http://en.wikipedia.org/wiki/World_energy_resources_and_consumption

One Tenth of New Mexico would only receive 4*10^20 J of sunlight in a year, and the US uses 1.2*10^20 J per year, so he's assuming an efficiency of 30% for the whole process, including photosynthesis, refining and transportation of the final product? I call bullshit. Photosynthesis is typically less than 1% efficient, and even the most efficient known species of algae convert light to biomass at 3-6% efficiency.


Humans use 5*10^20 J per year, and over 80% of that is fossil fuel.

Only 4*10^24 J per year of sunlight reaches the earth (do the math)

Assuming photosynthesis efficiency of 1% and fermentation+distillation+transportation efficiency of 25%, you would have to cover 1/25 of the earth's cross-section with biofuel-growing (that's at least 1/4 of the total arable land, depending on latitude) to cover the world's energy needs. Burning biofuels still produces atmospheric pollution like ozone and nitrogen oxides. Elecrtic cars will pollute the atmosphere less than any biofuel internal-combustion car.

Anything based on photosynthesis is going to be wildly inefficient compared to solar thermal generators.

*algae

Link to CNN article.

http://www.cnn.com/2008/TECH/science/04/01/algae.oil/index.html

From YouTube description:

We came across this three-toed sloth struggling to cross the road between Arenal Volcano and San Jose. We formed a loose cordon to keep cars from running the guy over. He made it, slowly.
Story and photos at dolanbrau.com
Look for 'costa rica and the galapagos'.

To answer some questions in the comments:
a) it took 5-10 minutes for the sloth to cross half the road
b) it was covered in bugs and algae and had long sharp claws - no way were we going to pick that thing up

The US has enough coal to ween itself off of foreign oil completely. Coal can be turned into cleaner burning gasoline and diesel [1]. We can also build modern cleaner coal fired power plants and use algae bioreactors to reduce the NOx and Co2 emissions, and the algae from those bioreactors can then be turned into biodiesel [2].

they really get ALL their energy from symbiotic algae? that would kindof make them the only (really) motile autotrophs anywhere wouldn't it?

oooh, can I just be a nob head and say that blue/green algae are not algae. They are cyanobacteria. Sorry, biology geek here.

Chaucer i'd like to try and answer your posts. The best i can.

#2 i don't know right now but I'll try to find an answer.

#3 Just because something heats up doesn't mean it expands just means there's more energy in the system that's all.

#4 The fact that the earth was covered in salt water isn't guess work, and the blue-green algae is still around today. Oxygen is one of its natural byproducts. More Oxygen is put into the atmosphere by these same algae today than all of the forests in the world combine. It also has a cousin usually referred to as the red tide. It kills all of the fish in the area because it consumes all of the oxygen and gets rid of it into the air and not back into the water.

#5 If mass is gained then gravity must all so increase. They are bound together by the law's of physics. F=mg (force=mass*gravity) That fact alone destroys this idea so completely. We know what the mass of the earth and the moon are and can build models to show there effects on each other. And every year the moon drifts 30cm away from us. That's not much but in 5 million years we will no longer have a moon. If this idea was correct the moon should be getting closer each year because of the expansion and the increase in gravity over time. So for this to be true no mass is gained but the moon should still be getting closer to us because of the expansion but its not. The Apollo missions put mirrors on the moon and ground based lasers get shot at them then the time to return is calculated and every year its drifts 30cm away from us. So wave good bye while you still can.

Another point i just thought of is the fact that the core of the earth is active and produces and electromagnetic field around the earth that blocks the suns radiation as best it can. if the core or the earth were increasing in size wouldn't that field also increase at a constant rate as apposed to the one we have now that fluctuates and has switched direction at least 3 times now. We can tell it has changed poles because of molten iron deposits from volcano's millions of years ago have there own magnetic fields backwards and some with very little fields at all.

Its an interesting idea but nothing more. It was fun to think about counter arguments to it.

You've gotta be Aljoking. I'd rather watch algae or Al Bundy.