Significant state and federal tax incentives are still available for the installation of consumer owned renewable energy projects including geothermal heat pumps. Because these incentives are set to soon expire please do your due diligence by fully researching the credits before undertaking a project that you believe may qualify. It may be beneficial to talk with a tax professional or CPA.
A summary of the North Carolina personal tax credits can be found at the Database of State Incentives for Renewables & Efficiency. The geothermal HVAC tax credit is included in the state's renewable energy tax credit and is equal to 35% of installed cost up to $8,400. The North Carolina Department of Revenue has issued a detailed set of guidelines for determining tax credit eligibility. The state allows you to carry the credit forward to future years.
To obtain a federal tax credit for qualifying purchases you will need to file IRS Form 5695.
The federal tax credit for the following products is 30% of cost with no upper limit:
Geothermal Heat Pumps (also qualifies for a $300 rebate from Tideland EMC)
Solar Water Heater
Small Wind Energy Systems
You can carry forward the federal tax credit as long as the credit is still in effect. In this case, the credit for these products is in effect through 2016. The energy efficiency tax credit is technically "non-refundable" so you can't get back more in credits than you paid the government in taxes throughout the year. If you are unable to claim the entire 30% of your purchase for the above named products, you can carry forward the unclaimed portion to future years through 2016.
For more information regarding federal tax credits visit Energy Star.