You’ve probably heard of Kiva , the peer-to-peer microfinance website. Founded in 2005, Kiva has earned a reputation as an innovative nonprofit: It has enabled loans to be made to about 573,000 low-income entrepreneurs worth more than $210 million in 60 countries. More than 570,000 people, mostly Americans, have done the lending, and the repayment rate is more than 98% . This would be reason enough to cheer.

Not content with the status quo, though, Kiva lately has pushed into new arenas. Last fall, Kiva added “student microloans” to its range of offerings. Last month, Kiva, added a category called “green loans,” permitting businesses and individuals in poor countries to borrow as little as $25 to make their homes or workplaces more energy efficient, to recycle more or to convert to clean energy sources.

Last week, I talked via Skype with Premal Shah, the 35-year-old president of Kiva about the new initiative. He’s smart and engaging, easy to talk with, and thoughtful about economics, his undergrad major at Stanford. He told me that Kiva, to magnify its impact, he explained, wants to take advantage of the fact that its  lenders are for the most part willing to take risks. People aren’t putting their kids college funds or retirement savings at risk here. So Kiva has the freedom and the opportunity to test new ideas in microcredit.

“The Internet community can come in, take risks, try something that’s unproven,” Premal told me. So Kiva should be constantly exploring the “risk and cost frontiers of microfinance,” pushing the envelope and then hoping that more risk-averse providers of capital, like conventional banks, will follow.  

Premal, who was born in India and moved to Minnesota as an infant,  told me that he got interested in microfinance during his sophomore year...