Connection Between Energy and Water
Most Pennsylvanians know that saving water and energy is important. But do you know how closely our water and energy use are connected?
It Takes Energy to Supply Water
Not only does it take energy to heat the water in your home, it also takes energy to get water to your tap. In 2005, the nation's municipal water infrastructure consumed about 56 billion kilowatt hours of electricity—that's enough energy to power every home in Pennsylvania for an entire year. In fact, as much as 80 percent of a water utility's processing and distribution costs are for electricity.
Water utilities that depend on ground water as their primary source of supply require about 30 percent more electricity than those that get most of their supply from surface water. Pennsylvania uses 210 million gallons of ground water every day.
It Takes Water to Generate Energy
It also takes a lot of water to create energy. Vast amounts of water are used to cool power plants that generate electricity. In fact, nearly 70 percent of Pennsylvania's water withdrawals are used for generating electricity. It takes between 3,000 and 6,000 gallons of water just to power a single 60-watt light bulb for 12 hours per day over the course of a year.
The amount of water consumed by power plants creating electricity is increasing. In a typical thermoelectric power plant, cooling water is used to remove heat. The cooling water is sometimes discharged to a body of water, but this practice is being replaced with evaporating water through a cooling tower and transferring waste heat into the air instead of surface water. Evaporated water is water consumed, and it is no longer available for use in the same area. Cooling towers are becoming more preferable because they avoid the environmental impact of releasing heated water back into the stream.
It Takes Energy to Heat Water
Heating household water for bathing, shaving, cooking, and cleaning also requires a substantial amount of energy. Households with electric water heaters, for example, spend one-quarter of their total electric bill—or nearly $300 annually—just to heat water. In fact, the average Pennsylvanian homeowner pays more for energy to heat water than for all the water used in the home. Letting your faucet run for just five minutes uses about as much energy as powering a 60-watt light bulb for 14 hours.
Heating water in industrial facilities uses even more energy. Many factories heat large quantities of water as part of their manufacturing processes.
Learn More:
- The Pacific Institute published Energy Down the Drain in 2004.
- The U.S. Enivronmental Protection Agency’s WaterSense program published the fact sheet Saving Water Saves Energy: Make the Drops-to-Watts Connection in 2009.
- The World Resources Institute (WRI) published Water and Watts: WRI Issue Brief in 2009.
- The Energy-Water Nexus highlights the need for a sustainable supply of both energy and water. This site discusses how these two critical resources are explicitly linked.