A High Level Geothermal System Scoping Model: A First Step Toward Enhanced Geothermal Systems Engineering

Abstract

Within the field of geothermal power, the fields of well construction and engineering, power plant construction and engineering, and reservoir engineering often proceed independently of one another, and progress and results from one area do not necessarily inform the activities in another. Yet in any geothermal power plant, the surface facility interacts with the wells, and the wells interact with the reservoir, so clearly there is also an interaction between the power plant and the reservoir that is mediated by the wells.

These areas need to be integrated in order to make enhanced (or engineered) geothermal systems (EGS) a technical and an economic reality. In a collaborative effort between the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL), a high –level model is under development that uses a lumped-parameter approach to examine the interplay among the several subsystems of a putative geothermal system– power plant, wells, and reservoir. The goal of this effort is to provide a basis for performing a variety of trade-off analyses and systems engineering studies in order to better inform R&D direction and investment for geothermal systems. This effort complements activities ongoing at SNL to develop a more detailed model of heat and mass transfer within the reservoir and to more fully describe geothermal systems dynamics.