According to its own website, Hawaii is the most fossil fuel dependent state in the United States. However, its big goal is to become 100% energy dependent by 2045. This is being done with a combination of solar, wind, and smart meters on residential buildings. But now, it's also going to be home to the first and the world's largest fully-closed Ocean Thermal Energy Conversion (OTEC) plant.
According to the Makai website, "Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold ocean water and warm tropical surface waters. OTEC plans to pump large quantities of deep cold seawater and surface seawater to run a power cycle and produce electricity. OTEC is firm power (24/7), a clean energy source, environmentally sustainable and capable of providing massive levels of energy."
Although this project seems like a bit of a white elephant, the cost is $5 million and only produces enough energy to power 120 homes, but the military has invested in this project expecting that this technology can be used to power their ocean side bases. Originally, designed as a proof-of-concept, there are already plans to scale up this technology in Japan and basically any country that is tropical and deep water is an ideal location. Although it may seem like a lot of money, it's worth bearing in mind, that a commercial wind turbine can cost between 1.3 and 2.2 million for an unreliable power source. At least the OTEC is guaranteed around the clock.