early failures during storms. It efficiently works in extreme temperature from -10 to 70 °C.

SOX light gives more light output for the energy than any other lighting source. In a time when many people are demanding more energy efficiency for environmental reasons, an installation of SOX lighting will consume significantly less energy than the more modern SON , metal halide and LED lamps which run on a higher wattage and have less light output.

The main advantage is that it has a relatively low operating temperature – it means that it can be used with lightweight plastic components and is good for tunnel lighting. The SOX lamp can be operated on low-cost electrical control gear and does not require a cooling-down time before they switch back on.

Light experts strongly believe that SOX lights are the best all-round solution for general road lighting.

This lighting is good for illuminating areas like crime hotspots, tunnels, roads and parks, while shopping centres, major road may best be served by white-light streetlights such as SON (high-pressure sodium) or ceramic  metal halide lamps.

Technology TimesArticlesenergy,lights,major,saver,SOXBy Shafiq MinhasSINCE THE energy crisis in Pakistan has badly affected almost the whole fabrics of the national economy, the official policy makers have joined their heads to find out a lasting solution to get the country out of this persistent crisis where they could explore the potential of...Pakistan's Only Newspaper on Science and Technology