Jehu Garcia didn’t expect to be known for working with Lithium-ion batteries. The California-based YouTuber previously started a photography accessories company, and originally thought his life was more about cameras and making videos. “I didn’t want to be known as the battery guy,” Garcia told me on a recent phone call.

But then, in 2015, Elon Musk unveiled the Tesla Powerwall. The suitcase-sized battery lets homeowners store electricity, either from the grid or solar panels. The device represented an impressive step forward in alternative energy technology, but it started at $3,000 and could only store 10 KWh of electricity, or about a third the average American household consumes in a day.

Inspired by Tesla, battery hobbyists started building their own DIY powerwalls using recycled laptop batteries and hooking them up to solar panels for a fraction of the cost. They turned to YouTube, Facebook, and dedicated online forums to swap techniques and find out where to buy supplies. Garcia, via his instructional YouTube videos, quickly became one of the most respected and influential DIY powerwall enthusiasts on the internet.

Two years before the Powerwall was released, Garcia converted a vintage Volkswagen bus to run on an electric battery instead of gasoline. He was also already a fan of Tesla, and knew a little about Lithium-ion batteries, which are used in everything from cellphones and laptops to Powerwalls. So he started making videos teaching others how to build their own alternative and recycled energy source.

Garcia quickly became popular, and his videos started garnering tens of thousands of views. He began to not only teach people how to build batteries, but also to secure lots of 18650 cells—the kind needed to make DIY powerwalls—to distribute to his audience.

Garcia ultimately isn’t just another YouTuber in it for the views, he has become a community leader dedicated to changing how we all think about energy. He aims to prove to the world that you don’t need a corporation or nonprofit to help you go off the grid, you can do it yourself.

In October, I visited Garcia at his modest home in the sleepy suburb of Rancho Cucamonga, about an hour outside of Los Angeles. Next to his garage, he has built himself a makeshift studio, where he often works with batteries and films his YouTube videos.

Garcia doesn’t have any formal training, and hasn’t ever taken a professional engineering class. He was brought over the border from Mexico as a child, and never attended college. But he uses his unusual background to his advantage, because he’s far easier to relate to than a tech executive or professional engineer. If Garcia can build a DIY powerwall, you can too.

With over 140,000 YouTube subscribers, Garcia is dedicated to making videos full time, and has big plans for the future. When I first wrote about DIY powerwall builders in August, he told me he was planning to one day build one of the biggest privately owned sources of power in the US. The giant battery system will be able to store 1 megawatt of power, or 1000 kWh, Garcia says. “We’re going to power a recycling facility,” he told me at the time.

Last month, Garcia traveled to a place that could perhaps use alternative sources of energy more than anywhere else: Puerto Rico. In September, the US territory was devastated by Hurricane Maria, a category 5 storm that destroyed crucial infrastructure on the island and killed hundreds of people.

Garcia says he raised between $30,000 and $40,000 via donations to bring small powerwalls and solar panels to over 30 families so far without power on the island. The majority of Puerto Rico’s 3.4 million residents are believed to still be without electricity, nearly three months after the storm hit shore.

Where many people might see in Puerto Rico only a humanitarian crisis, Garcia sees a bright future powered by alternative energy. “I think it’s an opportunity much more than a tragedy,” he said, referring to the island’s power crisis.

He thinks if people witness solar panels and recycled batteries working on the island, they’ll be more willing to invest in the technology elsewhere. “I think if people see it, if industry sees it, it’s going to be the first part of the US where the future starts.”