SAM's geothermal power model is based on the U.S. Department of Energy's Geothermal Electricity Technology Evaluation Model (GETEM), https://energy.gov/eere/geothermal/geothermal-electricity-technology-evaluation-model. The model calculates the annual and lifetime electrical output of a utility-scale geothermal power plant, and the levelized cost of energy and other economic metrics for the plant.
SAM cannot model a ground source heat pump (also called geothermal heat pump or geoexchange) systems for building heating and cooling.
Documentation for the U.S. Department of Energy's Geothermal Electricity Technology Evaluation Model (GETEM) is available from https://energy.gov/eere/geothermal/getem-manuals-and-revision-notes.
The geothermal power model calculates the output of a power plant that uses heat from below the surface of the ground to drive a steam electric power generation plant. SAM analyzes the plant's performance over its lifetime, assuming that changes in the resource and electrical output occur monthly over a period of years.
SAM can be used to answer the following kinds of questions:
- What is the levelized cost of a geothermal power plant, given a known configuration and resource?
- How does changing the design of the plant affect its output and levelized cost of energy?
- What plant size is required to meet an electric capacity requirement?
- Given a known number of wells, what would the plant's electric capacity be?
SAM models the following types of systems:
- Hydrothermal resources, where the underground heat reservoir is sufficiently permeable and contains sufficient groundwater to make the resource useful without any enhancements.
- Enhanced geothermal systems (EGS) that pump water or steam underground to collect heat stored in rock. These systems involve drilling or fracturing the rock to improve heat transfer. Over time (typically years), as heat is collected from the rock, its temperature decreases, and more drilling is required. SAM's recapitalization cost accounts for the cost of these improvements to reach new resources.
- Both flash and binary conversion plants.
