<![CDATA[Grist - Comment Feed for What’s the most energy-efficient crop source for ethanol?]]> Grist Comment Feed en Comment #1 by greenstork http://www.grist.org/article/biofuel-some-numbers/ Tue, 07 Feb 2006 05:30:58 -0800 http://www.grist.org/article/biofuel-some-numbers/1 Soy biodiesel not a long-term solution either

For the same reasons you cite corn ethanol as a boondoggle, soybean based biodiesel is as well.  Now, I drive a car that runs on soy biodiesel and it isn't really a problem with biodiesel making up less than 1% of the diesel fuel market. But if the growth trend continues for both ethanol and biodiesel, switchgrass and algae will be the only real economic and environmentally sustainable solutions.  

As a supplement to your article, algal biodiesel isn't commercially available but also shows promise of providing from 10-15K gallons per acre.  A couple pilot projects are underway:

Toronto Star: Algae farms make case for Kyoto
Worldchanging.com: Turning Emissions Into Fuel With Algae
USA Today: Algae - like a breath mint for smokestacks

]]> Soy biodiesel not a long-term solution either

For the same reasons you cite corn ethanol as a boondoggle, soybean based biodiesel is as well.  Now, I drive a car that runs on soy biodiesel and it isn't really a problem with biodiesel making up less than 1% of the diesel fuel market. But if the growth trend continues for both ethanol and biodiesel, switchgrass and algae will be the only real economic and environmentally sustainable solutions.  

As a supplement to your article, algal biodiesel isn't commercially available but also shows promise of providing from 10-15K gallons per acre.  A couple pilot projects are underway:

Toronto Star: Algae farms make case for Kyoto
Worldchanging.com: Turning Emissions Into Fuel With Algae
USA Today: Algae - like a breath mint for smokestacks

]]> Comment #2 by tlr http://www.grist.org/article/biofuel-some-numbers/ Wed, 08 Feb 2006 11:49:41 -0800 http://www.grist.org/article/biofuel-some-numbers/2 HEMP

What is the yield per acre of hemp, and why is it not incluced in this study?

]]> HEMP

What is the yield per acre of hemp, and why is it not incluced in this study?

]]> Comment #3 by ecacofonix http://www.grist.org/article/biofuel-some-numbers/ Tue, 09 May 2006 03:42:15 -0700 http://www.grist.org/article/biofuel-some-numbers/3 The Pecking Order

Guess the feedstock pecking order for biodiesel & ethanol are as follows:

Biodiesel, the best feedstock appear to be algae (assuming the damn process works that is), jatropja and allied waste crops, palm oil, coconut, rapeseed, and all the rest...soy is simply politically sponsored feedstock (guess America is big in corn)

For ethanol, I think sugarcane is probably the best feedstock, and corn possibly the worst

Just some thoughts

If you folks have time, see also The Biodiesel WWW Encyclopedia for some more info on all these

Narsi, BPO

]]> The Pecking Order

Guess the feedstock pecking order for biodiesel & ethanol are as follows:

Biodiesel, the best feedstock appear to be algae (assuming the damn process works that is), jatropja and allied waste crops, palm oil, coconut, rapeseed, and all the rest...soy is simply politically sponsored feedstock (guess America is big in corn)

For ethanol, I think sugarcane is probably the best feedstock, and corn possibly the worst

Just some thoughts

If you folks have time, see also The Biodiesel WWW Encyclopedia for some more info on all these

Narsi, BPO

]]> Comment #4 by niels W http://www.grist.org/article/biofuel-some-numbers/ Thu, 24 Apr 2008 21:56:12 -0700 http://www.grist.org/article/biofuel-some-numbers/4 Solar Power with electric vehicles is way better

If we cover an acre roof top with solar electric panels here in cloudy Wisconsin it will generate 300,000 kWh per year.  Put that directly into an electric vehicle that gets 3 miles per kWh... and it will go 900,000 miles.

No land is needed, no water, no tilling, no soil loss, no farmer, no biorefinery, no transporation.. and the car's battery is the energy storage device.

We are barking up the wrong tree!

Niels

]]> Solar Power with electric vehicles is way better

If we cover an acre roof top with solar electric panels here in cloudy Wisconsin it will generate 300,000 kWh per year.  Put that directly into an electric vehicle that gets 3 miles per kWh... and it will go 900,000 miles.

No land is needed, no water, no tilling, no soil loss, no farmer, no biorefinery, no transporation.. and the car's battery is the energy storage device.

We are barking up the wrong tree!

Niels

]]> Comment #5 by Ron Steenblik http://www.grist.org/article/biofuel-some-numbers/ Thu, 24 Apr 2008 22:36:24 -0700 http://www.grist.org/article/biofuel-some-numbers/5 David

Um, these numbers say nothing about relative production costs. (And Journey to Forever has a longer list of oilseed yields.)

One of the reasons (besides subsidies) that soy biodiesel exists is that the oil was initially a by-product of the much more abundant and valuable meal. And soy is what farmers in the Midwest are accustomed to growing in rotation with corn.

Lester Brown seems to love sugar beets. But he clearly has not studied its economics, which are poor. The industry survives here in Europe only thanks to government support. (Unlike cane, for example, there is no bagasse that can be used to co-generate electricity.) A couple of years ago, the USDA's Economic Research Service looked once again at sugar-based ethanol in the United States, and declared it uneconomic (even with the $0.51/gallon blenders' credit).

And don't forget, sugar beets are a row crop, which means they exert a heavy toll on the soil. A lot of soil is displaced when it is harvested, also. Here in France, the highway authorities have to erect signs out in the northern French countryside every autumn, warning motorists to watch out for slippery patches of mud (and squashed beets) that cover the road in places.

Finally, the net (non-fossil) energy yield for switchgrass -- still only produced in pilot-scale plants -- may be much higher than for corn, and half as good as sugarcane, but the process is much more capital-intensive, which drives up its unit costs considerably.

These are only my personal opinions.

]]> David

Um, these numbers say nothing about relative production costs. (And Journey to Forever has a longer list of oilseed yields.)

One of the reasons (besides subsidies) that soy biodiesel exists is that the oil was initially a by-product of the much more abundant and valuable meal. And soy is what farmers in the Midwest are accustomed to growing in rotation with corn.

Lester Brown seems to love sugar beets. But he clearly has not studied its economics, which are poor. The industry survives here in Europe only thanks to government support. (Unlike cane, for example, there is no bagasse that can be used to co-generate electricity.) A couple of years ago, the USDA's Economic Research Service looked once again at sugar-based ethanol in the United States, and declared it uneconomic (even with the $0.51/gallon blenders' credit).

And don't forget, sugar beets are a row crop, which means they exert a heavy toll on the soil. A lot of soil is displaced when it is harvested, also. Here in France, the highway authorities have to erect signs out in the northern French countryside every autumn, warning motorists to watch out for slippery patches of mud (and squashed beets) that cover the road in places.

Finally, the net (non-fossil) energy yield for switchgrass -- still only produced in pilot-scale plants -- may be much higher than for corn, and half as good as sugarcane, but the process is much more capital-intensive, which drives up its unit costs considerably.

These are only my personal opinions.

]]>