District Geothermal Heating Using EGS Technology to Meet Carbon Neutrality Goals: A Case Study of Earth Source Heat for the Cornell University Campus

Many states in the U.S. are adopting mandates and regulations to significantly lower their carbon footprints as well as increase their use of renewable energy. Most of these policies focus on using renewables for generating electricity and electrifying land transportation, yet they ignore the need for thermal energy. However, in almost half of the U.S. states ― most of them in the Northern Tier region ― over 20% of total statewide end-use energy demand is for thermal applications, predominantly space and water heating in the residential and commercial sector. This heat demand is mainly supplied by burning fossils fuels, however, lower temperature geothermal resources (<150°C) could provide an attractive, low-carbon alternative. Unlike high-grade resources, which are concentrated in the western U.S. and have been the focus of geothermal development ― mainly for electricity production ― lower temperature resources are widely available throughout the country. They include hydrothermal reservoirs, sedimentary aquifers and deep Enhanced Geothermal Systems (EGS) in low-permeable, crystalline rock, and can all be categorized under Earth Source Heat (ESH). Cornell University in New York State is attempting to use ESH to provide geothermal baseload heating as a key component of its strategy to reach carbon neutrality for its campus of 30,000 people. Project research and analysis is ongoing ― an update of which is presented in this paper ― and includes (1) characterizing the subsurface (using data obtained from regional core logs, bottom-hole temperature measurements, and stratigraphic columns, outcrops in the Adirondacks Mountains, and local active seismic, passive seismic, magnetic, and gravity surveys), (2) performing reservoir simulations, (3) reviewing optimal integration into existing campus district heating system, (4) site-selection for an initial exploratory well on campus, and (5) assessing required capital investment and overall levelized cost of heat. A successful Cornell ESH demonstration project could serve as example for rural and urban communities in New York State and the Northern Tier of the U.S., where annual heating loads are high and low-temperature geothermal resources are widespread.