Energy Independence Investment Act of 2015 This bill requires the Department of Energy (DOE) to study and report on the effectiveness of the advanced fossil loan guarantee incentive program and other DOE incentive programs for advanced fossil energy. In carrying out the study, DOE must: solicit industry and stakeholder input; evaluate the effectiveness of the advanced fossil loan guarantee incentive program in advancing carbon capture and storage (CCS) technology; review each incentive provided by federal agencies for CCS demonstration projects to determine the adequacy and effectiveness of the combined federal incentives in advancing CCS and advanced fossil energy technologies; assess whether combinations of existing incentive programs could be effective to advance CCS and advanced fossil energy technologies; and evaluate the impact of implementing the recommendations described in the January 2015 National Coal Council report entitled, "Fossil Forward: Revitalizing CCS, Bringing Scale and Speed to CCS Deployment," on the effectiveness of the advanced fossil loan guarantee program.