We are architecture students in a design competition and are designing a netzero house. We hope to use 12" sips but need to span 30 in one area. We are wondering if a wood sip can span that distance and be able to support solar panels.

The short answer is no. I-joists (like Boise Alljoist)could be used at the panel connections to increase strength (but even then the deflection is borderline for what the code allows). This is a good opportunity for you as a student to become familiar with the code and evaluating product capabilities. In Florida a good source for this online is http://www.floridabuilding.org/c/default.aspx Code Minimum deflection is under R301.6-7 (online residential code) and you can look up approved product engineering data by manufacturer or application.

A 12 1/4" OSB SIP with double 2x splines can span about 24' at the most in a generic roof application.