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Illinois State Geological Survey receives DOE grant for geothermal study

University of Illinois, Urbana-Champaign (source: flickr/ ilovebutter, creative commons)
Alexander Richter 23 Oct 2017

The Illinois State Geological Survey (ISGS) has received a $720k grant to study the feasibility on a deep direct-use geothermal heating and cooling at a campus of the University of Illinois.

As announced today, the Illinois State Geological Survey received a US$720,000 grant from the U.S. Department of Energy to determine the feasibility of tapping geothermal energy for heating and cooling on the University of Illinois’ Urbana campus.

The project, led by ISGS hydrogeologist Yu-Feng “Forrest” Lin, will determine the potential to provide cost-effective, renewable thermal energy from the low-temperature sedimentary basins that underlie large portions of the United States. ISGS scientists will evaluate harnessing the natural heat from two geological formations (the St. Peter and Mt. Simon Sandstones) under central Illinois, a region previously unexplored for geothermal energy.

The ISGS team will test Deep Direct-Use technology to tap heat from low-temperature (90-190 F) subsurface reservoirs. The goal is to replace the conventional heating and cooling system at the Illinois Energy Farmthe 320-acre “living laboratory” where U of I researchers work on developing alternative energy resourcesand other campus buildings. Results of the study could be applicable to other campuses and multi-building industrial, military, and medical facilities overlying the Illinois Basin, according to Lin.

ISGS will evaluate DDU technology that extracts heat from deep reservoirs of water. Using a paired set of wells, water will be pumped to the surface from deep bedrock aquifers, circulated through a thermal exchange system, and returned to the aquifer at a much lower temperature. Geothermal systems using DDU technologies are typically used for space heating and air conditioning, water heating, and refrigeration.

DDU systems differ from conventional geothermal energy systems, which consist of either: 1) several deep wellbores capturing high-temperature fluid or steam that generates electricity with turbines; 2) very shallow wellbores that act as heat exchangers, tapping the constant temperatures in the near surface using ground source heat pumps to supplement existing heating and cooling systems in homes and commercial buildings; or 3) direct-use geothermal systems that provide heat directly (without converting the resource to electricity) in areas with high-quality hydrothermal resources, such as the western U.S.

The ISGS project will include the geologic, engineering, and economic aspects of large-scale geothermal systems applicable to campus and other large energy users, Lin explained. Complex simulations will involve site geology, water extraction and injection, distribution systems, and cascading usage to reuse the heated water over and over, he said.

The University of Illinois was one of six institutions to receive funding from the DOE’s $4 million DDU program. The grant to ISGS will support studies done at ISGS and partners, including the U of I’s Department of Civil and Environmental Engineering, U.S. Army Construction Engineering Research Laboratory in Champaign, and the University of Wisconsin-Madison. Engineering partners in the project are Loudon Technical Services LLC, MEP Associates LLC, and Trimeric Corporation.

Source: Official release by Illinois State Geological Survey