Michael D. Devine

Optimization models for the economic design of wind power systems

Abstract This paper presents optimization models for the economic design of large scale wind power systems. Two basic models are introduced: (1) Systems without storage—all power generated is fed directly into the existing network, and (2) systems with storage—the systems are operated as part of base load or peak load capacity. The objective of the models is to maximize the total net value of power generated under assumed operating rules and general conditions regarding wind speed and demand variations. The model for wind power systems without storage is developed to determine the total capacity of wind turbines that vary in the values of design parameters such as rotor diameter, tower height, and rated power. The model for systems with storage uses an analytical storage model as a basis of representing storage requirements. The model is designed for the case of little serial correlation in successively measured wind speeds. It is then modified for the case of a low degree of correlation. Separable programming is used as a solution technique in both models and limited computational results, based on available cost estimates and Oklahoma wind and demand data, are presented to illustrate the use of the models. In the first model, separable programming will yield a globally optimal solution for certain types of cost functions used. However, in the second model, the problem structure is such that a global optimum cannot be guaranteed.

An analysis of solar heating systems that use vapor-compression cycles

Abstract This paper analyzes the technical and economic performance of solar heating systems that use vapor-compression cycles, circulating a compressible fluid as the working fluid. With conventional solar heating systems that use water or as their working fluid, the collector inlet temperature is equal to that of the storage outlet temperature. Operating the system on a cold day can result in large thermal losses to the surroundings and, thus, low useful heat gains. A vapor-compression cycle may be attractive because it allows the collector inlet temperature to be lowered so that the heat gain of the collector can be increased. Such a system is simulated and a preliminary economic analysis performed. The results indicate that the vapor-compression system can collect almost 50% more solar energy than a conventional system if the collector area of the two systems are the same.

A time-sharing interactive program for class scheduling

Abstract The purpose of this paper is to describe a time-shared class scheduling program that has been implemented and used for the past three years by the Oklahoma City Public Schools. The program uses heuristic procedures in an attempt to minimize student conflicts in a “modified modular scheduling” environment. In addition, the program is interactive so that the scheduler takes an active role in the scheduling decisions.

A Dynamic Programming Approach to a Bidder Selection Problem

Abstract This paper deals with a set of combinatorial decision problems that arise in large-scale governmental or military procurement operations. After stating the problems, they are then mathematically formulated as linear integer programming problems. However, because a specified sensitivity analysis is required, a dynamic programming approach is shown to give all solutions needed after one pass through the DP tableaus. A model has been implemented and is currently being used by a large buying activity of the Department of the Army.

Energy from the western states of the USA: conflicts and constraints

Abstract Large-scale energy resource development in the western states will almost certainly be required if the USA is to increase its domestic energy production significantly. Such development will create several problems, including conflicts over water use and quality, air quality, growth management and housing, and land use. In this article the authors discuss each of these issues and the kinds of trade-off which can be expected if certain policies are chosen. Although there are several promising strategies for realizing the benefits of development while minimizing environmental and socioeconomic costs, their success is likely to be limited by serious institutional constraints. These constraints ultimately block much energy resource development in the western states.