Electricity Usage and GHG Emissions
Subject
Climatology
,Academic Year
2'nd Year
,Complexity Level
Intermediate
,Content tags
Climate Justice
,Energy Consumption in Buildings
,GHG Emissions
,Activity Type
Numerical Exercise
,Activity duration
1-2 hours
,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