What greene energy can't do.

[Betonov]

Originally Posted by kraznyi_oktjabr

Do you mean algae based fuel developed by EADS?

That's one option. But those algae need to be fed, bringing us to another dillema of food vs fuel like with biodiesel.

I will try to keep out of this, but let me just say this:

Originally Posted by Albert Einstein

Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.

TRUE!

[August]

Originally Posted by Betonov

That's one option. But those algae need to be fed, bringing us to another dillema of food vs fuel like with biodiesel.

I thought the algae were supposed to eat carbon?

[kraznyi_oktjabr]

Originally Posted by August

I thought the algae were supposed to eat carbon?

They use solar energy to synthesize carbon dioxide (CO2) and dihydrogen monoxide (H2O, commonly called water) into organic material usually but not always sugars.

Ofcourse they also need phosphate, nitrogen, sulfur and other chemicals as building blocks but they get their energy from photosynthesis. What we humans want to do is to process algae to hydrocarbons (molecules containing carbon and hydrogen) which can be burned to run our little toys like cars, aircrafts, ships and power plants.

[vienna]

I will try to keep out of this, but let me just say this:


Quote:
Originally Posted by Albert Einstein
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.



TRUE!

Wow, I didn't know Einstein is an active of SubSim...

Well, suprise!

[August]

Originally Posted by kraznyi_oktjabr

They use solar energy to synthesize carbon dioxide (CO2) and dihydrogen monoxide (H2O, commonly called water) into organic material usually but not always sugars.

Ofcourse they also need phosphate, nitrogen, sulfur and other chemicals as building blocks but they get their energy from photosynthesis. What we humans want to do is to process algae to hydrocarbons (molecules containing carbon and hydrogen) which can be burned to run our little toys like cars, aircrafts, ships and power plants.

So it's not like biodiesel then where we're having to make the choice between using crops for food or fuel?

So it's not like biodiesel then where we're having to make the choice between using crops for food or fuel?

The only real choice most farmers make is which product will pay most for the least amount of input.
If the money is in cotton then people will choose to grow cotton as a crop instead of food, if the money is in corn for diesel they will grow corn for diesel, if the money is in corn for fructose syrup then the people will grow obese.

[kraznyi_oktjabr]

Originally Posted by August

So it's not like biodiesel then where we're having to make the choice between using crops for food or fuel?

Yes. What you (in theory) need is a large pool of water for growing algae therefore you can put it into middle of desert if necessary. What will be biggest problem in growing algae is need for sunlight which means that pools must be quite large in surface area you can not just dig deeper hole for it. Another trouble maker is availability of water. Propably most practical solution would be to locate growing pools in seaside location so that seawater can be directed to pools as necessary.

I don't know what exact needs for growing are they vary highly because there are a lot different algae species with different needs. If we consider only sunlight and water need and in my opinion important thing - putting it somewhere else but Middle East - then two of my favourite locations would be coastal areas of California, USA and southern coastal areas of Spain.

All above is in theory. How it will work have to be seen but I really hope that this will work and we will get it relatively soon.

EDIT: EADS has already flown algae fuel powered helicopter so the questions is no longer "can you do it" but "can you do it at commercially viable cost"? I hope that EADS and its competitors in this field can make industrial scale production feasible.

EDIT#2: I don't know for sure but I'm worried that biggest problem is not in efficiency of growing algae but in efficiency of processing it to fuel usable in cars, aircrafts and so on.

[TorpX]

Originally Posted by Blood_splat

Saw this on Reddit. Talks about Thorium, an alternative nuclear fuel.

This Thorium nuclear idea sounds promising, but I have to ask why there have not been any attempts to put one into operation. Are there problems that make it impractical?

[TLAM Strike]

Originally Posted by TorpX

This Thorium nuclear idea sounds promising, but I have to ask why there have not been any attempts to put one into operation. Are there problems that make it impractical?

From what I understand the first one is more expensive to start than a normal plant. However it gets cheaper once that first one comes online because it can help process basic thorium in to thorium-232 which necessary for it use as fuel.

[Sammi79]

Originally Posted by TorpX

This Thorium nuclear idea sounds promising, but I have to ask why there have not been any attempts to put one into operation. Are there problems that make it impractical?

The proof of concept was done in the late 50's early 60's and was successful. The primary problem of impracticality is that it is impossible to breed plutonium from the thorium fuel cycle - which basically consists of neutron activation of inert thorium 232 to transmute it into uranium 233 which is the fissile energy producing fuel in this cycle. Plutonium is the easiest fissile element with which one can produce a bomb although more unstable than uranium because of the varying qualities of its isotopes though both plutonium and uranium require a similar mass to become critical. Uranium 233 can be used for a bomb, but it requires a much larger mass (or much greater pressure) to become critical, and is a powerful gamma (ultra high energy photon) emitter meaning it is extremely dangerous to handle in any amount as opposed to plutonium or uranium in sub-critical masses which can both be relatively safely held in your hand for short periods of time (certainly not advisable but less radiation than a chest CT scan for example) and are relatively easy to 'hide' as opposed to the very bright 'glow' from uranium 233 which is very easy to detect even in trace amounts. Also in the traditional uranium cycle only about 17% of the uranium undergoes fission, whereas in the thorium cycle roughly 90% of the bred uranium 233 is burned so it is much more efficient. Because thorium itself is not radioactive, does not decay over time there is a lot more of it on the planet than uranium and is therefore cheaper, easier and safer to mine and purify.

So in my opinion it seems fairly obvious the technology was shelved as interesting but useless for proliferation - which was a big issue during the cold war. Lots of anti nuclear folks do argue that if the tech was any good we'd already be doing it but I think political and economic forces over the last half century strongly suggest otherwise. There is the issue of requiring a large amount of energy for the neutron flux to breed enough uranium 233 before the reaction becomes self sustaining but this would be recouped quickly once operating at optimal output.

There are also some very interesting new ideas for next generation nuclear power plants like liquid cores (already 'melted' so no meltdown possible - again not suitable for proliferation) which could be made to work with both uranium and/or thorium solutions as well as impressive negative feedback safety systems like freeze plugs (if the core melts, the freeze plug melts and the liquid is drained into several separate reservoirs thus dividing the mass and dropping it below criticality etc.

I like the liquid core idea, because if the reaction starts increasing too fast, the temperature increase would generate gaseous bubbles or voids within the core immediately slowing the reactions down, another negative feedback concept. Combine that with a freeze plug and use thorium bred uranium 233 as a primer then you have a system that would shut itself down without human interaction in the case of a runaway chain reaction, which is impossible to make bombs from, and could thereafter burn any fissile element (particularly previously generated nuclear waste) that can be made into solution and pumped into the core as fuel. There are however very serious engineering problems yet to be solved for radioactive liquids and methodology and is probably a long time away yet. A lot closer than fusion though!

I'm sure some folks will disagree with my enthusiasm for nuclear power generation and I well know and understand all the arguments for and against of which there are many on both sides. My enthusiasm is only for the science however, and the pursuit of knowledge. In some places on this earth (not all by any means) I think nuclear power generation is the most sensible option. Regardless if the subject either fascinates or disgusts you, you may find this link interesting :

https://en.wikipedia.org/wiki/Natura...ission_reactor

Regards, Sam.