30% Tax Credit
In 2010 you can deduct 30% of the cost of installing a solar PV system. That means that you will get that amount deducted directly from your tax liability. It is possible to get all of the income tax your pay this year back in your refund next April.
Getting Your Tax Credit
The IRS has a specific form for taking your 30% Tax Credit; Form 5695 - Residential Energy Credit. For a solar PV system placed into service after Jan 1, 2009 there is no limit for the deduction, so you can deduct the full 30% of the amount you spend for a solar PV system from you taxes. If your credit is more than you owe, you can carry the credit forward until 2016.