This methodology, however, focuses specifically on a third approach. It is designed to determine how efficiently the various fossil fuel units, regardless of their inherent efficiency, are operated as a group. Most fossil fuel based generating units will have the lowest tonnes CO2 per kWh output rating somewhere near full capacity. In addition, there will likely be a relatively large spread, based on age and technology, of the CO2 intensity of various fossil fuel based generating units. Therefore, the decision process used to determine what units are used at what capacity to meet a specific demand will have a significant impact on CO2 emissions. 

Many electricity dispatch systems in the developing world are managed inefficiently. They lack the advanced modern controls, communications and meters that allow for maximizing the efficiency of generation. The overall efficiency of operation of the entire system will be significantly impacted by how the grid’s dispatch system operates. Optimizing an electricity grid’s dispatch system will allow the generating units as a group to operate under closer to optimal conditions thereby increasing the combined efficiency of generation and reducing fossil fuel consumption per kWh produced. In the case of thermal power plants the reduction of inputs can be directly translated into fossil fuels saved per kWh produced. This methodology will define a project boundary of fossil fuel generating units and calculate the net efficiency gains and the resulting fuel savings achieved by better managing the dispatch system and measured at each generation unit.

In a very simplistic example of a project boundary encompassing four fossil fuel generating units of 100MW capacity. At a particular hour of a given day, the demand required of these four plants is 190MWh. If the dispatch system can allow the two most efficient generating units to operate close to 100% capacity rather than having four generating units operating at 50% capacity the same kWh will likely be produced using significantly less fuel. Depending on the CO2 intensity of the saved fuel, this will result in CO2 emission reductions.

Supervisory Control and Data Acquisition (SCADA) systems and associated energy management software (EMS) when utilized in conjunction with a power dispatch system can greatly optimize the operation of the entire system. The data collection and the real time control systems that are typical of modern SCADA\EMS systems can allow operators to utilize an energy management software system to determine and implement the most efficient combination of generation options under every operation condition.

A Supervisory Control and Data Acquisition (SCADA) system provides facilities to monitor and remotely control, from a central dispatch control center, an electric power grid that can include generation, transmission and/or distribution. The SCADA system utilizes powerful computers at the dispatch control center and communicates with smaller station monitoring and control computers at generating plants and substations. The SCADA system can include facilities for real-time remote control and monitoring of the MW loading and MWh production of each generating unit connected to the grid. Energy Management System (EMS) application software programs can be added onto a SCADA system to provide a variety of advanced features, including Generation Management Systems (GMS) that can significantly improve the efficiency of operation of the various generating units on the grid. The GMS can include load forecasting, generating unit commitment, economic dispatch and hydro/thermal optimization features, each of which contributes to improved efficiency and reliability of real-time generation operations.