An energy island is a floating structure which is designed to harness energy from renewable sources and transmit that energy back to land. There are a number of ways in which an energy island could work, with a number of experimental proposals being brought to investors in the early 2000s, when the concept first began to garner serious attention. There are a number of potential advantages to using an energy island as a power source, not least of which is that it decreases dependence on non-renewable sources of energy like coal and petroleum.
Essentially, an energy island is designed like an oil rig, except that instead of collecting petroleum from the ocean, it can gather energy from wind, waves, and the sun. Some proposals have also included a potential for ocean thermal energy conversion (OTEC), a form of alternative energy which harnesses the temperature differential between the warm upper layers of the ocean and the cold depths to generate energy. A mixture of energy generation techniques could be used to make an energy island as useful as possible.
There are several challenges to the energy island concept. The first involves efficient storage and/or transmission of the energy. Ideally, energy should be used close to its source, to maximize efficiency, and energy islands would require some form of technology to move the harvested energy to a usable location. Batteries are a potential way to store and move the energy gathered on an energy island, but a method for developing high capacity, high efficiency batteries must be developed for energy islands to be productive.
Beyond the obvious reduction of reliance on non-renewable fuels, energy islands have some other advantages. In densely inhabited areas, an energy island could be used to collect energy without taking up valuable real estate which could be used for farming or housing. In regions where people complain about energy generation stations as eyesores, offshore energy islands could collect energy without offending aesthetic sensibilities.
In addition to housing power generation facilities, an energy island could also potentially be used to make a living space. Housing for people who work on the maintenance of the generation system could be very useful, but offshore communities of people living on such islands could also become appealing to some individuals. Energy islands can also be used as staging points for marine research, opening up more opportunities to scientists who work on various projects which pertain to the ocean.