Staging Rankine cycles using ammonia for OTEC power production

Recent focus on renewable power production has renewed interest in looking into ocean thermal energy conversion (OTEC) systems. Early studies in OTEC applicability indicate that the island of Hawaii offers a potential market for a nominal 40-MWe system. A 40-MWe system represents a large leap in the current state of OTEC technology. Lockheed Martin Inc. is currently pursuing a more realistic goal of developing a 10-MWe system under U.S. Navy funding (Lockheed 2009). It is essential that the potential risks associated with the first-of-its-kind plant should be minimized for the project's success. Every means for reducing costs must also be pursued without increasing risks. With this in mind, the potential for increasing return on the investment is assessed both in terms of effective use of the seawater resource and of reducing equipment costs.