MANILA, Philippines – Here’s the explanation on how we got the values in the Household carbon footprint calculator interactive page.
We used whatever available data and formulas from the Climate Change Commission (CCC) to determine the carbon emissions from household appliances and devices. Check the table below:
For computing emissions from vampire energy, we added the extra kilowatt-hour (kWh) used by the appliances or devices when on standby or sleep mode to the monthly rate of the energy they consume when being used. For example:
Television sets that are 17-32 inches wide consume 8.91 kWh per month and emit 5.37 kilograms of carbon dioxide (kgs CO2). If on standby mode and plugged in, they still consume 0.002 kWh per hour. Assuming that the TV was plugged in for 16 hours (the average per day according to studies) after you’ve stopped watching, the TV set would have still consumed 0.032 kWh per day.
0.032 kWh x 30 days = 0.96 kWh per month
We then calculated the additional carbon emissions from the vampire energy the TV set consumed using this formula: __ kWh x national average of CO2 per kWh
This is how the computation will go: 0.96 kWh x 0.6032 national average of CO2 per kWh = 0.579 kgs CO2.
Add that to the 5.37 kgs CO2 emissions from the regular electricity consumed, and you get a total of 5.949 kgs CO2.
A desktop computer, on the other hand, consumes 14.40 kWh per month, and emits 8.69 kgs CO2. When on sleep or standby mode, it consumes an additional kWh of 0.017 per hour. On average, a desktop computer is kept on sleep mode for 16 hours a day.
Applying the same formula, we can compute the additional carbon emissions from a desktop computer on sleep or standby mode:
- 0.017 kWh x 16 hours = 0.272 kWh
- 0.272 kWh x 30 days = 8.16 kWh
8.16 kWh x 0.6032 national average of CO2 per kWh = 4.92 kgs CO2
4.92 kg CO2+ 8.69 kgs CO2 monthly = 13.61 kgs CO2
For emissions from using transportation, we used the formula: daily emissions = distance / emissions factor.
We computed for the distance based on the time of travel you indicated and the average vehicle speeds based on government data:
Distance = time x average vehicle speed
The average speed of a car in Manila, according to 2006 data from the Metro Manila Development Authority, is 29.9 kilometers/hour. The average speed values for buses and jeepneys are 17.57 kph and 14.18 kph, respectively, according to data from the Japan International Cooperation Agency and the Philippines National Economic Development Authority.
Below are the carbon emission factors of vehicles from a 2013 Philippine Engineering Journal:
Finally, this is we how computed the carbon emissions from waste: we multiplied your answers by 4 to get the monthly total of your disposed waste and applied the formula below from the CCC:
Emissions per Type of Waste (kg CO2e) = Weight (kg) x Degradable organic emission (DOC) x fraction of degradable organic emission (DOCf) x Methane Correction Factor (MCF) x Fraction of Methane in Landfill Gas (F) (4) x Conversion Factor x Methane Global Warming Potential (GWP)