Diesel generators used to slurp 300 gallons of fuel per day so that residents and business owners on a remote island in American Samoa could turn on their lights.

But within a year, Ta’ū Island switched to using solar and battery power: its new microgrid system electrifies the island with nearly 100 percent renewable energy.

Diesel was expensive and dirty, and had to be shipped to the island by boat. “I recall a time they weren’t able to get the boat out here for two months,” said Keith Ahsoon, a resident of Ta’ū. He said rationing and candlelight were a fact of life. “It’s hard to live not knowing what’s going to happen,” he said.

Today, Ahsoon has reliable electricity. Here’s how the new system works:

  • 5,328 solar panels produce power for Ta’ū’s 600 residents.
  • 60 rechargeable “Powerpack” batteries made by the U.S. company Tesla store excess solar energy for use at night or on cloudy days.
  • The system stores power for up to three days and can recharge in seven hours of sun.

Switching to solar proved cheaper than depending on unreliable diesel with fluctuating prices. The U.S. Environmental Protection Agency and the Department of the Interior helped provide funding.

Ta’ū isn’t alone. Around the world, many island communities that depend on fossil fuel generators are poised to follow its lead. SolarCity, which Tesla recently purchased, figures that declining costs make solar and energy storage cost less than diesel almost anywhere.

“This is part of making history,” Ahsoon said, adding that island residents see the effects of global warming firsthand. “This project will help lessen the carbon footprint of the world,” he said.