At the same time, however, islands across the globe depend on diesel, which makes electricity incredibly expensive compared to regions that rely on other fossil fuels such as coal or natural gas. Hawaii, for example, has the highest electricity rates in the United States, about double the price of the next closest state.
Branson's challenge in the Caribbean already has the support of Aruba, British Virgin Islands, St. Lucia and Turks and Caicos. Aruba, for example, already has a wind farm and is planning more.
Other islands are looking at solar, wind, LED lighting for municipal applications, waste-to-energy, and geothermal. For years, Barbados has been toying with the idea of using a special breed of sugar cane for co-generation, but has yet to invest in a large-scale project. Late last year, Puerto Rico mandated energy storage to go with wind and solar projects on the island, which could be a model for other islands if it is successful.
On the 74-acre Necker Island, the microgrid will combine wind, solar, and batteries that can support about 80 percent of the island's energy requirements. On small islands, like Necker, microgrids may seem like a natural solution, but cost remains an issue if they are powered by renewables.