Yes, you can actually save money by installing a Drain-water Heat-recovery system in your home. It works to warm up water for your shower by using heat from waste water as it goes down your drain. These systems are available for other appliances as well, such as dishwashers.

According to experts, if your house uses enough water to take four seven-minute showers each day while using a standard shower head, you will save 183 cubic meters of natural gas per year. If you have electric water heating, you can save 1,479 kilowatt-hours per year. These systems cost between $500 and $700, and cost an additional $100 for installation. So, depending on your type of energy and the rates you pay, the system could actually pay for itself in as little as 2 1/2 years.

Always shop around for rebates if you decide to install one, as many power companies do offer them.