The department said Thursday the larger expenditure is for so-called fairway analysis of geothermal energy resources.
Typically used for oil and gas exploration, the data-mapping process is used to assesses geological formations to get a better understanding of the reserve potential.
With vast reserves of undiscovered hydrothermal energy potentially available, the research and development project could spur more investments in new, unexplored areas for geothermal energy, which uses Earth's internal heat to produce electricity, the Energy Department said.
The $2 million will be used to help encourage the use of taller towers used to support wind turbines, the department said.
Most turbines are about 300 feet tall and towers as much as 90 feet taller could exploit stronger and more consistent winds, it said.
U.S. President Barack Obama has encouraged the development of more renewable energy resources as part of his "all-of-the-above" energy policy. He said during his State of the Union address Tuesday the policy is creating a source of economic stimulus and "leading to a cleaner, safer planet."