The standardised LV distribution cables form network through link boxes in cities and large towns. This distribution network carries electricity from the point where transmission leaves off (at 66/33 kV level). The standard distribution covers 66/33/22/11 kVs and 0.4/0.230 kV besides them. The permissible range of frequency band is 49.95 to 50.05 Hz with the union Government regulating grid frequency and States would pay more when they draw power at low frequencies. Radial, Loop or Network are the three types of distribution system designs and a combination is also possible.
The cost of supply is the cost by the utility for one unit supply of electricity at consumer’s meeting point. In India, the industrial and commercial consumers are charged higher tariff to subsidize agricultural and domestic sectors. Worldwide, there are two systems of Cost of Supply (CoS) – Embedded CoS (ECpS) and Increment/Marginal CoS (MCoS) – the former uses accounting costs on the books of accounts of the utility whereas, the latter estimates resource costs of the utility in providing each additional unit to its consumer base. Understandably, a large volume of reliable data is essential in either cases which is not available in India. Therefore, the majority of DISCOMS opt for Simplified/Average Cost of Supply (ACoS) approach to estimate voltage wise cost. In this case, major cost elements applicable to all categories of consumers connected to the same voltage level are considered.