Marine and Hydrokinetic Renewable Energy Act of 2014 - Title I: Marine and Hydrokinetic Renewable Energy Technologies - (Sec. 101) Amends the Energy Independence and Security Act of 2007 to redefine "marine and hydrokinetic renewable energy" to include all forms of energy (currently just 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).

(Sec. 102) Requires Department of Energy (DOE) to consult with the Federal Energy Regulatory Commission (FERC) in carrying out the program of research, development, demonstration, and commercial application to accelerate the introduction of marine and hydrokinetic renewable energy production. Requires DOE to prioritize fostering accelerated research, development, and commercialization of technology.

Expands such program, including by: (1) incorporating technology development assistance to improve the components, processes, and systems used for power generation from marine and hydrokinetic renewable energy resources; (2) establishing critical testing infrastructure; (3) increasing the reliability and survivability of such technologies; and (4) supporting in-water technology development with international partners.

(Sec. 103) Declares that the purposes of a National Marine Renewable Energy Research, Development, and Demonstration Center include:

• advance research, development, demonstration, and commercial application of marine and hydrokinetic renewable energy technologies;
• support of in-water testing and demonstration of such technologies; and
• service as an information clearinghouse on best practices for the marine and hydrokinetic renewable energy industry.

(Sec. 104) Extends the authorization of funding for the program through FY2018.

Title II: National Marine Renewable Energy Research, Development, and Demonstration Centers - (Sec. 201) Amends the Federal Power Act to authorize FERC to issue a pilot license to construct, operate, and maintain a hydrokinetic pilot project that meets specified criteria.

Marine and Hydrokinetic Renewable Energy Act of 2013 - Amends the Energy Independence and Security Act of 2007 to redefine "marine and hydrokinetic renewable energy" as energy (currently 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).

Requires the Secretary of Energy (DOE), in addition to current consulting requirements, to consult with the Federal Energy Regulatory Commission (FERC) in carrying out the program of research, development, demonstration, and commercial application to expand marine and hydrokinetic renewable energy production.

Expands such program, including by: (1) adding as a purpose the support of in-water testing and demonstration of marine and hydrokinetic renewable energy technologies; (2) incorporating technology development assistance to improve the components, processes, and systems used for power generation from such resources; (3) establishing critical testing infrastructure; (4) increasing the reliability and survivability of such technologies; and (5) supporting in-water technology development with international partners.

Extends the authorization of funding for such program through FY2017.

Amends the Federal Power Act to authorize FERC to issue a pilot license: (1) to construct, operate, and maintain a hydrokinetic pilot project that meets the criteria listed in this Act; and (2) for such a project located in the ocean if the project covers a surface area of not more than one square nautical mile. Authorizes FERC to grant a pilot license for a project that covers a larger surface area for good cause.