Incentives for renewable energy applications are available from several sources based on your location. Some areas have state and municipal incentives, some have state only, and some federal only. However, the 30 percent (with no limit) solar Investment Tax Credit (ITC) is available to everyone until December 31, 2016.
For more information on the solar ITC follow this link. http://www.seia.org/policy/finance-tax/solar-investment-tax-credit.
The DSIRE (Database of State Incentives for Renewables & Efficiency) website should be the first stop when looking for information on renewable energy incentives and policies. Funded by the Department of Energy and maintained by North Carolina State University, the site is updated regularly and is comprehensive, tabulating all local and state incentives for solar PV and solar thermal. Although it is currently being updated, it is still a valuable resource for incentives in your area.