42 U.S.C. § 17191 — Definitions

For this part: (1) Engineered: When talking about enhanced geothermal systems, "engineered" means designed to reach underground heat — using stimulation or non-stimulation methods — to fix one or more problems: (A) not enough effective permeability, porosity, or connected fractures in the heat reservoir; (B) not enough contained geofluid in the reservoir; or (C) too low an average geothermal gradient, which forces deeper drilling or alternative heat sources or generation methods. (2) Eligible entity: means any of: (A) an institution of higher education; (B) a National Laboratory; (C) a Federal research agency; (D) a State research agency; (E) a nonprofit research organization; (F) an industrial entity; or (G) a consortium of two or more of these. (3) Enhanced geothermal systems: means geothermal reservoir systems that are engineered, rather than occurring naturally. (4) Geofluid: means any fluid used to pull thermal energy from the Earth and bring it to the surface for direct use or electricity generation — but not oil or natural gas. (5) Geopressured resources: means geothermal deposits found in sedimentary rock, under higher-than-normal pressure and saturated with gas or methane. (6) Geothermal: refers to heat energy stored in the Earth's crust that can be used directly or to generate electricity. (7) Hydrothermal: refers to naturally occurring underground reservoirs of hot water or steam. (8) Systems approach: means an approach to solving problems or designing systems that tries to optimize the whole system's performance, not just one part of it.