Clean tech investment differs from traditional venture capital (VC) sectors by virtue of need to  lengthen the time horizon of involvement in investments–in both directions, that is, more  investment and involvement in firms at an earlier stage of technology development and with firms  in a later stage of technology commercialization. Consequently, clean tech VC investing requires  changes to the traditional VC approach.  In this paper, we provide some evidence that suggests  that these changes are occurring, that VCs indeed may be in the process of adapting to the  requirements of clean tech investing. This paper reviews both the potential and limitations of  venture capital as a source of funding for clean energy. It tries to paint an accurate picture of the  realities of VC funding of clean energy as it has evolved during the last decade. In this paper, we  provide preliminary evidence that suggests that the more clean energy becomes a part of the VC  world the more venture capitalists are adjusting their operating procedures to accommodate this  category of investment. The evidence suggests that a number of adjustments are taking place.  First, because of a fixed pool of resources, VCs are investing larger amounts of their money for  longer periods of time. Second, they increasingly have been avoiding high risk clean energy  production, distribution, and installation manufacturing and production companies and funding the  back and front ends of the solar energy supply chain and startups that focus on the intersection  between energy and information technologies areas.  Third, besides making bigger bets, stretching  out their timetables, and avoiding high risk and capital intensive companies, they have been  experimenting more by investing in a greater number of firms in risky technologies whose  commercialization is less imminent.  If the VC role in clean energy is to be more transformative  we believe it is because that these trends will gain momentum, but how deep these adjustments are  and whether they will grow in the future is not certain.