DCEO will accept applications until October 10th, 2014. Applications will be assigned a number as they are received, and we will have a pre-selected list of random numbers that we will use as the order we will consider applications. Any applications received after the deadline will only be consider if program funding is still available or becomes available later in the program year.
The guidelines and application are available at http://www.illinois.gov/dceo/whyillinois/KeyIndustries/Energy/Pages/01-RERP.aspx
One clarification - all solar PV and wind energy systems, except those that are self-installed, must be installed by a certified distributed generation installer.
Good luck!