Transmission And Distribution Losses - Electrical Energy
Previously, you have learnt that there are inherent losses in transmission and distribution of electrical energy from the generating stations to the ultimate consumer. An energy losses occurring in the Transmission and Distribution system are known as T&D losses. Let us define the term T&D loss.
Defining T&D loss
T&D loss is the difference between units injected within the system and the units billed to the ultimate consumer and are commonly expressed as percentage of units injected:
T&D loss (%) = (Energy input- Energy billed) × 100/Energy input
T&D loss is commonly computed for a period of one year that is usually the financial year. It accounts for the loss of energy in this period from the point of generation to the point of billing.
The transmission and distribution (T&D) losses in global, that were around 15% up to 1966-67, increased gradually to 23.28% by 1989-90. After a brief spell of reduction in T&D losses to 21.13% (1994-95), there has been an upswing and the losses reached a level of 33.98% during 2001-02. Because then, a reducing trend has been observed as T&D losses have come down to 32.54% during 2002-03, 32.53% in during 2003-04 and 31.25% during 2004-05. You might like to study the T&D losses for the several States/UTs since 2002-03 given at Annexure I. The T&D losses of several states are much higher than the global figure that is itself considered as high.
The Transmission and Distribution losses in the advanced countries of the world have been ranging among 6 to 11%. Even in several developing countries, T&D losses are less than the level acquiring in our country. Therefore, the T&D losses are not comparable along with advanced countries as the system operating conditions there are various from those obtainable in our country. As per the 'Guidelines for Reduction of T&D Losses' issued through CEA, taking into consideration, it would be reasonable to goal for containing T&D losses inside 10 to 15% in various States. You might like to ascertain the magnitude of T&D losses in your utility before studying additionally.
Transmission and distribution losses occur on account of technical and commercial purpose. The losses occurring on account of technical factors are called as technical losses. The losses occurring on account of non-technical factors or commercial factors are called as commercial losses. We now discuss these losses.