One morning I realized that I could cut down my showering time by at least one minute if I could combine my shampooing and conditioning into one step. I went to a grocery store looking for a combination shampoo and conditioner that really works. I’m still looking, but I know they are out there.
A study commissioned by the California Department of Water Resources looked at water use in California single-family homes. The study determined that showering was the third largest user of water inside a home, after toilets, which are the biggest users, and washing machines the second biggest.
There are about 36-million people in California. Each person uses about 18 gallons of water each day for a shower. I’m not including baths, but baths generally use as much as or more water than showers. The average shower lasts about 9 minutes. Average flow rate is about 2 gallons per minute. If just 10% of us switched to a combination shampoo and conditioner, shaving at least a minute off of our shower time, it would save the state:
1/9 minutes x 18 gpm x 365 days x 3.6 million people = 2,628,000,000 gallons of water each year
Anywhere from 50%–75% of the water in a shower—depending on the preference of the person taking the shower—comes from the water heater. To heat a gallon of water from 600F to 1050F takes about 375 Btu, which is the equivalent of 0.1 kWh. At a price of $0.12 per kWh, the cost of heating a gallon of water is about one cent. If half the water used in a minute of showering is heated water, and one out of ten of us switched to a combination shampoo and conditioner, the amount of energy we could save and the cost of that energy is about:
2.63-trillion gallons x 0.5 x 0.1 kWh = 130-million kWh of power saved each year
130-million kWh x $0.12 per kWh = $15.8-million saved each year
For an individual, switching to a two-in-one shampoo and conditioner could save more than 730 gallons of water a year and save about $4 in energy costs.