Distributed generation as a balancing resource for wind generation

Full exploitation of the environmental and financial benefits of wind-generated energy in a power system requires prediction of the wind energy profile well in advance of delivery. On the basis of forecast profile and associated confidence, wind energy can be included in the unit commitment/economic dispatch procedure, resulting in near-optimal commitment and loading of thermal plant, thereby saving fuel. A wind forecasting methodology, which closely resembles a commercial wind forecasting package, is adopted to illustrate the possible instances of significant over-forecasting, although rare, and exposure of the system to substantial risk. It is shown that the cost of additional spinning reserve necessary for such cases is prohibitive, and a fast, flexible generation, such as diesel gen-sets are considered as a superior mechanism to balance any such shortfalls. The Northern Ireland power system is used as a case study to demonstrate the environmental and financial benefits of using distributed diesel generation in the manner described above. The study is based on a six-month period system data, and is applied to various future scenarios of the installed wind. It is shown that the methodology can mitigate many of the problems associated with large-scale wind penetration on a synchronously islanded system.