Electricity and water consumption for laundry washing by washing machine worldwide

Abstract

Washing laundry is one of the most widespread housework in the world. Today, washing machines do this work in many private households, using water, electricity, chemical substances, and process time. Although energy efficiency is in the focus of many regulations which have already achieved significant improvements, the question remains, how relevant these processes are in terms of the absolute impact on resources and whether there are possibilities to improve even further by looking abroad. This survey, which is based on published data, compares the energy and water consumption for automatic laundry washing in an average private household with the total energy and water consumption of private households. Only little data are available on resource consumption for laundry washing and reliable figures based on in-use measurements are hard to obtain. But although some of the data in this report are poor, this is the first work that tries to elucidate the contribution of automatic laundry washing to the total electricity and water consumption of households in selected countries worldwide. The report estimates the resource consumption of roughly 590,000,000 washing machines in 38 countries with about 2.3 billion people, which is about one third of the world population. The results of this work show that laundry washing in private households is done with quite different amounts of electricity and water in different parts of the world both in absolute and relative comparison to the overall household consumption. But due to different consumer habits in dealing with the achieved washing performance in the different global regions, the best practice in washing laundry in a most sustainable way cannot be determined yet. Further research is needed to form a basis for a most sustainable development of resource consumption in private households.

Appendices

Appendix 1: calculation of electricity consumption

The total electricity consumption, the electricity consumption for automatic laundry washing, and the share for automatic laundry washing are calculated by the following equations. As all results refer to the resource consumption per household per year, the ownership rate of washing machines by country is only a component of the equations describing weighted averages.

Total electricity consumption per household:

$$ {C_{\rm{e}}} = \frac{{{E_{\rm{t}}}}}{{{n_{\rm{h}}}}} $$

(1)

C _e :

total electricity consumption per household,

E _t :

total electricity consumption of residential sector per country,

n _h :

number of households.

Electricity consumption for laundry washing by washing machine per household:

$$ {c_{\rm{e}}} = {n_{\rm{wc}}} \times {c_{{{\rm{e}} \mathord{\left/{\vphantom {{\rm{e}} {\rm{wc}}}} \right.} {\rm{wc}}}}} $$

(2)

c _e :

electricity consumption for laundry washing by washing machine per household,

n _wc :

yearly number of wash cycles per household,

c _e/wc :

electricity consumption per wash cycle.

The share of electricity consumption for laundry washing in relation to the total electricity consumption per household:

$$ {z_{\rm{e}}} = \frac{{{c_{\rm{e}}}}}{{{C_{\rm{e}}}}} $$

(3)

z _e :

share of electricity consumption for laundry washing by washing machine,

c _e :

electricity consumption for laundry washing by washing machine per household/country,

C _e :

total electricity consumption per household/country.

Aggregated figures for West Europe, East Europe, and North America are calculated as weighted averages:

Example: electricity consumption for laundry washing by washing machine in West Europe:

$$ {\overline c_{\rm{eWE}}} = \frac{{\sum\limits_{i = 1}^{20} {{n_{\rm{wci}}} \times {c_{{{\rm{e}} \mathord{\left/{\vphantom {{\rm{e}} {\rm{wci}}}} \right.} {\rm{wci}}}}} \times r \times {n_i}} }}{{{N_{\rm{WE}}}}} $$

(4)

${\overline c_{\rm{eWE}}}$ :

average electricity consumption for laundry washing by washing machine per household in West European countries,

n _wci :

number of wash cycles per household/country,

c _e/wci :

electricity consumption per wash cycle per household/country,

r :

owner ship rate of washing machines,

n _i :

number of households per country,

N _WE :

number of households in West Europe.

Appendix 2: calculation of water consumption

The total water consumption, the water consumption for laundry washing, and the share for laundry washing have been calculated by the following equations. All figures refer to the resource consumption per household per year; therefore, the ownership rate is only a component of the equations describing weighted averages.

Total water consumption per household:

$$ {C_{\rm{w}}} = \frac{{{W_{\rm{t}}}}}{{{n_{\rm{h}}}}} $$

(5)

C _w :

total water consumption per household,

W _t :

total water consumption of residential sector per country,

n _h :

number of households.

Water consumption for laundry washing by washing machine per household:

$$ {c_{\rm{w}}} = {n_{\rm{w}}} \times {c_{{{\rm{w}} \mathord{\left/{\vphantom {{\rm{w}} {\rm{wc}}}} \right.} {\rm{wc}}}}} $$

(6)

c _w :

water consumption for laundry washing by washing machine,

n _w :

yearly number of wash cycles per household,

c _w/wc :

water consumption per wash cycle.

Water consumption for laundry washing by washing machine in relation to the total water consumption per household:

$$ {z_{\rm{w}}} = \frac{{{c_{\rm{w}}}}}{{{C_{\rm{w}}}}} $$

(7)

z _w :

share of water consumption for laundry washing by washing machine,

c _w :

water consumption for laundry washing by washing machine per household/country,

C _w :

total water consumption per household/country.

Aggregated figures for West Europe, East Europe, and North America are calculated as weighted averages:

Example: water consumption for laundry washing by washing machine in West Europe:

$$ {\overline c_{\rm{wWE}}} = \frac{{\sum\limits_{i = 1}^{20} {{n_{\rm{wci}}} \times {c_{{{\rm{w}} \mathord{\left/{\vphantom {{\rm{w}} {\rm{wci}}}} \right.} {\rm{wci}}}}} \times r \times {n_i}} }}{{{N_{\rm{WE}}}}} $$

(8)

${\overline c_{\rm{wWE}}}$ :

average water consumption for laundry washing by washing machine per household in West European countries,

n _wci :

number of wash cycles per household/country,

c _w/wci :

water consumption per wash cycle per household/country,

r :

owner ship rate of washing machines

n _i :

number of households per country,

N _WE :

number of households in West Europe.