Long Range Generation Planning With Limited Energy and Storage Plants Part I: Production Costing

Generalized Benders´ decomposition has been proposed as the basis for a new model for long range generation planning integrating linear programming with probabilistic methods for production costing and reliability calculations. The original formulation of this model is suitable only for power systems in which all generators are of the thermal type, which can produce unlimited energy. In modeling real utility systems, it is often necessary to include limited energy plants and storage plants. Modeling these technologies requires modifying both the master problem and the subproblems of the generalized Benders´ model. The production costing subproblems require extensive changes, particularly to determine the proper loading order positions for plants of these types and to implement new formulas to compute the dual multipliers. Significant advances in this work include the discovery of energy invariance properties which reduce substantially the computation required and a new treatment of the manner in which charging storage units modify the equivalent load duration curves. Modifications of the production costing subproblem are described in this paper. A sequel, Part II, describes the modifications necessary in the master problem linear program.