With REF the system efficiency, stability and reliability could be obtained, as with high REF the system would be more stable in voltage, frequency giving better regulation and efficiency with working power factor near to unity…..
As in old methods for load flow and contingency analysis as the in system industrial and domestic solar and wind power with battery back are not considered, though is badly needed to be considered, with involvement of solar and wind powered generating stations in systems load area…..
Well in optimization you need to cater the load with mixed generation considering all possible constraints, battery schedules (charge/discharge) are important so if battery is getting charged by renewable generation then it is the quantities are important, i.e. what fraction of RER generation is required to be directly dispatched? What fraction of RER generation can be utilized to charge the battery and at what time? When to discharge the battery.