Even if the sun doesn't shine for three days, this island can still maintain electricity.
Ta’u, an island in American Samoa, used to run off crude oil but is now entirely powered by a solar array and battery packs. This was made possible thanks to green tech business Tesla/Solar City (which recently merged), as well as the American Samoa Economic Development Authority, the U.S. Environmental Protection Agency and the Department of Interior, all of which helped fund the $8 million venture.
According to Radio New Zealand, the island previously used as much as 300 gallons of fuel a day (that’s 109,500 a year!) to power itself. At times, the island’s 600 residents would wait months for fuel shipments. In effect, electricity had to be rationed and power outages were common. Now, however, the island can go three days without sun and still maintain electricity. When the sun does shine, the microgrid can recharge to full capacity in only seven hours.