Utilisation of Electrical Energy Assignment Example | Topics and Well Written Essays - 2500 words

Utilisation of Electrical Energy - Assignment Example The average consumption of electric energy around the world is approximately 19 % of the total electric energy produced. This calls for the specialized improvement in the lighting efficiency to save energy which translates to conservation of the environment. Different environment requires different lighting luminaries. The choice of a specific lighting luminary in a given environment depends on several factors. Some of the factors that influence the choice of lighting luminaires in given environments include the availability of natural light, the intensity of light required, the availability of energy sources – in this case electricity – among others. This paper discusses the common discharge luminary in different environments. The chosen environments include office building, an indoor – 5 –a – side – pitch, and Cul-de-sac street lighting Office Building For efficiency lighting in an office building, there must be sufficient source of light. This implies that the lighting luminaries used must have a high light intensity. Since the light is always switched on, the luminary must have the capacity to save energy. Considering this factors among others, the best luminary suited for an office building is Fluorescent Lamp. This is the best choice due to the following advantages: Fluorescent lights are cheap Fluorescent lamps generally have a very good luminous efficacy Fluorescent lamps have a very long lamp life (Ranges from 10 000 hours to 16000 hours). This implies less maintenance costs They come in large varieties of CCT and CRI Fluorescent Lamp Construction, Operation and Associated Circuitry The associated circuitry of fluorescent lamp is shown in figure 1 below. Figure 1. The associated circuitry of a fluorescent lamp. Construction and Operation In a fluorescent lamp, light is predominantly produced by fluorescent powders which are activated by ultra – violet radiation originating from mercury. This type of ligh t source is characterized by low – pressure gas discharge light source. Physically, the lamp is composed of a long tubular pipe that contains an electrode on both sides. This tubular pipe is filled with low pressure mercury vapour which is enhanced with an inert gas, in this case, argon, for starting. The emission of the light occurs in the ultraviolet region. The wavelength of the energy emitted falls in the range of 254 – 185 nanometres. The ultraviolet radiation produced is, then, converted into light by the phosphor layer which is coated on the inside of the tube. Most of the initial photon energy, 65 %, is lost by the dissipation since one ultraviolet photon produces only one visible photon. Moreover, the final spectral of the light that is distributed can be varied. This is by different combinations of phosphors. The CCT (Correlated Colour Temperature) of fluorescent light varies from 2700 Kelvin to 6500 kelvin. On the other hand, the colour rendering indices var ies from 50 to 95. Different fluorescent lamps have different luminous efficacy depending on their construction. The latest fluorescent lamp has a luminous efficacy of 100 lm/W. This excludes the ballast losses. The operation of a fluorescent lamp is shown in figure 2 below. Figure 2. The operation of a fluorescent lamp. Fluorescent lamps have an ever increasing current. This is harmful since it can destroy the lamp (National Industrial Pollution Control Council. Electric and Nuclear Sub-Council, United States. Dept. of Commerce, 1972). Thus, to correct this, it is designed in such a way that it limits the lamp current. This is seen in instances where it displays the negative voltage to counteract the ever increasing c