Tesla CEO Elon Musk pledged to send hundreds of energy-storing batteries to Puerto Rico to help the island recover from the devastating hurricane that took all of the island’s 3.4 million residents offline. Although no numbers have been announced yet—it's unclear exactly how many batteries Tesla will send, how much they will cost the country, or when they will be delivered—a tweet from Puerto Rico Governor Ricardo Rossello late Friday night said that a team from the Puerto Rican government was in talks with a team from Tesla to make the project happen.

Great initial conversation with @elonmusk tonight. Teams are now talking; exploring opportunities. Next steps soon to follow. — Ricardo Rossello (@ricardorossello) October 7, 2017

Tesla announced last weekend that a 100MW/129MWh South Australian Powerpack battery installation was halfway complete. That project grew out of a Twitter bet between Australian billionaire Mike Cannon-Brookes and Musk—the Tesla CEO promised that his company could install a battery system in 100 days to help South Australia in the wake of widespread blackouts the summer before. If Tesla missed the 100-day deadline, the system would be free of charge.

Tesla has also built solar-and-battery systems for Ta'u and for Kauai. “The Tesla team has [built solar grids] for many smaller islands around the world, but there is no scalability limit, so it can be done for Puerto Rico too,” Musk said in a tweet. He noted that moving forward would be in the hands of the Puerto Rico government, commercial stakeholders, and the people of Puerto Rico.

The CEO added on Friday night that aid to Puerto Rico, as well as recent low Model 3 production numbers, would also affect semi announcement plans. “Tesla Semi unveil now Nov 16. Diverting resources to fix Model 3 bottlenecks & increase battery production for Puerto Rico & other affected areas." The CEO also said that Tesla was sending staff to train battery installers.

Another, lesser-known vendor of home battery systems—German microgrid company Sonnen—announced last week that it was shipping Sonnen home batteries to Puerto Rico to help set up more microgrids in the area.

In a press statement, Sonnen said it was already sending batteries to the island from its manufacturing center in Atlanta, Georgia. The company is partnering with local renewable energy company Pura Energia to install the systems. “With over 21,000 actual working installations worldwide, Sonnen's energy storage system is uniquely equipped to help provide relief in Puerto Rico, with no delay,” the press statement said. “In fact, since early 2016, Sonnen has had functional energy storage systems installed in Puerto Rico.”

Sonnen said Pura Energia would target emergency relief sites first, offering subsidized solar and battery systems to “emergency medical clinics” that need refrigerators to store medicine, and then move on to connecting other emergency shelters. “Sonnen management is also interested in partnering with a clean water filtration company” to complement the installations at these emergency medical clinics and shelters, the company said.

As of late last week, Puerto Rico's Electric Power Authority had only restored power to nine percent of the island's customers.