Evaluating Opportunities For Enhanced Geothermal System-Based District Heating In New York And Pennsylvania
Enhanced Geothermal Systems (EGS) have the potential to supply a significant fraction of the low-temperature (<125°C) thermal energy used in the United States, and Geothermal District Heating (GDH) networks provide the primary means for distributing and selling that energy. To encourage wider discourse about utilization of low-temperature geothermal resources, the potential for EGS district heating in the U.S. states of New York and Pennsylvania was evaluated. Opportunities were evaluated on two levels. First, geographic locations and towns with the most promise for GDH were identified as the best communities for initial feasibility studies and future GDH deployment. Second, factors contributing most to the cost of EGS district heating were identified as possible targets for research and development (R&R) efforts. In order to evaluate these opportunities, a model was developed to simulate an EGS district heating system at every population center within the study region. Incorporating an updated geothermal gradient map, buildings and energy census data, an EGS district heating model, and investment and operation and maintenance costs, a unique levelized cost of heat (LCOH) from GDH was estimated for each community. These LCOHs were compiled into a supply curve and used as the primary metric with which to compare GDH systems across the region and identify the most promising communities in which to focus initial GDH efforts. An analysis of the sensitivity of the LCOH to various model inputs provided a means to identify the factors with the most influence on LCOH and thus pinpoint the most effective technology components to target with research and development efforts in order to reduce the cost of GDH and increase its ability to compete with more traditional heating methods. Further, three separate technology cases were evaluated in order to investigate the capabilities of EGS district heating given both the state of the technology today and its potential in the future given improvements to EGS technology. It was found that EGS district heating certainly has the potential to supply clean, reliable, costeffective energy for space and water heating for New York and Pennsylvania in the near future. However, modest improvements in EGS technology, escalation of current natural gas prices, or some form of government incentive will likely be required before GDH is able to compete with other heating alternatives today on purely economic grounds. EGS reservoir flow rates, drilling costs, system lifetimes, and fluid return temperatures have significant effects on the LCOH of GDH and thus will likely provide the highest return on R&D investment.
District Heating; Geothermal Energy; Levelized Cost
Tester, Jefferson William
M.S. of Geological Sciences
Master of Science
dissertation or thesis