FIGURE 5-1 Barriers and concerns for OTEC deployment. OTEC plants work with a small temperature difference that necessitates large physical plants with high seawater flow rates. Such large flow rates may cause a decrease in the available temperature resource due to flow disturbance from the plant and may lead to significant environmental impacts.
industrial process in order to generate a significant amount of electricity. The cold-water pipe is one of the largest expenses in an OTEC plant. As a result, the most economical OTEC power plants are likely to be open-ocean designs with short vertical cold-water pipes. However, these designs face the issue of bringing power to shore. The earliest practical OTEC plants are likely to be based on or near tropical islands that have steep topography, which will make it easier to reach deep cold water and transmit power to shore. In the future, OTEC plants could also use the generated energy to produce hydrogen or extract carbon dioxide from seawater in order to produce synthetic fuel using a modified Fischer-Tropsch process in remote ocean locations. A side benefit could be in using pumped-up cold seawater for air conditioning systems, with costs of one-