Cleantech companies applying new technologies to old problems faced by the world’s poor are attracting funds. But the money’s coming from Silicon Valley venture funds, not NGOs.

Venture funds Walden International and New Enterprise Associates (NEA) are looking into funding India-based Novatium, developer of a $100 personal computer.

Khosla Ventures invested an undisclosed amount in Stanford University-incubated Cosmos Ignite Innovations in 2006. The company’s $50 solar-powered lights have sold so well in India that the company has attracted additional potential investors including Omidyar, eBay (Nasdaq: EBAY) founder Pierre Omidyar’s fund, and London-based 3i Group both of which were in talks with the company in July 2007. Other funds, including Sequoia Capital, are investing in “bottom of the pyramid” (BOP) startups as well.

Rob Day, who manages @Ventures’ cleantech fund, says interest in BOP has increased for several reasons: The cleantech boom has brought global issues to the attention of investors, people have gotten a better understanding that those at the bottom of the pyramid do have some buying power, and microcredit start-ups have demonstrated that, with the appropriate infrastructure and products, a lot of small opportunities can scale into big opportunities.

The needs of BOP include everything from clean water and electricity to computers, but Day says some of the best plays are those that combine something for both ends of the pyramid. “A lot of technology companies are aiming at dual markets, both at deep-pocketed markets in the United States and Europe, and with slightly different twists on the technology for the bottom of the pyramid,” he says.