SBIR Phase II: Innovative Advection-Enhanced Geothermal Heat Pump Fieldloop Demonstration

Darcy Solutions Inc., Saint Paul MN

Investigators

Abstract

The broader impact/commercial potential of this Small Business Innovative Research (SBIR) Phase II project focuses on the high costs and greenhouse gas (GHG) emissions associated with conventional heating, ventilation, and cooling (HVAC) methods. HVAC constitutes approximately 48% of building energy consumption representing a significant cost to society. Much of this energy is generated by fossil fuels, resulting in substantial environmental impacts: carbon emissions associated with residential and commercial use are 35.6% of total US emissions. Geothermal or ground source heat pumps (GSHPs) represent the most energy-efficient and environmentally-friendly HVAC solution currently available, however, their high upfront capital costs have significantly slowed their deployment. The innovation in the present project takes a fundamentally different approach to GSHP heat transfer, resulting in reductions of 50% in installation costs and 20% in operating costs compared to conventional GSHP systems, enabling an expansion of the geothermal market. The present project seeks to thoroughly field test and analyze the performance of the GSHP innovation, optimizing the fabrication and installation parameters, and readying it for commercial deployment. This SBIR Phase II project proposes to address the high installation cost and large, disruptive footprint of conventional GSHP systems. The project objective is to demonstrate a compact, cost-effective, easily-deployable, renewable solution for HVAC. The advection-driven GSHP (AGHP) takes advantage of the 4-5 times greater heat capacity of water than rock. Under the present project, AGHP will advance beyond numerical and laboratory analyses to manufacturing and field testing performance under real-world conditions. The research objectives include: 1) finalization of field site, 2) preliminary design and numerical modeling of the AGHP system for a chosen field site; 3) engineering retrofit design; 4) fabrication of the custom designed submersible pump and heat exchanger; 5) installation and testing of the AGHP system; 6) operation, monitoring, and analysis of the performance of AGHP system, including the development of a comprehensive cost, energy use, and emissions model for the AGHP system; and 7) use of the compiled data to estimate the potential for the economic viability of AGHP in various regions of the United States. The anticipated result of this project is a commercially-ready GSHP product with design and installation guidelines for determining the potential for deploying the innovative AGHP system at any given location. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.