Announcements of potentially disruptive clean-tech breakthroughs are a weekly occurrence, and though most will come to naught, some will have a huge impact. This is both fun to watch and exhilarating, since each announcement brings a world of sustainable abundance that much closer. But for investors, rapid change means heightened risk to incumbent green technologies. If they work, it may be at the expense of that high-priced stock you just bought.

Eternal Vigilance

That so many of the breakthroughs (listed to the right) which, remember, are just a fraction seem to have such dramatic potential means that no clean-tech investment is entirely safe. Let MIT come up with solar power for $0.02 per kWh or Synthetic Genomics design a bug that produces biofuel for $0.50 a gallon, and it's game over for yesterday's favorites. So the final piece of a good clean tech investment program is, like Mad-Eye Moody says, eternal vigilance. Track the developments in the fields where your money resides and assess their potential as both threats to your existing stocks and as future investments themselves.