Ken LaRoe was building his third bank when he finally learned to keep it. Climate First Bank, founded in St. Petersburg, Florida in 2021, has already become the nation's fastest-growing new bank—and it's not chasing crypto or exotic investment schemes. It finances solar arrays, battery storage systems, and renewable energy projects that actually reduce carbon emissions.

The bank's meteoric rise matters because it proves something investors and regulators have long doubted: lending for environmental sustainability isn't a niche cause or a charitable write-off. It's a scaled, profitable business model that's hungry to grow. With nearly $1.8 billion in assets after just five years, Climate First Bank nearly doubled its size during 2025 alone—a growth trajectory that puts it well ahead of schedule to reach its ambitious goal of $10 billion in assets within its first decade.

LaRoe's path to this moment was anything but straightforward. After chartering Florida Choice Bank in 1999 and selling it to a regional bank by 2006, he set out to retire with an RV tour. Reading about Patagonia founder Yvon Chouinard's philosophy that business should mean more than shareholder profit, LaRoe pivoted. He launched First Green Bank in 2009, rallying his network of investors behind an explicit mission to support environmental sustainability. By 2018, First Green Bank had grown to $800 million in assets. But when its shareholders sold it to a larger Florida bank, LaRoe discovered that mergers rarely preserve founding missions. He left to start fresh.

This time, Climate First Bank was built differently—designed to stay independent and lean into relationships rather than replace them with technology. The strategy has proven decisive. While the bank finances everything from residential rooftop solar to utility-scale battery storage, its growth engine is fundamentally human. The founder tapped his existing network for startup capital. He hired lenders with years of experience in Central Florida's solar sector. Most importantly, he and his team invested time understanding how solar developers and renewable energy companies actually work—the messiness and specifics that algorithms miss.

That attention creates snowball effects. One good experience with the bank spreads through the solar industry by word of mouth. Business cards and referrals multiply. Hana Freymiller, the bank's Director of Project Finance, candidly captured the pressure: "I wish there were five of me that could be doing this work. There's just a tremendous need and also a tremendous opportunity right now in this country to do these types of projects."

Much of Climate First's early success clusters in "blue cities in red states," according to Chief Sustainability Officer Chris Castro—urban centers with green banks and public institutions committed to renewable energy. These regions provided a natural runway for the bank's mission-driven lending model.

Now, facing demand that exceeds its own institutional capacity, Climate First Bank is seeking partners to scale beyond what a single lender can reach. The bank isn't looking to be acquired and absorbed. It's looking to multiply. After two lessons in what happens when green banks merge into larger institutions, LaRoe and his team are building something designed to last—and to grow while keeping its purpose intact.