On the Optimal Rate of Geothermal Energy Extraction

Abstract

A geothermal reservoir is, among other things, a stock of heat energy of a given " quality ," stored in an aquifer system. In this study, stock is considered finite and exhaustible over the relevant economic horizon. An important consideration in exploiting this resource is the optimal" rate at which the energy stock should be extracted from a particular geothermal anomaly. This is primarily an "economic" question, although any meaningful conclusions on an optimal extraction, based on a specific model of the physica hydrothermal processes that occur in the geothermal aquifer. extraction policy must surely be Accordingly, the purpose of this paper is to outline some economic models for optimal particular hydrothermal model. - in the context of a particular hydrothermal model.

The discussion focuses on one anomaly. The rate of hydraulic pumpjng is the major decision variable, and the analysis trades of f discounted 'ivalw" of energy from the anomaly against the rate of deterioration of the quality (temperature) of the heat stock. All extracted fluid is recycled, and no divergence between private and social benefits and costs is assumed. Secondary or indirect regional benefits and costs associated with development are not considered.