The Energy Accounting Procedure

Here, you have learnt which energy accounting in the electricity sector includes evolving procedures and checks to account for energy from generating stations down to the consumer level.  The several steps in the energy accounting procedure are:

• Measurement of the available energy (the energy input);
• Measurement of the energy consumed; and
• Estimating the energy lost, the revenue realized and the commercial losses.

The deficit in the cost of energy available at the meter and the billing collections provide an estimate of the AT&C losses. Figure and Table show how a classical town area could be divided for the reasons of energy accounting.

Figure: The Town Level Grid to Consumer Supply and the Administrative Setup from the JE to CE Level

               Table: Organisational Structure and Areas of Responsibility for Energy Accounting

We should discuss in a while how the technical and commercial losses could be segregated.

For distribution utilities, the focus of energy accounting should be on grid substations whereas sub-transmission systems (66/33/11kV) take off commonly as a radial system to supply power to consumers at variant voltage levels. Remember in which feeders emanate from every substation towards the customers. The feeders at 11kV are taken to the load centre and terminated within a distribution transformer (DTR). The customers are connected at 220 V from the secondary of the distribution transformer.

In sequence to implement the energy accounting process successfully, utilities should adopt a bottom-up rather than a top-down approach to energy accounting. The reason is extremely easy. The first view of the loss could be acquired through monitoring the energy input to a particular feeder and the amount of energy bill collected. Therefore feeder becomes the focal point and must, thus, be the first point of check and measure. Each Junior Engineer should be entrusted along with the responsibility of covering one or more 11 kV feeder(s) that could be feeding a number of consumers. S/he should be responsible to account for the energy received through the feeder and billing of consumers connected to it.

The subsequent steps could be taken at the feeder level for energy accounting:

a.)     measure the energy received at the feeder;

b.)    list the customers billed;

c.)     record the revenue from bills;

d.)     compute the difference in billing and collections from customers; and

e.)   acquire the difference in input energy cost at the feeder level and the total revenue realized from collections.

In the further step, energy accounting could be done for the set of feeders at the substation level and then for the group of substations at circle level and at last for the town area. The hierarchy in this distribution could be matched with the administrative hierarchy for the reasons of accounting as shown in Figure.

Responsibility could be fixed for the higher levels like SE Level, EE Level, and CE Level. The exercise would include establishment of an energy measurement system and preparation of energy balance associated to the various responsibility areas. It would also need the segregation of technical and commercial losses. Let us now look at these aspects.