The ocean harbours several possible energy sources which we might be able to harness for our massive and growing need. Sources such as oil and gas deposits beneath the sea floor are non-renewable, and though there are a lot of them which can be capitalised upon, they will eventually run out, and of course, they produce pollution when converted to electricity. Many oil platforms have been built at sea to pump out the black gold, which is plentiful-when found. Geologists and other scientists, with the help of equipment and physical labour, have to investigate the ocean floor to find potential oil sources, and the cost of building, maintaining and running an oil platform is very high.

Other promising sources are the renewable ones. One important and well-known example is the harnessing of waves to generate electricity; there are various proposals of methods to accomplish this, and heavy experimentation has taken place to determine the feasibility of certain promising designs and how efficient they are. Many organisations and countries are designing or developing wave-energy devices. Another possibility is the use of ocean thermal heat or heat from undersea vents; the latter refers to vents in the sea floor through which heat escapes, together with various chemicals like sulphur. It is more difficult to experiment with vents due to their location, but countries like India have investigated or are investigating methods to harness ocean thermal energy.