If you are asking about 2009, see this 2009 CEE link. It is too late, however, to include this on a 2009 tax return. For 2021:
You can't claim Energy Star appliances or water-saving improvements like low-flow toilets, low-flow shower heads, or xeriscaping on your federal return. However, many state and local governments and utility companies offer incentives or rebates for energy- or water-saving home improvements. An online search will reveal what your state has to offer (for example, you might search for Arizona toilet rebate or California water-saving incentives).
Under the Residential Energy Efficient Property Credit, you can get a federal tax credit for installing alternative energy equipment, such as solar electric property, solar water heaters, geothermal heat pumps, small wind turbines, and fuel cell property.
If you made energy-efficient improvements to your home like energy-saving roofs, windows, skylights, and doors, you'll be able to claim the Nonbusiness Energy Property Credit for 10% of amounts paid for qualified energy efficiency improvements, up to a lifetime cap of $500 or fixed dollar amounts ranging from $50 to $300 for energy-efficient property, including furnaces, boilers, biomass stoves, heat pumps, water heaters, central air conditioners, and circulating fans.