Geothermal Energy: Investment is needed to develop new technology

To go faster and deeper requires advances in drilling technologies.

Companies are developing drilling tools that are more stable when breaking through hard rock at high temperatures.

Some companies are considering getting into rock without using standard practices.

The Massachusetts Institute of Technology (MIT)-based Kuez company is using a technology called millimeter wave drilling. The frequency is the same as a microwave oven.

The Quays application involves sending electromagnetic waves in the microwave millimeter wave spectrum to essentially melt and vaporize the rock, explains Quays Communications Manager Harry Kelso.

Traditional geothermal energy clusters around hot spots on the Earth’s surface where very hot rocks are easily accessible.

“Millimeter wave drilling can actually access the hottest geothermal areas anywhere in the world,” says Kelso.

While Quaesz plans to use some conventional drills at the project site in Oregon, Kelso said, conventional drills quickly begin to break when they reach very hard rock.

Drill bit replacement increases the cost and drilling time.

In the case of Quays, Kelso says, “Millimeter wave drilling really changes because we’re not a physical drill.”

Other companies are also working on advanced drilling technology, such as projects that travel several times the speed of sound.

Another important resource in the process is water. While some types of next-generation geothermal can pose a risk of water contamination or over-drinking, careful design can avoid this problem.

Initially, the quay system requires a lot of water, but Kelso says, once the water is in the system, it continuously circulates over the hot rocks.

“We’re essentially recycling the water over and over again,” he says.

Quez continues to raise funds, with the Oregon project aiming to be up and running by 2030.

As with other early versions of geothermal systems, it is an expensive project to get up and running.

“The economics are somewhat challenging,” Kelso said. “Geothermal is still very expensive today because you’re not getting as much energy out of that well as you would if you were using that well for fossil fuels.”

But Quaes hopes that the economy will improve by targeting higher temperatures between 300C and 500C.

While the high end of that temperature range is ambitious, hotter is the better case.

“It allows you to get 10 times more energy per well than geothermal,” Kelso said.