Geothermal energy, which pulls hot air from deep in the Earth’s crust to the surface in order to heat our homes and other buildings, deserves a second look in Pennsylvania. It’s been a go-to for humanity since Paleolithic times, when it was used to heat baths; in Ancient Rome, geothermal energy was harnessed for space heaters. The appeal is simple: if the Earth already generates heat, why not tap into that free source of energy wherever it can be found?

A significant draw of geothermal energy is that it isn’t carbon-based. As Pennsylvania producers transition away from oil and gas-based energy, geothermal provides opportunities for energy which doesn’t rely on practices that ultimately hurt the planet. In fact, geothermal energy producers can repurpose abandoned natural gas wells, using those holes dug deep into the ground to access hot air instead of gas.

Pennsylvania doesn’t have a long history of large-scale geothermal projects. Areas in the U.S. where air can be pulled from hot, wet rocks in the Earth’s crust, as in California, have tended to be the go-to spots. Appalachia’s dry, hot rocks didn’t qualify. But innovations might allow for the region to produce geothermal energy. A system similar to a home’s radiator on a large scale would pump water into the ground, where it will heat geothermally. It can then be pumped back to the surface where a heat exchanger can remove the warmth to send to homes and buildings, then send the cooled water back into the ground for another collection of heat. Many of us are already familiar with this type of system, which functions identically to the small-scale heat pumps that cool our refrigerators.

As recently reported in the Post-Gazette, West Virginia University is exploring the possibility of heating their campus with geothermal energy, making use of a gas well at the University’s Marcellus Shale Energy and Environmental Laboratory Project to study the idea. Funding from the U.S. Department of Energy supports the work, and results are promising: initial tests show water pulled from about 7,000 feet down is about 190 degrees Fahrenheit.

In the meantime, geothermal heating is already at work on a smaller-scale in Pennsylvania. In Philadelphia, for example, dozens of buildings use geothermal systems, including the Ronald McDonald House of West Philadelphia. The technology exists, and just needs to be explored and expanded.

The Pittsburgh region has plenty of rocky terrain dotted with holes from abandoned energy collection, experience with gas and oil drilling and collection, and reason to explore new frontiers in energy. Returning to the ancient practice of collecting heat from the ground beneath is a great place to start. A serious exploration of geothermal energy should be on the state’s radar as soon as possible.

First Published: November 24, 2023, 10:30 a.m.