The U.S. Government offers two tax credits for improvements in energy efficiency. One focuses on improvements to your home's energy efficiency. The other program rewards renewable energy investment in your home. The credit is non-refundable, meaning that you can't receive more money back in tax credits for 2011 than you paid in federal income taxes.

The Residential Energy Efficiency Tax Credit provides a tax credit of 10 percent, up to $500, of energy efficiency upgrades such as heat pumps, furnaces, air conditioners, insulation, water heaters, windows, doors and roofs. Starting in 2011, $500 is the lifetime limit for this tax credit. This means that if you received any Federal Energy Efficiency Tax Credits between 2006 and 2010, those count towards this $500 lifetime limit. Thus, if you've received $500 or more in these credits previously, you would be ineligible for further tax credits under this program. The credit also only applies to your primary residence, and it must be an existing home. Act fast, because the tax credit expires at the end of 2011.

The Residential Renewable Energy Tax Credit is a 30 percent credit of the total cost for solar panels, wind energy, solar water heaters and geothermal heat pumps. There is no cap to the total dollar amount of the credit towards these items. In addition, fuel cell installations also qualify for a 30 percent tax credit, but the credit is capped at $500 for each 0.5 kilowatt of capacity. Each of these rebate programs expires at the end of 2016, giving you time to plan a renewable energy project to cut your energy bills.