Chances are you can turn down the thermostat on your home's water heater a few degrees and still have plenty of hot water for everyone's daily shower, not to mention the dishes and laundry.
Installers and builders often think they're doing homeowners a favor by jacking up a water heater's temperature (commonly to 140 degrees F). Maybe such hardworking folks really appreciate a long, hot soak. But it's not necessary for most households to keep the appliance set to anything over 120 degrees F.
Lowering the temperature from 140 to 120 would reduce your water heating costs by 6 to 10%. Give it a try. Many people find that tweaking the dial can be addictive, and it's easy to reduce the temperature further to 115 or even lower.