[texaslabrat]

The efficiency of photovoltaics is closely tied to the wavelengths being collected. Since x-rays are so much more energetic, they have the potential to use a far larger array of bandgaps than visible light…so I have no trouble believing that 80% efficiency is possible in theory…with a lower % efficiency most likely being achieved in practice.

I can’t point you to a x-ray photovoltaic technology meant for power production because, up to now, there hasn’t been a need for anyone to build one. However, there are a great number of x-ray detector research projects around the world. Some use scintillation, others use direct photovoltaic effects, and some a hybrid of the two. Here is a patent of one such project:
http://www.freepatentsonline.com/7161155.html

There are a lot more out there that some google searching can dig up. But, taking this one as an example, they claim a collection efficiency of 50%, and production of 276 electrons/keV (correct me if I’ve read it wrong). I’m not an expert in this field, but at first glance this seems like the type of tech that could be adapted to power generation. So while it’s not proof positive that power production from such a mechanism is feasible, at the same time it represents a marked lack of concrete proof that would tend to disprove such a device.

Anyway, like I said before, I’m going to withhold the majority of my “judgment” until the patent information becomes public and can be subjected to a more general review. But from what I’ve seen so far, I’m encouraged.

[texaslabrat]

Transmute wrote: no no not even theory, they admit they need x-ray conversion: see this thread: https://focusfusion.org/index.php/forums/viewthread/107/

I understand that. However, you are making some assertions that a heat engine (Rankine or otherwise) would be necessary for net positive energy generation. That’s where we differ. I think everyone here understands that x-ray conversion has always been part of the plan. And that isn’t nearly as bleak as some are making it out to be..there has been a ton of research into X-ray detectors in photovoltaic modes of operation that I’m sure will be leveraged. This is not some new untested science here..just a new application for stuff that’s already here. Not only that, but if they are successful in capturing upwards of 90% of the ion beam energy (which “they” say is reasonable)…break-even occurs at x-ray conversion of only 22%. Hardly a “high-efficiency” requirement for x-ray conversion. The proof is the pudding, of course..but so far I haven’t encountered any hard evidence to cause me to doubt “The Plan”.

Skepticism is a healthy thing. But defeatism before we even see the details from the patent application is not.

[texaslabrat]

Good point..and I’m indeed working under the assumption that DPF will succeed as intended. If it requires integration with traditional power generation heat engine cycles to be energy positive…it won’t necessarily be a failure but its impact on our society will be severely blunted. Here’s to hoping things work out according to theory 🙂

[texaslabrat]

I

[texaslabrat]

I went to the site too…and the ideas for extracting energy from periodic motion (eg waves) are interesting. However, the claims of perpetual motion and “something for nothing” energy generation are entirely misguided. Klaudio, you said you had your “engineer friend” look over your calculations and he thought they looked good? I suggest you find another technical reference. I did a quick energy analysis of the proposed system and it suffers a substantial energy deficit (no surprise there..). Both scenarios of filling the bell completely with air at the bottom of it’s cycle (100m…approx 10atm) and filling it just enough to start an upward motion (and therefore relying on linearly decreasing pressure to increase the upward force as it continues to ascend) result in substantial net input of energy to maintain the cycle. The “full air bell” scenario comes out to a deficit of about 8100 kJ…and the filled-just-enough scenario comes to about 1465 kJ deficit. I can post the full calculations if anyone is interested…I’ll leave it at just these final results for now if no one cares since it’s a heck of a lot of typing :p All of those calculations don’t take into consideration any friction losses and the like…and I used an isothermal compression scenario for the work required for the air because the process becomes isothermal by default since it will be in virtual direct contact with a huge isothermal heat sink in the form of the bell and the surrounding water.

Also…FYI Klaudio…standard atmospheric pressure is not 101300 kg/m^2 but rather 101300 N/m^2 (1 kg exerts 9.81 N at the earth’s surface) … although that wasn’t the biggest problem in your calculations. Anyway, long story short (too late, I know…) Homer Simpson can rest assured that the laws of thermodynamics are still being followed in the house (http://www.thesimpsonsquotes.com/characters/homer-simpson-quotes-13.html)

[texaslabrat]

OK 🙂 Here’s a few from a variety of scientific and pseudo-scientific (*cough*wikipedia*cough*) links:

http://www.agu.org/meetings/os06/os06-sessions/os06_OS35M.html
http://www.scor-int.org/2006GM/2006-Iron.pdf
http://carbonsequestration.blogspot.com/2006_05_01_archive.html
http://en.wikipedia.org/wiki/Iron_fertilization
http://news.com.com/Seeding+the+ocean+to+capture+carbon/2100-11395_3-6182861.html?tag=nefd.top
http://www.agu.org/revgeophys/chisho00/node3.html
http://www.google.com/search?q=2004+EIFEX+results&hl=en&start=0&sa=N

[texaslabrat]

Seeding the “desolate zone” of the ocean with iron is probably the most cost-effective way of removing CO2 from the atmosphere…recent experiments show a fixation rate of 300,000:1 CO2-to-Fe. While I am not an expert on the latest commodity prices of iron…it seems that ~3000 tons of iron per year could feasibly be used in such a fashion pretty cheaply. So cheaply that the $25 million prize would actually be a pretty nice incentive….coupled with the carbon credits that could be exchanged for a profit. There’s at least one company who plans to make a business model out of exactly this process.

Direct sequestration via liquefaction/injection seems to be a “brute force” approach…no matter the energy source being used it will never be efficient enough to use as a global-scale solution in the time-scale that we’re interested in. Leveraging nature’s own mechanisms will nearly always yield orders of magnitude in improvements of efficiency and costs since the sun provides the energy to drive the processes. Focus fusion’s best contribution in this area probably lies in the elimination of future CO2 emissions over time as fossil fuel energy sources are phased out over the next few decades.

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