BREAKING DOWN SYSTEM’S LOSS COMPONENTS TUTORIALS

BREAKING DOWN SYSTEM’S LOSS COMPONENTS TUTORIALS
How Electric Utilities Compute for the overall system’s loss value?

We have discussed in our previous topics the main components in computing for the system’s loss of a typical electric utility namely the Purchased, Sold and Company use kilowatt-hours. The main principle behind the determination of system’s loss revolves mainly in the amount of unaccounted kilowatt-hour loss in comparison to the total kilowatt-hour purchased.

Electric Utilities system’s loss differs from one another due to the reason that each utility possesses a unique network of electrical system. Some may have a dense loading profile while others may have relatively scattered loads. The usual reason why some utilities have higher line loss can be explained by the presence of over-extended lines just in order to serve customers in the remote area.

Most electric utilities/cooperatives are supplied with electricity from more than one source to ensure reliability of supply. The mix of these powers can be quite a number depending on the location of the source. A single utility can have a source coming from various locations like but not limited to hydroelectric, geothermal, coal-fired, nuclear, etc.

In dissecting the purchased portion of the computation of the system’s loss, a utility must have a reliable source of metering for all the supply utilized by the company. On the other hand, customers can also be categorized according to the nature of their loads like residential, commercials, industrial and flat rates. Scheduling customers would be helpful in identifying which customers contribute more to the losses of the utility.

Below is an example of an electric utility’s system’s loss computation for a month reading. This is how a utility usually computes for their monthly system’s loss.

KWH PURCHASED            
                Metering Point A:                         26,152,659
                Metering Point B:                           2,518,154
                Metering Point C:                              542,995
                Generation A:                                      12,548
                Generation B:                                        6,584
                TOTAL PURCHASED             29,232,940

KWH SOLD
                Residential:                                      8,548,785
                Commercial:                                    5,441,789
                Primary Metered:                             9,595,148
                Flat Rate:                                         3,589,844
                TOTAL SOLD                            27,175,566

COMPANY USE
                Building and Office:                             123,546
                Remote Office A:                                    1,542
                Remote Office B:                                    1,023
                Station Loads:                                         5,149
                Other Buildings and Offices:                        842
                Canteen:                                                     552
                TOTAL COMPANY USE                 132,102

UNACCOUNTED LOSS = PURCHASED – (SOLD + COMPANY USE)

UNACCOUNTED LOSS = 29,232,940 – (27,175,566 + 132,102)

%UNACCOUNTED LOSS = UNACCOUNTED LOSS / PURCHASED

%UNACCOUNTED LOSS = 1,925,272 / 29,232,940

% SYSTEM’S LOSS = 6.58%

Obtaining the percent system’s loss of the electric utility can be a good indication whether the company is efficient in delivering power. The only problem with this procedure is the determination of kwhr sold since it would be very hard to read the entire customer all at once in a single day. A timing difference is present that could somehow make the computation far  from the actual value.