The world will see a significant increase in the use of geothermal as an energy source between now and 2020.

That's according to a report released this week by Pike Research.

The research analyst constructed several scenarios based on an estimated 10.7 gigawatts of geothermal capacity in existence throughout the world in 2010.

That 10.7 gigawatts equates to about 67 terawatt-hours (TWh) of electricity, with the U.S., which currently possesses 3.1 gigawatts of installed geothermal systems, as the world's leading user.

In fact, 88 percent of the world's geothermal energy systems currently in operation are used in only eight countries, according to the report.

Peter Asmus, the senior analyst on the report, emphasized that geothermal is currently one of the world's least-tapped opportunities for alternative energy.

"Worldwide potential for geothermal energy is immense, but geothermal remains an underutilized resource and represents only a small fraction of the global renewable energy portfolio. Improved access to resource data, more efficient drilling processes, increased understanding about the industry's potential, and improving access to financing are driving expanding interest in the sector," he said in a statement.

In the report's high-growth forecast, geothermal capacity increases 134 percent to 25.1 gigawatts. In the report's most conservative forecast, Pike estimated that world geothermal capacity will grow to 14.3 gigawatts by 2020.

The statistics are in line with scientists who've said that geothermal is an untapped resource that could potentially supply 4 percent of the world's energy needs. The Geothermal Energy Association has calculated that the U.S. has the potential to supply 7 million people with energy on geothermal alone if currently planned projects move forward, which would increase capacity from 3.1 gigawatts to 7 gigawatts.