On Cornell Engineering Week: A solution to heating our homes more efficiently may be right under our feet.

Chloe Arson, professor of Earth and Atmospheric Sciences, digs down to explore.

Chloé Arson is a professor in the Department of Earth and Atmospheric Sciences at Cornell University with expertise is damage and healing rock mechanics, micro-macro modeling of porous media, and computational geomechanics. Her research group develops numerical tools to assess the performance and environmental impacts of underground storage and rock fracturing, explain the formation of soil by rock weathering, and design sustainable bio-inspired geotechnical systems. Arson’s latest line of research investigates the use of artificial intelligence to optimize subsurface exploration and enhance multi-scale geomechanical models.

You may be familiar with homes being conditioned by geothermal energy, using shallow heat pumps that circulate pipes a few hundred feet underground to warm buildings in winter and cool them in summer. But that’s just scratching the surface.

Deeper underground, the Earth gets hotter – a steady rise called the geothermal gradient. Those higher temperatures open up new possibilities for supplying heat to multiple buildings or even industrial facilities – things shallow geothermal systems can’t do. That’s where deep geothermal systems come in. Heat is harvested by drilling kilometers down and circulating fluid through fractures in the hot rock. When the subsurface is not permeable enough to circulate the fluid, it is possible to build an Enhanced Geothermal System, or EGS for short. “Enhanced” means that the rock is stimulated to open or create fractures prior to operations. The EGS technology makes it possible to harvest heat nearly anywhere.

In Utah and Nevada, two-mile-deep enhanced geothermal systems have produced electricity. In the eastern U.S., the rocks are about three times less hot at similar depth, which is not economically practical for power generation, but is ideal for heating buildings directly. Cornell University recently drilled a two-mile-deep borehole to assess the feasibility of EGS for direct heat production, but many challenges to deploying this type of system still exist.

The economic potential for direct heat-generating enhanced geothermal systems is on the order of 320 gigawatt-thermal units in the United States, enough to heat about 45 million households. Clean, renewable heat is beneath our feet. The challenge now is to build the infrastructure.

Read More:Earth Source Heat - Cornell University

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