Is Geothermal Energy a Good Alternative to Powering the Planet?

It has been estimated that within the continental United States there is a sizable resource of accessible geothermal energy, which could supply about 3,000 times the current annual U.S. consumption. With fossil fuel sources depleting and global warming on the rise, exploring alternative means of powering human civilization is becoming of dire importance.

But now researchers are saying that it’s not just the sky via wind harnessing, or various forms of water power that offer hope. There is another clean, renewable energy source that is being largely overlooked: deep within Earth is an untapped source of abundant geothermal energy.

One major reason this storehouse of energy has not been tapped is that locating these energy hot spots is difficult, time-consuming and expensive.

“Since many geothermal resources are hidden, that is, they do not show any clear indications of their presence at the surface, locating them by just using observations made at the surface is difficult,” explains researcher Matthijs van Soest of Arizona State University. “Often when people thought there might be a geothermal resource below the surface the only way to determine if their assumption was correct was drilling and drilling is extremely expensive,” he says.

Now a new breakthrough is poised to radically alter the prospects of geothermal energy exploration.
Van Soest and B. Mack Kennedy of Lawrence Berkeley National Laboratory have found that an effective new method of geothermal exploration may not require any drilling at all.

Helium-3, whose nucleus has just one neutron, is made only in stars, and Earth's mantle retains a high proportion of primordial helium-three (compared to the minuscule amount found in air) left over from the formation of the solar system. Earth's crust, on the other hand, is rich in radioactive elements like uranium and thorium that decay by emitting alpha particles, which are helium-four nuclei. Thus a high ratio of helium-3 to helium-4 in a fluid sample indicates that much of the fluid came from the mantle.

“We wanted to show that certain surface indicators, specifically the ratio of helium isotopes, can be used to identify areas with high resource potential for geothermal energy,” says van Soest, co-author of a research report that appeared in the journal Science.

This incredible discovery that leftover stardust can provide a relatively cheap and fast method of locating geothermal energy without drilling makes this form of energy a much more viable option. With exciting new discoveries, such as this one, surfacing daily—soon there won’t be many good excuses left for not powering the planet through means that aren’t simultaneously destroying it.

Posted by Rebecca Sato