NSF R2I2: Enhancing Northeast resilience through innovations for deep geothermal heat direct use

The Northeast United States is struck with high-frequency and low-predictability frigid winter days, scorching heatwaves, and flash floods. This project aims to develop the simulation tools, partnerships, and collaboration networks necessary to create an incubator for Enhanced Geothermal Systems (EGS) for direct geothermal energy use – primarily towards district heating and cooling. With its infrastructure mostly deep underground and a local energy distribution network, EGS for direct heat use is not vulnerable to floods. In contrast to intermittent wind and solar energy, geothermal district heating and cooling are fully dispatchable as they do not require energy storage. Geothermally useful formation temperatures are regionally ubiquitous and accessible, making EGS technology a viable option to alleviate increasing demands on the electricity grid for heating and cooling. Indeed, EGS for direct district heating could satisfy heat demand of about 45 million U.S. households, and EGS-based resources are theoretically sufficient to heat every U.S. home and commercial building for at least 8,500 years. With input from various established partnerships, the models developed in this project will quantify the performance of the EGS technology to determine the engineering, environmental, and economic metrics needed for scalable deployment in the Northeast. A novel geothermal reservoir model will support a feasibility assessment for EGS district heating in the Northeast of the U.S., where subsurface temperatures are significantly lower than in the West at similar depths. Outcomes include models of highly anisotropic rock with fractures interacting at multiple scales; validated models of pressurized fracture propagation in the presence of natural discontinuities; and risk assessment for induced seismicity during reservoir stimulation. Additionally, energy recovery and thermal drawdown will be rigorously estimated for various underground infrastructure designs, integrated heat pump systems, and EGS operational conditions. Partnerships will be developed to model the economic potential of geothermal direct heating in the Northeast, incorporating the full costs and benefits of EGS in comparison to baseline heating sources. Compared to prior models, the proposed project will consider a larger area, higher resolution data, and updated assumptions regarding energy consumption and heating, natural gas and electricity prices, the cost of capital, and federal and state policy incentives. A transformative approach will be adopted to integrate estimates of the economic value of avoided externalities, and to develop levelized costs of heat directly produced by EGS. 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.