Isn’t that title a bit mixed up? Not once you understand the relationship between water and energy. Simply put, it takes energy to distribute water all over town as well as treating wastewater. Likewise, a considerable amount of water is required to produce energy. Approximately 4 percent of the nation’s energy is used in the distribution and treatment of water. It’s no surprise that locally, SAWS is one of CPS Energy’s largest customers. So when you have a water leak, not only is water being wasted, it takes a little bit of energy to maintain water main pressure to feed the leak. Leaks are one thing. Letting water run too long is a more serious matter and does lead to measurable energy loss. According to the EPA’s WaterSense webpage, letting your faucet run for 5 minutes uses as much energy as leaving a 60-watt light bulb on for 14 hours.
Then there’s the energy required in heating water. If you are not already using solar energy to heat water, the energy required to heat water for bathing, washing dishes, and other uses is considerable. We know you are already saving some of this energy by using only cold water to wash clothes, right? If you are using electric energy to heat water, the national average indicates ¼ of your total electric use goes to heat that water!
What about the other side of the coin? How much water is used to produce electricity? Again, not counting renewable energy from solar, landfill gas, and wind, we get most of our electricity from coal-fired and nuclear power plants with a little bit now and then from natural gas-fired power plants. These are just ways to heat water to produce steam energy to drive turbines. As you might imagine, a lot of water is required by power plants to produce electricity. That’s why power plants are located next to reliable sources of water such as lakes. According to research by the National Renewable Energy Laboratory (NREL), for the Department of Energy, these types of energy generating plants (called “thermally driven, water-cooled energy conversion cycle” or “thermoelectric” plants) required 0.47 gallons of water for every kilowatt-hour of energy measured at the customer’s meter. This is primarily from water lost to steam evaporation during the energy production process, not water running through the plant and returning to the lake or other water source. In San Antonio, CPS Energy claims that currently, 11 percent of our energy comes from wind, landfill gas, and solar sources. That means 89 percent of our energy is from thermoelectric plants. So, for our particular mix, it takes 0.42 gallons of water used for every kilowatt-hour of energy measured at our home electric meters (assuming no water is used in the production of electricity from our wind, landfill gas, and solar sources).
So, if leaving your water run for five minutes uses as much energy as leaving a 60-watt light bulb on for 14 hours, remember too, that leaving a 60-watt light bulb on for 14 hours means another 0.35 gallons is lost to produce that energy. When you are careful about your water use, you’re saving energy. And when you save energy, you’re saving water. Makes you feel good to do both, doesn’t it?