Green tech: Good for the planet and your portfolio

We've all heard about the promise of green technology in regards to carbon emissions, the ozone layer and polar bears up on the ice cap. But, it could also save your portfolio. Recent private investment activity in this sector stands out in a depressed marketplace, suggesting that there is considerable upside potential for early investors, not to mention a future for the sector that will later be available to the public.

Four new clean technology deals were recently announced signaling that early stage private investment trend is gaining steam. Some transactions bring new participants to the table, while others reflect the commitment of repeat investments. Investment in clean technologies is robust -- a rare breed in today's market -- and the amounts are far from trivial. Further, they span all stages, from angel financing through private investment in public equity.