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Comment by Joakal | Hacker News Reader

Is it more efficient than deriving ethanol from corn over the same land size?

Yes. algae can be harvested multiple times daily, corn is seasonal.

Also, algae has a much larger percentage of oil to its mass. I've read some types can be close to 40% oil.

Furthermore, algae's use as fuel doesn't impact food prices, or the prices of goods made from the many millions of corn byproducts. Arguably, it makes a lot more economic sense than corn-based ethanol in the long run.

One counter-argument I've heard is that we wouldn't be using land to grow algae in the first place if we weren't growing it for fuel. Whereas we're already growing more corn than we need. So the opportunity cost of growing algae is therefore taken into consideration. I'd argue that this logic assumes we'd be growing algae and/or corn on the same plots of land, which seems to be inaccurate. I don't think a zero-sum economic analysis can be done, given that they are not viable substitute crops in any given space. Furthermore, I don't think we're growing enough surplus corn to cover total fuel consumption needs without dipping into the food and industrial supply.

Finally, yes, algae is a more efficient raw material for fuel extraction than corn is.

Also, the US government does not currently subsidize the production of algae like it does corn.

I thought the idea was to make ethanol from the cellulose, not from the oil? (In corn, it's the sugar you use.) Plants have a lot more cellulose than sugar, so if you can utilize it for making ethanol, you tap a much larger potential source.

Cellulose is a horribly difficult material to do anything at all with. After drying it can be burned to produce heat, and that's pretty much all that's ever been done to it.

Well, it certainly isn't ready for prime time, but you can definitely make ethanol out of it: http://en.wikipedia.org/wiki/Cellulosic_ethanol

And when you convert algae to fuel you're not taking food off the table, as you are with corn. The impact ethanol has on driving up food prices is the almost exclusive reason why I avoid using it.

Folks are going to flood fields with salt water to wildcat algae for fuel plants. I know I would if I lived near an algae plant and had the land.

The article claims there is no erosion issue - so its better on the environment. I disagree - its entirely possible to grow algae and damage the environment at the same time.

This isn't mentioned anywhere /near/ often enough- no one is going to be repurposing wetlands for this.

I thought I read once scheme was to run a water pipe into the desert and build your algae ponds their? No farmland, lots of sun. Not sure about it though.

Lots of hot desert, salt water and pipeline/shipping infrastructure in the Gulf states. So, once again, the Saudis win? :)

Desert is an ecosystem too, and a fragile one. It can also be destroyed, and would definitely suffer if all that sunlight was "farmed away".

Most of the US corn goes to cattle feed and not food directly, and the only reason that makes sense is because corn is so cheap. (It's actually not a very good food for cows, who are adopted to eating grass.) So maybe you are taking food off the table, but if we cared about cheap food we wouldn't use the corn to grow cattle anyway. Any vegetarian will tell you in a heartbeat that eating beef is kind of like eating oil, because most beef was raised on corn and growing corn is like an inefficient method of transforming oil into food due to the large use of petroleum-based fertilizer.

For an interesting story about this, check out "The Oil We Eat" by Harpers (http://www.harpers.org/archive/2004/02/0079915).

I was just calculating how much land area would be necessary. Given the stats in the OP: need 18M gallons/day, 300 acres=1M gallons, this works out to 1971000 acres = ~3000 sq miles = a square about 55 miles on a side.

Yes, because they're going to be doing it in New Mexico, on land that can't be used for crops.

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