Decision analysis for geothermal energy

Abstract

One of the key impediments to the development of enhanced geothermal systems is a deficiency in the tools available to project planners and developers. Weak tool sets make it difficult to accurately estimate the cost and schedule requirements of a proposed geothermal plant, and thus make it more difficult for those projects to survive an economic decision-making process. This project, part of a larger effort led by the Department of Energy, seeks to develop a suite of decision analysis tools capable of accurately gauging the economic costs and benefits of geothermal projects with uncertain outcomes. In particular. this project seeks to adapt a set of existing tools, the Decision Aids for Tunnelling, to the context of well-drilling, and make them suitable for use as a core software set around which additional software models can be added. We assess the usefulness of the Decision Aids for Tunnelling (DAT) by creating two realistic case studies to serve as proofs of concept. These case studies are then put through analyses designed to reflect project risks to which geothermal wells are vulnerable. We find that the DAT have sufficient flexibility to model geothermal projects accurately and provide cost and schedule distributions on potential outcomes of geothermal projects, and recommend methods of usage appropriate to well drilling scenarios.