South Africans tend not to think twice about the cost of a shower or bath, since both electricity and water used to be very inexpensive.
Is this still true in 2021? Our previous study in 2017 was a real eye-opener, with the cost of a 10-minute shower using a 15 litre/min showerhead coming to just under R13/shower.
We have now updated the study using the latest approved municipal tariffs for the tariff year July 2021 to June 2022. Unfortunately things have only gotten worse…
Here is the summary data for 2021.
For an average middle-class household in South Africa (LSM7-10), a 10-min shower costs almost R20 if you have a ‘standard’ 15 litre/min showerhead! This is about R1.95/min. By changing to a low-flow showerhead and reducing shower time to 6 minutes, you can dramatically reduce this to just over R6 per shower (or R1.04/min).
In either case, it appears that the days of ‘cheap’ showers are numbered, and we can all do with being more aware of just how much water & electricity we use in the shower or bath.
Conventional wisdom has it that showering uses less water than running a bath. However, a typical bath uses 90 litres of water, so if you shower for longer than 6 minutes with a ‘standard’ showerhead, you will actually use more water than if you had a bath… With an average shower time internationally of 8 minutes, a shallow bath might actually be better for your pocket and the environment!
Of course, even better than a shallow bath is to switch to a low flow showerhead and have shorter showers… City of Cape Town recommends showering for less than 2 minutes, and switching to low-flow showerheads (less than 10 litres/min) is compulsory according to City of Cape Town bylaws.
The graphs below show more detailed information on water & energy use and cost per shower for normal & low-flow showerheads, and compared to a ‘standard’ 90 litre bath.
Average bath uses about 90 litres of water. Waterwise. Last accessed: 12/09/2017.
“Normal” or standard showerheads use 15 litres of water per minute or more, and low flow showerheads use about 8 litres water per minute. Eskom fact sheet on showerheads. Last accessed: 12/09/2017.
Average effective residential water & electricity tariffs were calculated from the published 2021/22 tariffs of the following four metropolitan municipalities: City of Johannesburg, City of Tshwane, City of Cape Town and Ethekwini, using the average residential water and electricity consumption values for LSM7-10 obtained from the above references.
For ‘lower income’ households, the average water & electricity tariffs are somewhat lower across the four municipalities (due to lower average consumption), at R2.37/kWh for electricity and R37.88/kilolitre for water & sanitation. This yields a cost per bath of R9.59, a cost per 10-minute ‘normal showerhead’ shower of R15.98/shower, and a cost per 6-minute low-flow showerhead shower of R5.11/shower.
Energy cost of hot water based on heating water from 15 to 60°C, which requires approximately 5.22 kWh per 100 litre.