Self-sufficiency isn't easy on small Pacific islands, but the distant island of Ta'u in American Samoa can now supply nearly all of its inhabitants' power needs using renewable energy.

The island now generates and stores nearly 100 percent of its electricity using a large solar panel array, microgrid and batteries installed by SolarCity and Tesla.

"It's always sunny out here, and harvesting that energy from the sun will make me sleep a lot more comfortably at night, just knowing I'll be able to serve my customers," Keith Ahsoon, a local resident whose family owns and operates a local grocery, was quoted as saying in a SolarCity blog post.

The solar-powered microgrid is managed by the American Samoa Power Authority. As much as 6 megawatt hours of extra solar energy can be stored in 60 Tesla Powerpacks and used at night.

In addition to being cleaner, solar energy is significantly cheaper for islands like Ta'u, which have traditionally relied on imported diesel for their power needs. Shipping in diesel to an island 4,000 miles from the U.S. West Coast is expensive and unreliable.

The new microgrid will replace 109,500 gallons of diesel per year on Ta'u.

For small islands like Ta'u, the consequences of man-made climate change is more immediate, making a switch to sustainable energy more imperative.

"This is part of making history," Ahsoon said. "This project will help lessen the carbon footprint of the world. Living on an island, you experience global warming firsthand. Beach erosions and other noticeable changes are a part of life here. It's a serious problem, and this project will hopefully set a good example for everyone else to follow."

Tesla's aquisition of SolarCity officially closed Monday. The merger comes just weeks after Tesla and SpaceX CEO Elon Musk unveiled SolarCity's new solar-cell roof tiles.