; or (B) an open loop system, which circulates ground or surface water directly into the building and returns the water to the same aquifer or surface water source. (3) Large-scale application The term large-scale application means an application for space or process heating or cooling for large entities with a name-plate capacity, expected resource, or rating of 10 or more megawatts, such as a large building, commercial district, residential community, or a large municipal, agricultural, or industrial project. (4) Secretary The term Secretary means the Secretary of Energy, acting through the Assistant Secretary for Energy Efficiency and Renewable Energy. (d) Program (1) In general The Secretary shall establish a program of research, development, and demonstration for geothermal heat pumps and the direct use of geothermal energy. (2) Areas The program may include research, development, demonstration, and commercial application of— (A) geothermal ground loop efficiency improvements through more efficient heat transfer fluids; (B) geothermal ground loop efficiency improvements through more efficient thermal grouts for wells and trenches; (C) geothermal ground loop installation cost reduction through— (i) improved drilling methods; (ii) improvements in drilling equipment; (iii) improvements in design methodology and energy analysis procedures; and (iv) improved methods for determination of ground thermal properties and ground temperatures; (D) installing geothermal ground loops near the foundation walls of new construction to take advantage of existing structures; (E) using gray or black wastewater as a method of heat exchange; (F) improving geothermal heat pump system economics through integration of geothermal systems with other building systems, including providing hot and cold water and rejecting or circulating industrial process heat through refrigeration heat rejection and waste heat recovery; (G) advanced geothermal systems using variable pumping rates to increase efficiency