For existing homes (must be primary residence), tax credits are available at 30% of the cost, up to *$1500 maximum for all improvements combined, for the following upgrades made between January 1, 2009 and December 31, 2010:

 
Windows & Doors
Insulation
Roofs (Metal & Asphalt)
HVAC (Heating, Ventilation, and Air Conditioning)
Water Heaters (non-solar)
Biomass Stoves (burns renewable plant-derived fuel)

*Installation costs ARE NOT COVERED by the tax credit for Windows & Doors, Insulation, and Roofs. The tax credit available is toward the cost of materials only. Installation and product costs ARE COVERED for HVAC Systems, Water Heaters, and Biomass Stoves.
 
For existing homes and new construction (second homes and rentals qualify with the exception of Fuel Cells, which must be in the primary residence), tax credits are available at 30% of the cost, with no upper limit, for the following installations or upgrades made between January 1, 2009 and December 31, 2016:
 
Geothermal Heat Pumps
Solar Panels
Solar Water Heaters
Small Wind Energy Systems
Fuel Cells
 
Installation and product costs ARE COVERED for each of the above. Note that the tax credit for Fuel Cells is limited to $500 per .5 kW of power capacity.

 
As with any tax deduction, it is necessary to maintain records on any qualifying improvements made. Save all manufacturer's labels, certification statements (certifying the product qualifies for the tax credit), and sales receipts.

 

Additional tax credits are available to contractors for new construction and toward new manufactured homes. Specific energy saving criteria must be met to qualify.

The above information gives you a brief overview of the tax credits available for eligible home improvements, upgrades and new construction. There are many qualifying factors and specifications that apply to each product. It is important to do your homework so you understand the criteria applicable to the project you have in mind. For specific details and links to other useful and related information, visit Energy Star's Federal Tax Credits for Energy Efficiency.

Hybrid & Electric Vehicles
Tax credits continue to be available toward the purchase of hybrid cars that were placed in service starting January 1, 2006. The credit is determined comparing fuel economy, vehicle weight and technology to base year models. After qualifying manufacturers have sold 60,000 eligible vehicles, the credit will be phased out over 15 months. Credits will no longer be available for vehicles placed in service after December 31, 2010 for those manufacturer's that have not reached the end of the phase-out.

 

Starting January 1, 2009, there is also a tax credit available for purchasing plug-in electric vehicles. The credit varies from $2,500-$7,500 and is measured by the capacity of the battery system. After the first 250,000 vehicles are purchased the program phases out.
 
First-Time Home Buyers
Not only can buyers take advantage of record low interest rates, the stimulus plan has passed an $8,000 tax credit to eligible first-time buyers. Unlike the $7,500 tax credit that was passed last year, the new tax credit does not have to be repaid unless the home is sold within three years from the date of purchase. The tax credit is available to taxpayers purchasing a primary residence between January 1 and December 1, 2009 and whose adjusted gross income does not exceed $75,000, or $150,000 for married couples.