I’ve just run across this site which as stated on the site is a:
comprehensive source of information on state, local, utility, and federal incentives that promote renewable energy and energy efficiency.
The site is prepared by the North Carolina Solar Center and is a great place to start for locating incentive and rebate programs in your area. Although it should not be considered the only source for this information, it is quite comprehensive.
DSIRE - Database of State Incentives for Renewables and Efficiency
