Energy Efficiency Made Simple Vol IV 2015

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Illumination We have progressed from sunlight and fire to candles to gas, arc, incandescent and fluorescent lamps and now to LED lighting systems. LED lighting saves power. It is expensive to install initially but costs have come down and, as time goes by, they will come down further. The life expectancy for these lamps is long and power savings large. Conclusion Looking to the future, generation of power is an area where the envi- ronment is negatively affected if we continue with the old coal fired boiler power stations. Yes, there is pollution control on these systems, but it does not solve the problem. Efficiency of motors and transformers is moving forward but it can- not be looked at in isolation. The entire systemmust be considered. It serves no purpose to use a premium efficiency motor in an application where the motor runs on no – or very light – loads for 50 or 60% of the time; an alternate solution must be found. In distribution transformers that are loaded for short periods, iron losses become very important. Evaluate loads using a systems approach. A piece of equipment in isolation is not effective and the application and system must be considered. New materials are being developed but the challenge is how to best use these materials in the machines.

With power electronics, high voltage dc systems are available which greatly decrease losses over long transmission lines. The ac generated power is increased to very high voltages, rectified and transmitted via a dc line and converted back to ac using inverters where it can be transformed to any required voltage. With very high dc voltages corona discharge becomes a problem and the losses can offset the advantag- es. Steps can be taken to reduce the corona losses.

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ENERGY EFFICIENCY MADE SIMPLE 2015