Iceland is a leader in investigating superhot rock geothermal energy with its Iceland Deep Drilling Project. A test there suggests one well could produce 36 megawatts of energy, which is five to ten times more than the typical three to five megawatts of energy a conventional geothermal well could generate.
Iceland is well suited to study geothermal energy because of it's located where the American and Eurasian crustal plates are pulling apart from each other.
"We are replenished with constant supplies of magma energy to feed our geothermal systems," Guðmundur Ó. Friðleifsson, who served as a coordinator and principal investigator in the IDDP effort for over 20 years, told CNBC. "Magma energy is also at relatively shallow depths and relatively easily accessed, and Icelanders by nature are explorers of Celtic and Norse origin who love to sail into or out to the unknown," Friðleifsson said.
Beyond Iceland, Italy, Japan, New Zealand and the United States are leaders in superhot rock geothermal, according to Friðleifsson. Other areas on the edges of tectonic plates, including Central America, Indonesia, Kenya and the Philippines, also have some development.
For superhot rock geothermal energy to be commercialized and deployed broadly will require new technology, including rapid ultra-deep drilling methods, heat-resistant well materials and tools, and ways to develop deep-heat reservoirs in hot dry rock.
These are not insignificant, but they are "engineering challenges, not needed scientific breakthroughs," the CATF report says.
For example, drilling into hard crystalline rock takes a long time with current rotation drill techniques and the drill bits have to be replaced frequently. One potential solution is using energy instead of a mechanical drill.
Quaise Energy is develoing such a drill, building on research from Paul Woskov at MIT. The Quaise drill is being tested at Oak Ridge National Laboratory, according to CATF.
"The solution to drilling is to replace the mechanical grinding process with a pure energy-matter interaction. Sufficient energy intensity will always melt-vaporize rock without need for physical tools," Woskov told CNBC.
"Directed energy drilling has been considered since the laser was invented in the 1960s, but so far unsuccessfully because the infrared wavelengths are scattered in a drilling environment, the laser sources are of too low average power, and lasers sources are not efficient. We now have gyrotron sources since the 1990s that operate at millimeter-wavelengths that are more robust in a drilling environment, more powerful, and more efficient."