Marine and Hydrokinetic Renewable Energy Promotion Act of 2010

Marine and Hydrokinetic Renewable Energy Promotion Act of 2010 - Amends the Energy Independence and Security Act of 2007 to revise the program of marine and hydrokinetic renewable energy technology research, development, demonstration, and commercial application, including by requiring the program to include specified activities, including: (1) determining the potential availability, extractability, and cost-effectiveness of marine and hydrokinetic renewable energy generation in the United States; (2) designing and developing evaluation and performance standards domestically and with international partners; and (3) improving interagency collaboration to address challenges associated with the development of such technologies. Requires such program to be separate from the Department of Energy's (DOE) Wind and Hydropower Program.

Requires the Secretary of Energy to establish a competitive marine and hydrokinetic renewable energy technology demonstration grant program to: (1) verify the performance, reliability, maintainability, environmental impact, and cost of technology components, devices, and system designs in an operating environment; and (2) facilitate the commercial application of technology components, devices, and systems at a variety of scales.

Requires the Secretary to establish a competitive research, development, and demonstration grant program to identify and assess ways to avoid and minimize environmental impacts potentially arising from marine and hydrokinetic renewable energy technologies, devices, and systems.

Requires the Secretary to award competitive grants to support modifying or constructing three or more geographically dispersed marine and hydrokinetic renewable energy technology research, development, and demonstration test facilities for the demonstration of multiple technologies in actual operating environments.

Authorizes National Marine Renewable Energy Research, Development, and Demonstration Centers to serve as technology test facilities.