2016 NGWA Groundwater Summit

Feasibility Evaluation of Using Open-Loop Ground Source Heat Exchange in a Coastal Aquifer

Wednesday, April 27, 2016: 2:30 p.m.
Confluence Ballroom A (The Westin Denver Downtown)
Min-Ying Chu, Ph.D., PE , Haley & Aldrich, Inc., Oakland, CA
Murray Einarson, P.G., C.E.G. , Haley & Aldrich, Inc., Oakland, CA
Tylor Ketron , Haley & Aldrich, Inc., Oakland, CA
Jim Bererton, P.Eng , Integral Group, Inc., Oakland, CA

The ongoing California drought continues decreasing hydropower generation and increasing power generated by natural gas. Because energy use in residential, commercial and institutional buildings account for a significant portion of energy consumption and carbon emission in California, an energy efficient measure to service various heating and cooling loads of a building is desirable. It has been recognized that use of ground source heat exchange (GSHE) systems has great potential in reducing carbon emissions, enhancing water conservation, and providing cost saving relative to traditional heating and cooling methods. In this presentation, we describe an integrated approach to evaluate the feasibility of a possible open-loop GSHE system for a mixed commercial and residential development project in the San Francisco Bay area.

The open-loop GSHE system was assumed to use groundwater recirculation to meet all cooling and heating demand. The hydrogeological framework of the study area was based on published literatures and review of more than 60 water wells and borings in the study area. The groundwater flow field and thermal transport was evaluated using the MODFLOW and MT3D modeling tools under different recirculation configurations. To account for the thermal energy interaction between the injection and extraction wells, the injected groundwater temperature was based on time-dependent thermal loading and simulated extracted groundwater temperature. The projected magnitude and pattern of heating and cooling demand were repeated for 12 years to evaluate the long-term system performance.    

The system feasibility was assessed using the following criteria: (1) ability to service the peak thermal load, (2) ability to maintain the temperature of extracted groundwater within the range of effective heat exchange, and (3) possible thermal impacts to groundwater receptors as thermal energy migrates away from the site.

Min-Ying Chu, Ph.D., PE, Haley & Aldrich, Inc., Oakland, CA
Dr. Min-Ying Jacob Chu is a Senior Engineer at Haley & Aldrich, Inc. His expertise includes groundwater modeling, vadose zone transport processes, environmental microbiology, remedial system design, and system behavior evaluation. He has published numerous journal articles in the topics of reactive transport modeling, mass transfer, and bioremediation. Dr. Chu has a Ph.D. in Environmental Science and Engineering from Stanford University. He received his Master of Science degree in Environmental Engineering from Oregon State University and earned his Bachelor of Science degree from National Taiwan University.

Murray Einarson, P.G., C.E.G., Haley & Aldrich, Inc., Oakland, CA
Mr. Einarson has 30 years of experience in the development, testing, and application of innovative approaches and technologies for cost-effective environmental site characterization and in-situ remediation. He has been an instructor in the Princeton Remediation course and the University of Waterloo graduate course in field hydrogeology for the last 10 years. Mr. Einarson has provided technical training in subsurface characterization and groundwater monitoring for Regional Water Quality Control Board staff every year for the last five years. He is also a recipient of the Ground Water Technology Award from the National Ground Water Association in 2009.

Tylor Ketron, Haley & Aldrich, Inc., Oakland, CA
Tyler Ketron is a hydrogeologist with Haley & Aldrich in Oakland, California. He has a B.S. and a M.S. in Earth Systems from Stanford University. His professional work focuses on numerical modeling, innovative data visualizations, and geospatial analysis.

Jim Bererton, P.Eng, Integral Group, Inc., Oakland, CA
Jim Bererton is an energy innovator with Integral Group, Inc. His expertise is across a wide-range of technologies, including waste heat, recovery, solar thermal, photovoltaics, biomass, geothermal, wind turbines and sustainable building design. His work at Integral Group focuses on renewable energy and water systems for large district-scale projects.