In retrospect, Tesla may have been cleantech&'s Netscape moment. It didn&'t get off to the world&'s greatest start, but like a few other venture-backed IPOs, lately it has been trading at nearly double its opening price.

Meanwhile, a few other cleantech companies have filed S-1s and several more are waiting in the wings, watching to see what the market does. To continue the Netscape analogy, 2011 could even see Elon Musk emerge as the new Jim Clark if one of his other companies SolarCity files, as some in the industry expect.

Nat Goldhaber of the venture firm Claremont Creek Ventures argues that 2011 will be the year of the cleantech IPO, and it&'s not just because of those handful of hot companies are finally ready for primetime and bankers are itching to take them out. Several factors are finally coming together including general improvement in the economy, soaring global demand for energy and a sense that more favorable cleantech regulation is inevitable, at least on a state level.

Goldhaber joined me by Skype to talk about what sectors and companies could lead next year&'s IPO wave and which company in his portfolio has him the most excited. (There&'s also talk of jetpacks and robot butlers&8230')