The idea of tapping the ocean’s different thermal layers to generate electricity was first proposed in 1881 by French physicist Jacques d’Arsonval but didn’t receive much attention until the world oil crises of the 1970s. In 1979, a US government-backed partnership that included Lockheed Martin, lowered a cold water pipe from a barge off Hawaii that was part of an OTEC system generating 50 kilowatts of electricity. Two years later, a Japanese group built a pilot plant off the South Pacific island of Nauru capable of generating 120 kilowatts.
In the first flush of success, the US Department of Energy began planning a 40 megawatt test plant off Hawaii. Then in 1981, the funding for ocean thermal technologies began to dwindle. It dried up altogether in 1995 when the price of oil began to drop, eventually falling below $20 a barrel.
Now rising fuel costs have revived interest in this neglected technology. In September, the Department of Energy awarded its first grant for ocean thermal energy in more than a decade, giving Lockheed Martin $600,000 to develop a new generation of cold water pipes.
Cohen believes this could eventually lead to 500 MW OTEC plants on floating offshore platforms sending electricity to onshore grids via submarine cables, and factory ships “grazing” the open ocean for power.

Plumbing the oceans could bring limitless clean energy – tech – 19 November 2008 – New Scientist






















