San Francisco (CNN Business) When Hurricane Maria hit Puerto Rico in 2017, many residents lost power for months -- and some neighborhoods are still struggling to get electricity back up and running.

Puerto Rico had solar panel fields generating power before the hurricane, but much of it was inaccessible when the grid (or the network that delivers electricity to people) went down.

That's one of the biggest challenges with solar energy, which provides an alternative way to power homes and businesses. The technology is still limited, not only because sunlight collection can be inconsistent on cloudy days and unavailable at night, but also because rural or remote areas often lack proper infrastructure.

Some companies are working on solutions to make solar energy technology more resilient and efficient.

Solar panel debris is seen scattered in a solar panel field in the aftermath of Hurricane Maria in Humacao, Puerto Rico on October 2, 2017.

"Solar, in the old sense, is where the system shuts off with the grid," Yotta Solar co-founder Omeed Badkoobeh told CNN Business. "The future of solar is where systems are independent of the grid."

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