"...use the sun to rein in utility bills. A solar water heater system will typically cost more than a conventional system to install, according to the DOE. But it can trim your hot water expenses by 50% to 80%, so they can pay for themselves within a few years, depending on your usage. Don't forget the 30% federal tax credit on the purchase, and check to see if your state and local governments offer incentives."

Read more: http://www.foxbusiness.com/personal-finance/2010/12/13/handy-ways-save-home-rehab/