dkitI agree with most of what you say although possibly thin...

dkit

I agree with most of what you say although possibly thin film photovoltaics could be placed on the list of possibilities. These devices have much less ultrarefined silicon than cells cut from wafers.

Bioethanol is certainly marginal in terms of its energy budget; particularly if it is sourced from grain rather than sugarcane. Biodiesel may be more energy efficient than bioethanol but I came very close to losing money when ABJ slid off the rollercoaster.

Geothermal certainly has potential and I have modest holdings of Geodynamics options atm. However, I'm inclined to think GDY is fully priced right now.