The investment will go toward so-called Enhanced Geothermal Systems. Whereas conventional geothermal technology relies on finding naturally occurring pockets of steam and hot water in the ground, EGS works by injecting regular unheated water into “hot basement rock” deep below the planet’s surface. This heated water is the forced through and rises to the surface where it can be mined for all its hot water glory (remember: heat is an untapped source of stored energy!)
The US Department of Energy likes the potential of EGS:
More than 100,000 MWe of economically viable capacity may be available in the continental United States, representing a 40-fold increase over present geothermal power generating capacity. This potential is about 10% of the overall U.S. electric capacity today, and represents a domestic energy source that is clean, reliable, and proven.