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Geothermal: Thermo-Hydraulic Properties of Glacial Tills (In Progress)

Description

Geothermal energy is stored in the Earth that humans can extract, process and then use. It is cost-effective, reliable, and sustainable. Capturing heat from the Earth to run a college campus would lower the U of I’s reliance on fossil fuels and help the university meet the goals set out in the Illinois Climate Action Plan (iCAP).

A borehole located on the John Bardeen Quad, south of Grainger Library, and monitoring station was constructed in late 2018. It contains fiber-optic cable that will be connected to a distributed system to detect changes in the Earth’s thermal profile. This 450-foot borehole will collect data to determine if geothermal movement is viable in this location.

Purpose of the Work: Campus Connection

Using iSEE seed funding in early 2019, researchers are using the site for investigating the effect of temperature on hydraulic conductivity of glacial tills (heterogeneous subsurface geomaterials). They will collect core samples from the borehole west of the geothermal exchange field on the Bardeen Quad and perform lab tests on the samples under representative field conditions to characterize conductivity and elevated temperatures.

Continued Research at Ven Te Chow Lab

In Spring 2019, it was announced that geothermal energy foundations will be installed at the new portion of the Ven Te Chow Hydrosystems Laboratory. The new $240,000 project was funded by the Student Sustainability Committee (SSC) and the campus Carbon Credit Sales Fund administered jointly by Facilities & Services (F&S) and iSEE. Baser and F&S Executive Director Mohamed Attalla are the Principal Investigators for this project.

Experiments on this innovative method of reducing greenhouse gas emissions incorporates conventional geothermal heat exchanger loops in foundations under the iconic bridge, to reduce installation costs. These 50-foot-deep drilled shaft foundations will include geothermal heat exchangers, configured to exchange thermal energy with adjacent subsurface soil. During installation, Baser will instrument the drilled shafts with thermistors and strain gauges to measure the axial and radial strains as well as temperature profiles within the piles. The data set from this installation will enable the evaluation of operational thermo-mechanical properties of the piles. Further, the data collected will be used as an input for analyses at the graduate-level CEE 585 Deep Foundations course. 

Lessons learned from this installation will provide an opportunity for researchers to conduct a scalability study — and a basis for fundamental understanding of the operational response of the energy foundations.

Background

Background: Previous Geothermal Efforts

In 2016, funded by the Student Sustainability Committee (SSC), Illinois State Geological Survey (ISGS, a Division of the Prairie Research Institute) researchers Yu-Feng Forrest Lin and Andrew Stumpf installed a test geothermal well on the campus south farms to study the potential of using ground source heat pumps at a large scale to meet campus heating needs and reduce campus fossil fuel reliance.

A borehole located on the John Bardeen Quad, south of Grainger Library, and monitoring station was constructed in late 2018. It contains fiber-optic cable that will be connected to a distributed system to detect changes in the Earth’s thermal profile. This 450-foot borehole will collect data to determine if geothermal movement is viable in this location. The 2018 project, also funded by SSC and led by Lin, Stumpf, Baser and CEE Professor Timothy Stark, was an extension of ongoing research into implementing geothermal energy on campus. The monitoring station remained active throughout the time period the geothermal system is used. Temperature data was continually collected from the fiber-optic cable while the geothermal system was in use.

Project Team

  • Project Leader:

    Tugce Baser, Assistant Professor, Civil and Environmental Engineering

    Team Members:

    • Co-PL: Roman Makhnenko, Assistant Professor, Civil and Environmental Engineering
    • Co-PL: Andrew Stumpf, Geologist, Illinois State Geological Survey

Themes