Assumtions
The utilities taken into consederation are space heating, space cooling, lighting and appliances. As an increase in HH size tends to decrease the level of emissions (living together also means the energy, e.g. used for heating is partly shared to serve the). The living space needed by one person also impacts directly the energy needed for space heating and cooling (Druckman A., Jackson T. 2016; J. Jin et al. 2019).
Methodology
The calculator is designed to help user to understand how the carbon footprint of individual household energy emission are composed and influenced. Data for this calculation are obtained from the International Energy Agency (IEA). Based on the total residential energy consumption per segment and the total residential emissions, the segment specific emissions were derived by the country specific emission factor.
What is Included?
Energy in households is consumed at different stages. In accordance with the input-output based approach of IEA, GHG emissions/capita are segmented in the following areas:
Residential space heating: This consist of the dedicated area/room heating and central heating systems. These systems have the capacity to heat up the entire house. Examples of such are steam systems and hot water with radiators, wall or floor furnaces, district heating etc. Others like fireplaces, stand-alone electric heaters/stoves make use of oil products or other fuel types like wood or coal.
Residential space cooling: This includes the central air conditioners which could be connected to a duct system that can also serve as a central heating system. Other available cooling systems such as swamp coolers cool the air via water evaporation and heat pumps could also be used to air-cool when used in the reverse form. Most cooling systems in households run majorly with electricity.
Residential lighting: Light bulbs used for illuminating the interior and exterior of households are powered by electricity and this could be either Incandescent lamps or more efficient/durable ones like light emitting diodes (LEDs), compact fluorescent lamps and fluorescent tubes.
Residential appliances: This can be categorized into two major types; large appliances like clothes dryers, air conditioners, dishwashers, kitchen stoves, freezers, water heaters, refrigerators, washing machines, induction cookers, etc. The second category include smaller appliances like blender, food processor, toaster, coffeemaker, etc.
Others: This consists of all other HH energy consumption use in the services sector that are not space heating, space cooling, and lighting.
Calculation
Our calculation is in accordance with highly reviewed academic research, i.a. D. Pandey et al. 2011; R. Shirley et al. 2012; R. Miehe et al. 2015 and the IEA 2020 report. To obtain the total energy emissions per person in one specific country, the respective footprints of the above-mentioned categories were accumulated.
On Average, the largest part of the carbon footprint represents the space heating, cooling and space lightning (IEA, 2020). As those are expected to be strongly dependent on the living conditions of the respective person, we enabled further specification of the living space and the people in the household by the user. Taking the national averages as default, an augmentation in living space leads to a proportional rise in the energy emission, while an increase of people in the household leads to a respective decrease in the emissions per person, as an above average sum of people now share the same living space. With this approach we majorly followed the scientific attempt of the IEA, D. Pandey et al. (2011) and R. Miehe et al. (2015). In the following, variables to increase accuracy of the individual carbon emissions are elaborated.
Country: Tukker et al. (2010) shows evidence, that HHs situated in places with extreme climate conditions tend to have a higher amount of carbon emissions because of the energy needed for air conditioning and/or space heating but this effect can be further be moderated by other determinants like type of house construction and the energy type used. Therefore, the national average per capita is applied as a base value.
Household size:This total people in one HH is considered an important factor in HH emissions. The more people, the less energy is required due to the energy sharing occuring amongst the occupants (Druckman A.; Jackson T. 2016). This reason shows that as population densities increase, emission per capita decreases (D. Wu et al. 2020)
Living Space: Effect of living space on individual energy consumption/carbon footprint is directly proportional (J. Jin et al. 2019). On average in the US, an HH consumes between 143–175 kWh/m2 and this would rise as the living space increases (B. Goldstein et al. 2020).
The total residential emission is estimated by adding the different emission segments (space heating, space cooling, lightning, appliances, and others). For space related emissions (heating/ cooling/ lightning), we multiplied the influencing factor.