; (B) free flowing water in rivers, lakes, streams, and man-made channels; (C) differentials in salinity and pressure gradients; and (D) differentials in water temperature, including ocean thermal energy conversion. (4) National laboratory The term National Laboratory has the meaning given such term in section 2(3) of the Energy Policy Act of 2005 ( 42 U.S.C. 15801(3) ). (5) Microgrid The term microgrid has the meaning given such term in section 641 of the Energy Independence and Security Act of 2007 ( 42 U.S.C. 17231 ). 633. Marine energy research, development, and demonstration (a) In general The Secretary, in consultation with the Department of Defense, Secretary of Commerce (acting through the Under Secretary of Commerce for Oceans and Atmosphere), the Secretary of the Interior, and other relevant Federal agencies, shall conduct a program of research, development, demonstration, and commercial application of marine energy technology, including activities to— (1) assist technology development to improve the components, processes, and systems used for power generation from marine energy resources at a variety of scales; (2) establish and expand critical testing infrastructure and facilities necessary to— (A) demonstrate and prove marine energy devices at a range of scales in a manner that is cost-effective and efficient; and (B) accelerate the technological readiness and commercial application of such devices; (3) address marine energy resource variability issues, including through the application of energy storage technologies; (4) advance efficient and reliable integration of marine energy with the electric grid, which may include smart building systems; (5) identify and study critical short- and long-term needs to maintaining a sustainable marine energy supply chain based in the United States; (6) increase the reliability, security, and resilience of marine energy technologies