Background

Since the release of Duke’s first Climate Action Plan in 2009, campus leaders have been working to develop sustainable solutions to a range of campus operations, including campus energy use. To reach the goal of carbon neutrality set out in the Duke Climate Commitment, Duke must consider more sustainable, cost-effective ways to heat and cool water, which according to the Duke Office of Sustainability, accounts for about half of campus energy usage.

Aquifer Thermal Energy Storage (ATES) Systems represent one promising sustainable energy supply for heating and cooling buildings. ATES systems store and retrieve thermal energy from underground water sources by taking advantage of the natural properties of the earth to store excess heat or coolness from buildings or industrial processes for later use.

Project Description

This project team will seek to establish if the rock formations underlying Duke’s Central Campus can be used as local Aquifer Thermal Energy Storages to cool and heat Duke and Durham buildings.

This work will build on exploratory drilling that has already begun. In Phase I of this project, a 352-foot deep borehole was drilled in Central Campus. The bottom 20 feet of this well penetrated fractured Carolina terrane basement rocks that appear to underlie campus and potentially the Durham area. If these water and fracture-rich rocks extend tens of feet deeper and are highly permeable, they may have potential for storing cold water for cooling and hot water for heating.

The goal of Phase II of this project is to establish both the useful thickness of the potential ATES rocks and their capacity for cost-effective energy storage. The Phase II borehole will also illuminate the potential for carbon dioxide storage. To this end, this project will extend the Phase I borehole to 700 ft and characterize its rock for potential cost-effective ATES.

In partnership with the U.S. Continental Drilling Program based at the University of Minnesota, this team will collect measurements and perform characterization in the field on Duke’s Central Campus and at testing facilities at the University of Minnesota. Essential measurements include, for example, assessing porosity, permeability, and thermal properties in the target zone cores; analyzing the water chemistry in the target zone and its reaction; and establishing a minimum background temperature profile and background temperature change-rates.

Anticipated Outputs

Estimates of the cost-effective ATES capacity of the fractured basement rocks to assess the continued viability of this solution; publications

Student Opportunities

Ideally, this team will include 15-20 graduate/professional students and 5 undergraduates with skills and interests in earth science, geochemistry, environmental engineering, geology and civil engineering.

Students on the team will obtain real world experience in energy resource characterization and optimization. Students will do hands-on material characterization of the extracted core samples and will learn about resource design and optimization. 

During academic breaks, students will also have the opportunity to travel to National Energy Technology Laboratory and Continental Drilling Program facilities in West Virginia and Minnesota, respectively, to conduct lab assessments. Students may also have the opportunity to contribute to research publications.

In Fall 2023, students on this team must enroll in the half-credit course ECS 590-01/CEE 690-07: Geothermal Topics and Practice to participate. The course will meet on Tuesdays from 3:05 to 4:20 p.m. 

Students will be provided with a similar enrollment option for Spring 2024.

Timing

Fall 2023 – Summer 2024

• Fall 2023: Characterize core-logs; process data from in-situ sensors 
• Spring 2024: Install new sensors; characterize core-logs; process data from in-situ sensors
• Summer 2024 (optional): Continue analysis and characterization; prepare publications and findings

Crediting

Unlike other Bass Connections projects, students do not need to submit an application to join this team but must instead directly enroll in ECS 590-01/CEE 690-07 Geothermal Topics and Practice for Fall 2023 (half-credit course). Participation will be on a first-come basis. This is an advanced undergraduate/graduate level course and is only open to juniors, seniors and graduate students. Students will be provided with a similar half-credit enrollment option for Spring 2024.