One of Hawaii’s islands may soon be powered by solar energy, at least during the night.

In the biggest project since it acquired the solar cell giant SolarCity, the Tesla company will build a 13-megawatt solar farm on the island of Kauai, covering more than 44 acres (18 hectares). The solar cells will charge a 53-megawatt hour battery station able to provide most of the island’s power at night.

The batteries, called Powerpacks, will be built by Tesla’s new Gigafactory, according to Voice of America.

Right now, Kauai residents are paying very high prices for energy, so the plan is to gradually transition to renewable sources, including wind and biomass.

Kauai plans to generate 70 percent of its power from renewable sources by 2030 and to completely wean itself from fossil-generated electricity by 2045.

Tesla says that once it’s in full production, the Kauai solar energy plant will lower the fossil fuel burn by over 6,000 metric tons a year.