You may not need water that hot unless you have a dishwasher. When buying new appliances, compare the Energy Guide labels of competing models of the same capacity to determine their annual energy cost ranges. The energy thrifty machines will be more economical over time. Use cold water rather than hot to operate your food disposer. Besides saving the energy needed to heat the water, this aids the disposal in getting rid of grease.
Grease solidifies in cold water and can be ground up and washed away.
Install an aerator in your kitchen sink faucet. This lowers flow only slightly, but reduces the amount of water that needs to be headed. Keep range-top burners and reflectors clean. They will reflect the heat better and save you energy. Match the size of the pan to the heating element.