The fourth part focuses on the analysis of options to meet the three concurrent objectives of security, cost and sustainability through curtailing emissions. It discusses the shortcomings of some of the market mechanisms and the regulation that has been applied to meet them. A set of scenarios is developed to provide a framework for analysis based on the use of an overview model developed to embrace the technical operational aspects of system management. It will also draw comparisons with other approaches like the 2050 model. The work concludes with a review of the governance and market arrangements to identify the need for any changes to meet the future requirements resulting from the impending transformation.