Bill Stewart wrote:
Making biodiesel from virgin oil scales well, since you can use
non-food-grade oils, but there's still a substantial ecological effect of converting land from non-farming or food-farming to energy-farming.
That's a common arguement used against biofuels which doesn't hold water. In the first place, whether it's biodiesel or ethanol, you still have the vast majority of the food left after you extract the oil or ethanol -- meal cake or "brewer's grains" (a very high quality protein). http://journeytoforever.org/biofuel_food.html Right at the moment we have farmers (US) being paid *not* to grow, and/or growing at a loss. Corn is now by far the cheapest fuel for home heating. http://www.gov.on.ca/OMAFRA/english/crops/facts/93-023.htm
Waste vegetable oil has a much different scaling ability - until you get most fast-food french-fry leftovers used for fuel oil, it scales up really well, but after that it hits the wall.
Right, but there's a tremendous amount available right now, and an awful lot getting dumped in landfills and illegally down drains. And if you start looking at gasification of waste biomass, there are amazing amounts available at least in western countries. -- Harmon Seaver, MLIS CyberShamanix Work 920-203-9633 Home 920-233-5820 hseaver@cybershamanix.com http://www.cybershamanix.com/resume.html