Electricity Usage and GHG Emissions

Objective

To calculate the GHG emissions pertaining to one’s own household energy usage. 

Outcome

Students will gain knowledge on their house’s total GHG emissions and realize what contributes maximum to the emissions based on the electrical audit. 

Requirements

Power meter, Electricity bills.

Prerequisites

• Students should have conducted the ‘Energy Audit of Own Shelter’ Activity before this activity. 
• Fundamental knowledge on use of power meter. 

Procedure

Step 1: Taking the ‘Energy Audit’ activity further, make a list of every electrical appliance used in one’s house along with its wattage details and electricity consumption. In case, it is not mentioned on the appliance and is not available on the company website as well, students can take the reading using power meter.

Step 2: Use the emission factor details and the formula given below to calculate GHG emissions of their consumption.

Step 3: Identify appliances responsible for maximum consumption and discuss strategies to reduce the consumption.

Given Data

Electricity cost: Rs. 4.2/kWh

Electricity GHG Emissions: 1.33 kg CO2e/kWh (cBalance Emissions Factor Database)

GHG emission in tCO2e = Electricity consumption (MWh)  X  GHG emission factor (kgCO2e/year)

Sample Calculation

Calculate the cost to run the appliance

Annual/Monthly cost = Energy consumed annually/Monthly x rate of utility per kWh

Using the above formula, let us find the annual cost to operate an AC.

• Run time per day: Let us assume that it is summer and you run the AC for 7 hours a day for lets say 20 days a month.
• Wattage: You will find the wattage on the label or the user manual. Let us assume it as 1500 W.
• Energy consumed daily: (1,500 x 7) ÷ 1,000 = 10.5 kWh
• Energy consumed annually: Let us assume you run the AC for 200 days in a year.

10.5 kWh x 200 = 2,100 kWh annually

GHG Emissions for 1 AC of 1 tonne = 2.1 MWh x 1.33 = 2.793 = 2.8 tonne CO2e per year

Table

Sr. No.	Appliances	Wattage (W)	Usage (No.of hours/day)	Usage (No.of hours/week)	Usage (No.of weeks/year)	Usage (No.of hours/year)	Energy Usage (kWh/year)	Qty./home	GHG Emissions (t CO2e/year)
1	AC 1 tonne	1500	7	50	200	1000	2100	1	2.8

References

cBalance Emission Factor Database: EF ready reckoner_india_Mar2012_CC_a3.pdf