Groundwater Flow and Heat Transport Simulations to Evaluate the Potential Impact of Geothermal Energy Production on Hot Springs

Geothermal energy is an attractive alternative to fossil fuels because it is sustainable, supplied continuously, and has a minimal carbon footprint. Where subsurface temperatures are significantly warmer than surface temperatures, heat from the subsurface can be extracted for use at the Earth's surface. The viability of geothermal resources depends on the temperature relative to the surface temperature and on the ability to bring the heat to the surface. In some areas, water carries heat to the surface in the form of thermal springs. In other areas, wells are drilled into the deep, hot rock to extract thermal energy. The state of Colorado contains 49 distinct thermal regions that consist of thermal springs or wells. Historically, these geothermal resources have been considered suitable only for small direct-use applications. Recently, however, the use of these geothermal resources for electricity production has been considered. Many of the thermal springs in Colorado are used for recreation, including well-established resorts such as Glenwood Hot Springs Resort, which has been operating for over 130 years. An unanswered question is whether larger-scale geothermal development will lead to cooling of the recreational thermal springs, negatively impacting the industry. This work uses groundwater flow and thermal transport modeling, respectively, to evaluate the potential impact of geothermal energy production on surficial hot springs.