What Al Gore is up to

Planet-saving VC;

We're sitting in the giant conference room at Kleiner Perkins Caufield & Byers, where the partners hold their weekly meetings. After loading his plate with Chinese food from a buffet, Gore is firing detailed questions at the management team of Ausra, a Kleiner-backed company in Palo Alto whose technology uses mirrors the width of a flatbed truck that focus the sun's energy to generate electricity.

Once Gore is satisfied -- sunlight lags north of South Dakota, an Ausra plant can serve 120,000 homes, and yes, smaller turbines will work fine -- he shifts from inquisitor to fixer. He was chatting with California Senator Barbara Boxer "on the way over," he reports, and he isn't optimistic that Congress will extend the tax credits Ausra has been relying on. On the upside, he offers on the spot to organize a summit highlighting the company's solar thermal technology to educate lawmakers and other policymakers on its potential. He also thinks a powwow at General Electric (Charts, Fortune 500) would be beneficial, even though Ausra is a tiny customer.

"I know Immelt well," he says, referring to GE's CEO. "We ought to set up a meeting."

Gore appears utterly comfortable with this drill, but in fact he's engaging in some on-the-job training. The recovering politician, environmental activist, and Nobel laureate is adding another title to his résumé: venture capitalist. After "a conversation that's gone on for a year and a half," according to Gore, he has decided to join his old pal John Doerr as an active, hands-on partner at Kleiner Perkins, Silicon Valley's preeminent venture firm.

The move is more than another Colin Powell moment (the former Secretary of State signed on as a Kleiner "strategic limited partner" two years ago and has hardly been heard from since). Gore is joining the firm as Kleiner makes a risky move beyond information technology and health-care investing into the fast-growing and increasingly competitive arena of "clean technology."