1. Introduction
Vast and powerful, the ocean probably stores enough energy in the form of heat, currents, waves, and tides to meet total worldwide demand for power many times over [1]. Yet the challenges facing development of ocean energy technology have been daunting, and to date, ocean energy comprises only a miniscule proportion of worldwide energy supply. Now, however, widespread concern over global climate change and other environmental impacts of worldwide reliance on fossil fuels has increased interest in renewable energy. As global commitment to renewables increases in the future, more attention is likely to become focused on the immense stores of energy in the ocean.
Increased research and development of renewable energy from the ocean may be necessary for a broad, comprehensive, and responsible energy plan. While renewable energy from the ocean would most likely improve the environment by replacing fossil fuel plants and reducing carbon emissions, we must ask the question “and then what?”. It will be critically important to ensure that the development of new ocean energy technologies does not harm the marine environment, which is already subject to multiple threats such as overfishing, pollution, habitat loss, and climate change. This paper will present and compare major potential sources of renewable energy from the ocean with a view toward developing responsible development guidelines for protecting the marine environment.