Martin Hotze wrote:

Matt Whiting wrote:


Maybe this equation has changed with better technology, but I really wonder.


this will change as soon as there is no oil available. it might be 50 or
100 or 200 years, but the day will come.

But the solution will still not be biofuels as you will have no
pretroleum left to make the fertilizers to grow the fuel crops nor run
the tractors to harvest them. And if the energy required to grow the
crops really is more than the yield, then your answer can't be to power
the tractors with biofuel. :-)

The only real source of energy that is for all practical purposes
unlimited, is solar energy or a derivative of it such as the wind. I
suppose you could also put tidal sourced energy into that category as
well as long as the moon keeps spinning around us.

Matt