US Code

Public Law 119-73 (01/23/2026)

42 U.S.C. § 17191

Definitions

For purposes of this part:
(1)

Engineered

When referring to enhanced geothermal systems, the term “engineered” means designed to access subsurface heat, including stimulation and nonstimulation technologies to address one or more of the following issues:
(A)
Lack of effective permeability, porosity or open fracture connectivity within the heat reservoir.
(B)
Insufficient contained geofluid in the heat reservoir.
(C)
A low average geothermal gradient which necessitates deeper drilling, or the use of alternative heat sources or heat generation processes.
(2)

Eligible entity

The term “eligible entity” means any of the following entities:
(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.
(G)
A consortium of 2 or more entities described in subparagraphs (A) through (F).
(3)

Enhanced geothermal systems

The term “enhanced geothermal systems” means geothermal reservoir systems that are engineered, as opposed to occurring naturally.

(4)

Geofluid

The term “geofluid” means any fluid used to extract thermal energy from the Earth which is transported to the surface for direct use or electric power generation, except that such term shall not include oil or natural gas.

(5)

Geopressured resources

The term “geopressured resources” mean geothermal deposits found in sedimentary rocks under higher than normal pressure and saturated with gas or methane.

(6)

Geothermal

The term “geothermal” refers to heat energy stored in the Earth’s crust that can be accessed for direct use or electric power generation.

(7)

Hydrothermal

The term “hydrothermal” refers to naturally occurring subsurface reservoirs of hot water or steam.

(8)

Systems approach

The term “systems approach” means an approach to solving problems or designing systems that attempts to optimize the performance of the overall system, rather than a particular component of the system.

Pub. L. 110–140, title VI, § 612121 Stat. 1679Pub. L. 116–260, div. Z, title III, § 3002(a)134 Stat. 2487(, , ; , , .)

Editorial Notes

Amendments

Pub. L. 116–260, § 3002(a)2020—Par. (1). , amended par. (1) generally. Prior to amendment, par. (1) defined the term “engineered”.

Pub. L. 116–260, § 3002(a)(2)Pars. (2) to (8). , (3), added par. (2) and redesignated former pars. (2) to (7) as (3) to (8), respectively.

Statutory Notes and Related Subsidiaries

Effective Date

section 1601 of Pub. L. 110–140section 1824 of Title 2Section effective on the date that is 1 day after , see , set out as a note under , The Congress.

Short Title

section 17001 of this titleThis part known as the “Advanced Geothermal Energy Research and Development Act of 2007”, see Short Title note set out under .