A system tool merges different load forecasts for power grid centers. A plurality of load forecast engines are coupled to a load forecast interface and a relational data base that saves load forecast engine data as an input through the load forecast interface. A comprehensive operating plan is coupled to the load forecast engines and the relational database. The comprehensive operating plan is configured to integrate individual load forecasts into a composite load forecast to present a comprehensive, synchronized and harmonized load forecast. A program interface provides access to the composite load forecasting schedule.