Structural Analysis of a Hot Dry Rock Geothermal Energy System
Bennington CollegeAuthor Profile
This project applies basic geologic skills to the development of a geothermal electrical generation system. I use it in a structural geology, but it would be applicable to any intermediate to advanced level course to teach three-dimensional structural analysis and rock fracturing.
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Could be used for an undergraduate course in Structural Geology or Engineering Geology
Skills and concepts that students must have mastered
Students must understand and be able to use Mohr's circles to calculate stresses, use the Mohr-Coulomb failure criteria to assess hydrofracturing of rock, construct simple cross sections, and perform three point problems.
How the activity is situated in the course
I use this as a stand-alone exercise. It could also be used as a laboratory exercise.
Content/concepts goals for this activity
This activity attempts to make students to apply skills learned across a large portion of a basic structural geology course to a single energy-based project. The skills include geologic interpretation of structural deformation, analysis of rock strength, and fracture systems.
Higher order thinking skills goals for this activity
This activity should help students build three dimensional analysis and quantitative reasoning skills.
Other skills goals for this activity
Reporting of results will help students develop technical writing skills.
Description of the activity/assignment
This project applies basic geologic skills to the development of an alternative energy project. The project starts with an interpretation of the basic geology of the site, which is a simplified geologic map of the Front Range structures near Golden, CO. Students are required to construct a cross section and determine the depth of an initial bore hole. They then analyze stresses in that hole for hydrofracturing, and predict the geometry of produced fractures. The final part of the project is to perform three point problems to calculate the depth that the fractures will be encountered at two additional boreholes. There is also a writing component to the project in the reporting of results.
Determining whether students have met the goals
I evaluate the activity dominantly on whether or not the student was able to successfully design the system to achieve interconnected boreholes for water circulation.More information about assessment tools and techniques.
Teaching materials and tips
- Activity Description/Assignment: Structural Analysis of a Hot Dry Rock Geothermal Energy System Exercise (Acrobat (PDF) 268kB May11 09)