Geothermal: Digging Beneath the Surface

Geothermal energy is potentially the largest source of energy in the world today - with volumes vastly more than the global total of oil and natural gas combined. Geothermal is renewable and will most likely last for billions of years. Its carbon footprint is minimal. It is stable. We can predict the power output of a geothermal power plant with remarkable accuracy. Geothermal power plants can produce electricity consistently, running 24 hours a day, 7 days a week, regardless of weather conditions. Actual power output is very close to total installed capacity. Yet, current global geothermal energy use lags far behind other energy sources, comprising only 1% of overall energy production. A study by the US Geological Survey concluded that at least 70% of global geothermal resources have yet to be discovered. And they exist throughout the world. Failure To Launch So why has the vast potential of geo-thermal energy remained substantially untapped? Numerous answers have been put forward. Some say that until recently it has been a straightforward business calculation. With hydrocarbons incumbent and prices comfortably high, what would be the business rationale for diverting resources - human, technological, and otherwise - to an energy resource that hasn’t proved its value? Ignorance and misunderstanding also play a role. “For a vast majority of the population, if you ask about wind and solar, most understand what the resources are and what their value proposition is,” said Vikram Rao, executive director of the Research Triangle Energy Consortium and former vice president and chief technology officer of Halliburton. “If you ask about geothermal on the other hand, most people think of Iceland, Yellowstone, and heat pumps.” There is confusion among the general public, even among smart practitioners in the energy transition space, as to what geothermal energy is. Geothermal ground-source heat pumps used to heat individual homes are not the same as the generation of power by geothermal on an industrial scale. Geothermal’s slow progress recalls the oil and gas industry of the early 1900s when only a fraction of the resource could be tapped with the then-existing technologies, and only in areas where “black gold” and other obvious signs of oil and gas existed at the surface and could be developed. Geothermal energy development over the past century has evolved in much the same way. Geysers, steam vents, hot spots, and other obvious surface signs of geothermal energy have been developed, but the resources that are not visible have been largely ignored because of heavy upfront costs. “Conventional, hydrothermal (steam) geothermal energy today comes from places where, by chance, the right conditions - heat, permeability, and the presence of substantial amounts of water - all occur naturally very close to the surface. And looking at Earth’s total landmass, the number of places where those unique conditions occur is incredibly small,” Rao said. In the past, that imposed severe geographical limitations on the resource and quashed interest. As a result, geothermal has been largely absent from the public energy debate, energy policy discussions, and strategic plans of major energy companies.