Feeder Energy Accounting: Loss Is Not Automatically Theft

Electrical Engineering · CHAPTER 5 / 5

Level: introductory undergraduate · Study session: 15–20 minutes including practice.

Learning outcome: Build a time-aligned energy balance and identify uncertainty.

Before you begin: Complete earlier chapters in this discipline; revise algebra and units as needed.

1. Understand the idea

Compare imported feeder energy with energy delivered over the same dates, boundary and meter basis. The residual includes technical losses, meter and timing errors, unmetered supplies and possible non-technical losses. A large residual supports investigation, not a finding of theft. Monthly energy cannot directly reveal maximum demand.

2. Write the model

Residual = Ein − Eaccounted; residual% = 100 × residual/Ein

Define the symbols from the worked case before substituting values. Keep units consistent, record the assumptions and round only after the calculation.

3. Follow a worked example

For 100,000 kWh feeder input and 90,000 kWh accounted delivery, the residual is 10,000 kWh or 10%. Estimating technical loss and billing-period mismatch is necessary before interpreting the unexplained portion.

4. Explore the model

Figure: calculated teaching cases; straight segments connect sampled points, not experimental observations. Read exact values below.

Illustrative scenario sweep — synthetic educational data
Accounted energy (kWh)	Input (kWh)	Residual (%)
85000	100000	15
90000	100000	10
95000	100000	5

Vary accounted delivery while holding input fixed. Then list which residual components could change without theft.

5. Reproduce it yourself

Copy the input cases into Excel or a notebook and name each quantity and unit.
Recalculate each result from the stated equation or rule. For qualitative cases, explain the state or partition decision instead.
Change one input, predict the direction of change, then calculate again.
Write one sentence explaining where the model stops being valid.

6. Check your understanding

If input is 50,000 kWh and accounted energy is 47,500 kWh, what is the residual?

Reveal the answer and check your work

2500 kWh or 5%.

Compare your result, units and reasoning. If they differ, return to the equation and test the worked case first.

7. Common mistake

Do not label consumers as fraudulent from an aggregate balance.

Further study and academic note

Explore the discipline reference and further learning resources. This is an original IIMEEE introductory teaching note with synthetic examples; it is not a peer-reviewed research result or a professional design specification. Figures were constructed from the listed teaching cases. Resource links support further study and do not imply endorsement.