Electricity Bill Analysis

Objective:

To understand how an electricity bill is calculated

Outcome:

Students will become aware of the variable electricity tariff structure designed.

Requirements:

Monthly/bi-monthly electricity bill.

Prerequisites:

A conceptual knowledge of electrical energy generation and transfer processes. 

Procedure:

Step 1: Note the connected load (kW) mentioned on the front page of the bill.

Step 2: Note the current month’s consumption (determined by subtracting the electricity meter reading of the present month from previous reading).

Step 3: Go through the variable tariff structure on the back of the bill, and determine the tariff category based on current month’s consumption.

Step 4: Calculate total tariff charges (mentioned in the tariff structure) based on the respective tariff category.

Step 5: Calculate the final billing amount by adding electricity tax and duty, mentioned on the back side of the bill.

Step 6: Tally each of the tariff charges with the detailed break-up of billing charges (provided at the back of the bill) and the monthly billing amount. All values should match.

Sample calculations (for a monthly bill):

Conversion Factor:

1 kWh = 1 unit of electricity 

Step 1: Connected Load (P) = 3.5 kW

Step 2: Monthly Consumption (E) = 164 kWh

Step 3: 

Calculation Table:

Tariff Category	Units / month	0 – 100	101 – 300	301 – 500	> 500
Fixed Charge (CF)	₹ / month	–	95	–	–
Energy Usage (EU)	Units	100	64	0	0
Energy Charge (CE)	₹ / Unit	2.60	5.62	7.20	8.95
Wheeling Charge (CWC)	₹ / Unit	1.70	1.70	1.70	1.70
Regulatory Asset Charge (CRAC)	₹ / Unit	0.20	0.33	0.39	0.49
Fuel Adjustment Charge (CFAC)	₹ / Unit	0.3774	0.6774	0.7998	0.9340
Total: CF + EU x (CE + CWC + CRAC + CFAC) (Tx)	₹	487.74	627.95	0	0

Tariff Category	Units / month	0 – 100	101 – 300	301 – 500	> 500
Fixed Charge (CF)	₹ / month	–	95	–	–
Energy Usage (EU)	Units	100	64	0	0
Energy Charge (CE)	₹ / Unit	2.60	5.62	7.20	8.95
Wheeling Charge (CWC)	₹ / Unit	1.70	1.70	1.70	1.70
Regulatory Asset Charge (CRAC)	₹ / Unit	0.20	0.33	0.39	0.49
Fuel Adjustment Charge (CFAC)	₹ / Unit	0.3774	0.6774	0.7998	0.9340
Total: CF + EU x (CE + CWC + CRAC + CFAC) (Tx)	₹	487.74	627.95	0	0

Step 4: Total Tariff Charges (T) (₹) = T_0-100 (₹) + T_101-300 (₹)

= 487.74 + 627.95

= ₹1,116

Step 5: Billing Amount (₹) = T + Government duty (16% of T) (₹) + State 

Government Tax (0.1604 ₹/unit) x E (units)

= 1,116 + 1116 x 0.16 + 0.1604 x 164

= ₹1,320 

References:

https://docs.google.com/document/d/1jfNw90P9eA2KYKF_byYNgyHObXy959_WBh9MRc5YSF8/edit#heading=h.lqorxwmjlqbw