Techno-economic analysis of geothermal system in residential building in Memphis, Tennessee

Abstract

The residential building sector in the United States relies prolifically on electric cooling and natural gas heating, ventilating, and air conditioning systems. Technology advancement for more energy efficient and cost-effective energy systems is continuous, and a geothermal energy system is an attractive alternative to electricity and natural gas. This study investigates a simulated residential building in Memphis, Tennessee (TN) to assess the energy savings by replacing the existing electric/gas system with a geothermal heat pump system. Further, economics are considered to examine the payoff period and ultimate viability for geothermal technology in this region. EnergyPlus™, the U.S. Department of Energy (DOE) whole building simulation engine, analyzed a prototype home in Memphis, TN with this common utility system. City-specific ground characteristics are used to customize the ground heat exchanger and optimize result accuracy. Simulations reveal that replacing the existing system with a geothermal system accomplishes a 26% reduction in energy use. Our results prove an exciting alternative for homes in Memphis, TN to achieve abundant energy savings. Despite lower meter readings, a homeowner must consider initial capital investment and payoff period. This study provides city-customized payoff data by using local ground characteristics for design, location-specific home features, and regional plus federal incentive programs. Methods used within create a unique and accurate template procedure for identifying promising regions for residential geothermal systems throughout the broader United States.