23 million square miles of tropical oceans daily absorb solar radiation equal in heat content to about 250 billion barrels of oil. Ocean thermal energy conversion technologies convert this solar...
Capturing Ocean Heat
Ocean thermal energy conversion offers a timely renewable alternative.
operating tests. Testing of an open-cycle OTEC plant at NELHA in 1993 produced 50 kW during a net power-producing experiment. In 1996, Japan’s Saga University entered into an agreement with the National Institute of Ocean Technology of India to collaborate on the design and construction of a 1 MW plant to be located off the coast of Tamil Nadu in India. The facility, built in 2002 with Xenesys Inc., was unsuccessful due to a failure of the deep sea cold water pipe and has since been decommissioned.
Renewed interest in OTEC occurred in the second half of the first decade of the 21st century when fossil-fuel prices began to climb, and concerns were raised about the environmental impacts of continued usage of these carbon-based fuels, as well as energy-related security issues. Further, the necessary component technologies that go into developing a viable OTEC infrastructure has benefitted from complimentary research and development efforts undertaken in the past several decades for other purposes.
As a part of comprehensive energy legislation Congress passed in 2007, the Marine and Hydrokinetic Renewable Energy Research and Development Act was enacted. This law created a DOE program to support renewed research into OTEC (as well as tidal, wave and other marine or hydrokinetic energy technologies), and authorized spending $50 million a year through 2012 for technology R&D, as well as grants to universities to establish marine energy R&D centers. 8 Management of this program is within the DOE office that also oversees wind and hydropower. Congress provided $10 million for “Water Power R&D” in Fiscal Year (FY) 2008 and another $40 million for FY 2009, 9 which enabled the DOE to fund grants under this program. In September 2008, DOE announced the first grants, totaling up to $7.3 million, released under this program, and which included two grants related to OTEC. Up to $.6 million for a possible 2 years was awarded to Lockheed Martin to “validate manufacturing techniques for coldwater pipes critical to OTEC in order to help create a more cost-effective OTEC system,” and another $1.25 million for as many as 5 years to the University of Hawaii to establish the National Renewable Marine Energy Center, which in part will “assist the private sector in moving ocean thermal energy conversion systems beyond proof-of-concept to pre-commercialization, long-term testing.” 10 Furthermore, funding committed to other ocean-energy research may have cross-pollination opportunities with OTEC, particularly as it relates to controlling corrosion, mitigating damage from ocean forces, and developing high-voltage undersea electrical cables. Finally, funding has been made available by Congress for OTEC research in recent Defense Department spending bills. 11
Unfortunately, federal support for renewable R&D has been highly vola-tile, and in the context of the energy market, very low. 12 As UC Berkeley Professor Dan Kammen wrote, “Many R&D programs have exhibited roller-coaster funding cycles, at times doing more harm than good to the sustainable development and deployment of specific technologies.” 13
While President Obama and his administration have indicated their intent to increase federal support for renewable research, as reflected in the significant amount of