For purposes of this part, the term “marine and hydrokinetic renewable energy” means electrical energy from—

(1) waves, tides, and currents in oceans, estuaries, and tidal areas;

(2) free flowing water in rivers, lakes, and streams;

(3) free flowing water in man-made channels; and

(4) differentials in ocean temperature (ocean thermal energy conversion).

(Pub. L. 110–140, title VI, § 632, Dec. 19, 2007, 121 Stat. 1686.)