Shower study exposes eco-myth
It’s an eco-myth that taking a shower uses only half as much water as having a bath, research we’ve carried out for Unilever reveals. In the UK, the average shower uses 62 litres of hot water compared to 80 for a bath, while a power shower gushes 136 litres.
In 2011 Unilever committed to reducing its resource use and carbon emissions.
“Supporting this drive, the company plans to design new products and influence the way people use them,” comments our project director for market research Kate Spicer.
Unilever estimates that 95% of the greenhouse gas emissions associated with its shampoos and soaps come from people using hot water, especially for showers. A clear picture of bathroom habits and their implications for energy use is a key starting point for product development.
Unilever’s in-house research and development department designed a small sensor enabling the temperature, flow rate and duration of showers to be logged. We visited 100 UK families and fitted sensors that recorded more than 2600 showers over the course of 10 days. We interviewed each family member.
Throughout the study, participants also kept diaries to track who showered when. “Our research methodology produced far more accurate results than previous studies, which have used data from questionnaires filled out by householders,” Kate says. “When self-reporting, people tend to underestimate the time spent or forget to log the activity altogether, so the information’s unreliable.”
Before our study, it was commonly believed that showering took no more than five minutes. But the average Brit in fact spends eight minutes luxuriating under the water. The cost of heating water meant that the families surveyed were spending an average of £416 a year on showering, with the most extravagant power shower costing £918 a year to run. Using our findings, Unilever has already developed a large-scale media campaign to encourage more sustainable use of energy and water through shorter showers. New, more economical washing products are in the pipeline.