Domain: doe.gov
Stories and comments across the archive that link to doe.gov.
Comments · 1,522
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The IEA and Other Resources
One of the first sources quoted by the reviewer is the International Energy Agency, a forum for 26 industrialized countries. For those wo want to tap deeper there are a lot more - and diverse - statistics out there. For example the IEA's statistics on world consumption vs reserves are different from those of OPEC, and even different from state-run BP's Statistical Review of World Energy, which I consider more moderate than either of the two previous sources. The US Energy Information Agency site is also very comprehensive. Check out their Country Profiles section for comprehensive info on oil operations the world over.
http://www.energyspot.org
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Re:Something good may yet come out of this
Seven times? That sounds a bit high . . .
From the U.S. Dept of Energy: (In 2001) Total Per Capita Per $/GDP (BTUs x 10^15) (BTUs x 10^6) (BTU) US 97.05 341.8 10,736 Germany 14.35 174.3 5,312 France 10.52 177.8 5,805 Italy 8.11 140.0 6,618 UK 9.81 164.8 7,349 Japan 21.92 172.2 3,879 China 39.67 30.9 35,619 -
The skinny about the militaryUnfortunately, the Energy Information Agency does not break out the military, or even the government, as a separate sector. However, if you compare the number and size of the ships of the Navy, vehicles of the Army, etc. to the number in the private sector, I'll bet that you'll find that the consumption they require is relatively small.
The Navy has an oil reserve in Alaska. We don't need it yet, and nuclear aircraft carriers and submarines never will.
Last, there's a lot of room to increase the efficiency of the military. There was talk about a hybrid HMMV replacement several years ago, with stealthiness (low thermal and audio signature) being a military advantage at least as great as the need for 50% less fuel. Hyperbar diesels could replace gas turbines in an M1A1 replacement, with probably a similar improvement. We could power ships with powdered coal if we wanted to, at some cost in range. I have not had the opportunity to study the issue in depth, but it doesn't look terribly difficult to me. The one intractable use is for aircraft fuel, but if you can divert large amounts from the land and sea to the airborne users it shouldn't be that big of a deal; a barrel is a barrel is a barrel no matter where you save it.
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Green Transportation-Puff the magic boiler.
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Green Transportation?Who would have guessed that China would lead the way in green transportation?
Uhh, until we build a lot more nuclear, solar and wind power plants, electricity in most areas of the world (including the US) still comes overwhelmingly from fossil fuels.
US DOE stats show that nearly 80% of electricity in the US comes from fossils fuels. And because electical lines loose power do to resistance, and batteries are not perfect, electically driven bike are not very efficient.
The bike is polluting, maybe hundreds of miles away, but it is still polluting.
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Ever thought of checking it out?
I have also read estimates that the US may have 500 years worth of nuclear fuel.
Fine, let's put a number on it.Nuclear power usage hasn't been that much so far.
Before I would answer your last question I would want to read studies about what would happen if you had MANY of these kinds of plants operating for YEARS AND YEARS doing what you described to a large degree.
As others have correctly pointed out there is a price for everything.
The USA currently has roughly 900,000 megawatts of electric generating capacity. Let's assume for the sake of argument that we will use this amount of power 24/7/365 and that it's 100% nuclear. The electric consumption is thus ~330 million megawatt-days per year, or ~8 billion megawatt-hours per year. (This is about 2 times 2002 US consumption of 3.858 billion MWH, so it's fine for this analysis.)
Next, let's assume that this energy is generated using HTGRs which operate at 40% thermal efficiency and that they can get 50,000 megawatt-days of heat out of a ton of uranium. This is 20,000 megawatt-days of electricity per ton, so the annual uranium consumption would be 3.3e8/2e4 = 16,500 tons per year. Do this for 500 years, and you'd have 8.25 million tons of spent fuel.
If you assume that the spent fuel winds up in a form which has a bulk density of 2.75 g/cc (slightly less than the average for surface rocks, and a figure that I picked for convenience in calculating) the total volume would be 3 million cubic meters. This would fill a rectangle a mere 500 meters square by 12 meters high - FOR 500 YEARS OF ENERGY PRODUCTION. And by the time the last of it was produced, the first of it would be safe to hold in your hand for hours at a time.
Is it any wonder that I think the whole radwaste problem has been shamelessly overhyped by the political left?
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Not true either
As of February 2004 (the most recent I could find), Mexico and Canada were tied then Saudi Arabia, by country. Looking over the current year it would seem to average out to be just about equal between Mexico and Canada (16%) with Saudi Arabia slightly behind in third place (15%). The point being that North American sources of oil provide 32% of the total oil imported, more than you'd realize. Here is my source.
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Re:How do you tell...
Hmm... I see it different, also from the DOE:
"In the first three quarters of 2003, the United States imported more oil (including crude oil and petroleum products) from Canada than from any other country. During the same time period, the United States also imported about 2.5 trillion cubic feet (Tcf) of Canadian natural gas, representing 87% of total U.S. natural gas imports."
and
"This makes Canada the top petroleum supplier to the United States and the third-largest supplier of crude oil imports (behind Saudi Arabia and Mexico, and ahead of Venezuela). Canada has been the top supplier to the United States of refined petroleum products, including gasoline, jet fuel, distillate, etc., since 1996."
Here is the link -
Re:How do you tell..."provides the most oil and gas to the US"
This isn't correct. It's Saudi, Mexico, then Canada. Then, Venezuela, Nigeria, Iraq, U.K.... -
Re:Good suplement, poor replacement
At the moment it is only twice as expensive as diesel here in the US
bullshit.
In February of 2004 (the most recent date I could quickly find these figures), when regular diesel was selling for around $1.60 per gallon, biodiesel fuel was selling for about $1.80 per gallon (source) The current price of diesel is $1.74 in the US. I would call that slightly more expensive, not "twice as expensive". Additionally, some biodiesel facilities are beginning to use waste restaurant grease which will reduce the price further. Here is a book that teaches you how to make biodiesel in your own backyard for pennies per gallon. (of course, there's always the "how much is your time worth?" argument, but the amount of time actively working is low, most of the time commitment is waiting)
all of our fertilizers are fossil fuel based
bullshit.
No really, ever heard of 'manure' as fertilizer? or perhaps all of our manure producing livestock are now fed fossil fuels?
growing enough biofuel to replace all the world's oil usage would require all the arable land on the entire planet
bullshit.
I won't even bother explaining how rediculous this one is.
Vegenergy is a company starting up in Atlanta, GA to produce biodiesel from waste restaurant grease. They have some info on the website, like a some common myths about biodiesel. Look around for real information before just spouting garbage. No wait, this is slashdot, nevermind, continue spouting ... -
Where do you think electricity comes from???
Based on primary energy source, coal-fired capacity represented 43 percent (260,990 megawatts) of the Nation's existing capacity (Figure 1). Gas-fired capacity accounted for 19 percent (117,845 megawatts); nuclear, 14 percent (86,163 megawatts); renewable energy sources,2 1
Inventory of Electric Utility Power Plants in the United States 2000
Photovoltaic Industry Statistics: Market Share
Try alchohol based oxygenates like ethonol. -
Re:Ironically...I was talking about the driver compartment in order to stop the vehicle.
What are they going to do after they stop the vehicle? It's escorted by armed guards, and tracked by satellite.
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Whatever
'Atomic storehouses, vulnerable to terrorist attack, will be emptied of their radioactive loads,'
Hmph, to put it where exactly? -
Re:Well...
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More wind than Kansas can use
In the US, Kansas alone is prime for an install base of 121,900 MegaWatts, http://www.awea.org/projects/kansas.html !
That would be "installed base", if that's what you meant (which you probably didn't). I bet you meant "potential nameplate capacity".Total generation capacity in the USA in 2002 was a bit over 900 gigawatts. 122 GW is a lot more than Kansas could use, and much more than could be transmitted out of the state by conventional means. To make productive use of this much power you'd have to get fancy, such as by promoting an economy based on zinc-air or aluminum-air batteries and using excess wind to refine ZnO2 and Al2O3 back to metal during times of surplus. You could move bulk powdered or pelletized oxides and metal using tank cars or even pipelines.
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Re:Corn is a very poor crop to use.
We know. Somebody has to post this in EVERY thread on alternative fuels, but it's not relevant. Ethanol from cellulosic biomass bears very little resemblence to corn ethanol production in environmental or economic impact. See my post here or search through my posting history for lots more good information on the subject (I've written humongous posts on this before, but I'm too lazy to look them up now - or start reading here for useful scientific, economic and environmental studies from the DOE.
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Re:Run for your life!You have got to be kidding.
I really can't understand how you could be afraid of being bombed while holding such a misunderstanding of American politics. Not to be all arrogant, but if the world is going to hate America, I will demand that they have half a clue what the hell it is they hate.
1. Colin Powell is the Secretary of State. He represents the US in the world arena.
2. Powell and Rumsfeld don't have one tiny thing to do with each other unless the US is already attacking a foreign nation. That is the ONLY relationship they share.
3. Rumsfeld never came up with "excuses". He works for the President's administration. He comes up with plans for military action. He doesn't have anything to do with the political situation except to play TV Star with the reporters.
4. What perversion of good sense makes you think that a company which represents one of the foundations of the American economy can take such a beating internationally and the Secretary of State would twiddle his thumbs? This strikes me as not only ignorant of politics but of world history for the last 300 years as well.
5. Even the dimmest of wits who believe against all odds that the US attacked Iraq for oil (despite the fact that the Persian gulf contributes not even 25% of American oil imports, and of that oil, almost all of it comes happily from Saudi Arabia) could not explain what American could gain by attacking Europe.So in conclusion, you're scared of America attacking Europe, and I'm scared of what would happen if Europeans had laser beams for eyeballs and mechanical arms that could cut a(n) (American) car in half. My fear is slightly more likely to be realized than yours, thanks for asking.
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Re:Might cost more for some of us.
Biodiesel and Bioethanol are not the same thing. One of the reasons that it can take a lot of energy to produce fuel-grade ethanol is that it needs to be distilled (just like vodka) and that's a relatively energy-intensive process.
Biodiesel uses a very different process (see this portion of the document mentioned by o'reor.
I don't think you can assume that teh energy costs are the same for the two different fuel types. (Plus, a some of the ethanol/biodiesel actual gets mixed with traditional gasoline and diesel for use in cars rather than being used straight.) -
Re:Post a link!!!Here is the DOE site for alternative fuels.
There is a comparison table (PDF format) stating the following:
"Biodiesel is domestically produced and has a fossil energy ratio of 3.3 to 1, which means that its fossil energy inputs are similar to those of petroleum."
The whole document (and the site) make a very intersting read.
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Re:Post a link!!!Here is the DOE site for alternative fuels.
There is a comparison table (PDF format) stating the following:
"Biodiesel is domestically produced and has a fossil energy ratio of 3.3 to 1, which means that its fossil energy inputs are similar to those of petroleum."
The whole document (and the site) make a very intersting read.
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Fanning the fires of Ignorance...
That's a nice posting and all, except for the fact that a 13 year study by University of Pittsburg found there was no statistical increase in occurrences of cancer around the Three Mile Island plant in Harrisburg PA.
Secondly, the reason you cite for not touching the Challenger fragments was because of (1) the temperature of the metal on re-entry and (2) the hazardous fumes from the aforementioned burning material. Although a local Texas sheriff claimed there was "radioactive material on board" (picked up by reporters with little fact checking), NASA has since said that the only radioactive material on the shuttle at the time were in the smoke detectors.
How do you check for deaths by radiation? By measuring the increase in cancers with respect to a "control group" of those that were not exposed to the radioactive source. For example, population of Seattle vs Chernobyl. If cancer rate is statistically higher, then you're golden.
Oh, and we have a great way to store radioative waste, it's called Yucca Mountain. Find a mountain of volcanic minerals, surrounded by more mountains and deserts, with an non-existent water table in a non-populated area, on government land with a 110 mile radius. Seal the crap underground, and post a guard for the next 6,000 years.
Hell, in another 100 years, we may find methods to "refine" the nuclear waste for more fissionable material, much like we do now in extracting uranium from ore. Just as we aren't going to run out of oil, we're going to run out of cheap oil, then we retool for more extraction. Our children's childeren will be thanking us for taking the time to concentrate all the material into one site for easy processing, just as we build trash-to-steam generating plants (sorry, "reclamation centers") at trash dumps today. -
Re:No it's not.
So if St. Helens was the equivalent to 40 coal-fired power plants, does this mean that Mt. Pinatubo was the equivalent to the output of over 400 hundred coal-fired power plants?
Does this mean that the 1566 coal-fired power plants in the U.S. is equal to four explosions from Mt. Pinantubo every year?
Buddy, you aren't doing a very good job of reassuring me...
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Fact Checking
Since France went nuclear, the country experienced a five fold decrease in air pollution.
My bad. This is what I get for not doing better fact checking. This number is greatly overstating the matter.
From The Energy Information Awareness division of the U.S. Department of Energy: "France's commitment to the use of nuclear power has allowed the country to keep a lid on its carbon emissions, since nuclear power emits no carbon or other greenhouse gases. Since 1980, when France emitted approximately 136 million metric tons of carbon, the country has cut its energy-related carbon emissions by just over 20%, to 108 million metric tons in 2001. By contrast, carbon emissions by the United States over that same time period have grown by almost 22%, from 1.29 billion metric tons of carbon in 1980 to 1.57 billion metric tons in 2001."
That sounds more correct to me sice automobiles are a (the?) major contributor to air pollution in most industrialized nations.
"France's move towards nuclear energy and away from fossil fuels such as coal is clearly evident in its reduced level of carbon intensity. In 2001, France's carbon intensity was 0.06 metric tons of carbon per thousand 1995$--exactly half the country's carbon intensity level in 1980. France's level of carbon intensity in 2001 compares favorably with its neighbors in western Europe, as the UK (0.12 metric tons of carbon per thousand 1995$), Spain (0.11), and Italy (0.10), and Germany (0.08) all posted higher levels of carbon intensity than France in 2001." -
Re:Reasons for power blackouts
In places like France, it's just too expensive to have air-conditioning.
According to the US DoE the domestic electricity prices ($/kWh) in 2000 were 0.102 in France and 0.082 in the US, not counting state taxes in the latter case. That doesn't seem like a sufficiently large price difference to explain the lower use of AC in France.
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Re:HUH???????
Actually, flex-fuel vehicles that run on any mixture of gasoline and ethanol up to 85% ethanol are already hitting the market in mass quantities, under the radar. Check out all these cars with the flex-fuel option. On some models, it's even standard.
That's 19 just in 2004. With computerized fuel injection it becomes pretty trivial to modify cars so they can take advantage of those nice environmentalist tax incentives(even if the purchasers of these cars never runs it on e85) -
Re:Burning fuel isn't a good ideaIf that's the case, then I stand corrected. However, it sounds like this would require massive infrastructure change for most users of gasoline to switch over.
Oddly enough, I was about to launch into a counterargument having to do with greenhouse gas emissions and the energy balance comparing biodiesel with fossil fuels, but it appears that biodiesel produces less CO2 and has a more favorable energy balance than petroleum diesel.
Interesting. I wonder why we are sacrificing thousands of human lives and spending hundreds of billions of dollars to control a far away petroleum producer given the data in those two documents. Conspiracy theories, anyone? It might be useful to inject this into the public discussion of the US presidential campaign.
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Re:Shame
I am a little skeptical of your estimate of the generating capacity. Peak power demand for a modest city is about 2 kW per person, so a power plant would have to generate 500 megawatts to supply a city of 250,000. Each unit at Three Mile Island had a capacity of about 800 megawatts. Are you saying that each power plant on the Enterprise is more than half the size of Three Mile Island?
Also, with all your confidence in Navy machinists' mates, I wonder how all those well-trained ex-Navy personnel allowed so much corrosion to attack the reactor vessel head at the Davis-Besse plant. According to the NRC, it was because they were not adequately trained, supervised, or audited.
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Re:Assumptions of grid design are becoming falseSorry for the confusion . . . The link you provided for DSM states that: Demand-side management (DSM) programs consist of the planning, implementing, and monitoring activities of electric utilities that are designed to encourage consumers to modify their level and pattern of electricity usage.
It doesn't state that the grid has the right to shutdown non-essential usage (Sidebar - Wouldn't cutting non-essential "supply" actually be "supply side management"?). The definition that you've contextualized is quite interesting. A number of questions immediately come to mind. Is a system like this being implemented elsewhere? How would a tiered system be implemented logistically on the existing grid? Whose use would be considered "non-essential" and how would one differentiate essential from non-essential? Pricing/Market pressures? Regulatory guidelines? A combination of these?
Also, a fault in the industrial sense is a root cause of a problem. A last resort to save the grid is a resultant action to mitigate a fault (however I empathize with you in that the way the grid is currently designed causes a rather extreme all or nothing response to mitigate the aforementioned problem). During HAZOP (Hazard and Operability Studies), FMEA (Failure Mode and Effect Analysis), and FTA (fault tree analysis) faults are defined as root causes of problems. Actions to mitigate faults whether right or wrong, ideal or extreme are not faults (though this does not mean that these actions are not problematic or that there is not a better way of mitigating the fault).
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Re:If it's more of a worry thanHe's installing a hard drive, not an air conditioner. How much electricity does a hard drive use? A WD Raptor uses less than 10 W peak (see here). To be generous, assume it uses 10 W at all times. That is approximately 87.6 kW*hr for an entire year. According to this page, the avg residential price for electricity is 8.62 cents per kilowatt-hr.
He will use $7.55 of electricity for an entire year. I don't think that will break him.
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Assumptions of grid design are becoming false
Moreover, grids are deliberately designed (1950s or not) to channel energy where it's needed. This prevents overloading or underpowering.
I'm sorry, but the second sentence is just false. The assumption of the grid is that there is always sufficient generating capacity to meet the instantaneous demand. If demand exceeds supply for any reason, part or all of the system can be under-powered. This is what happened on 8/14/2003: lines carrying power to portions of Ohio went down, causing local plants to overload and trip off-line and beginning the cascade of failures.When ever there is a power outage, a grid must be brought back up slowly.
This is why it is so important to prevent large outages. Small-scale load shedding is a vast improvement over any big failure. Systems which can react to an under-power situation fast enough to dump a few neighborhoods or plants before the generators or lines have to trip off will prevent outages from growing larger.Cutting off customers is a poor substitute for demand-side management. When there's a run on, say, toilet paper or gasoline, prices rise or suppliers run out. Latecomers delay their consumption and everyone has an incentive to decide how important it is to have the goods right now vs. later; there is no way to bring down the toilet-paper supply system. We have no such buffer like this for electricity; because of the false assumption that electricity will always be available when you flip the switch, too many people flipping the switch can cause everyone's power to go down. We need to address this sooner rather than later.
Although I hate calling a bug a "feature", the fact is that blackouts are often a testament to fault-detection which could otherwise overload a grid and cause more substantial problems that would take longer to resolve.
Fault detection is one thing. A faulty response to detection of a fault is another; if the system reacts to a shortage of generation capacity by cutting off generation rather than consumption, the protective systems act to decrease reliability. We may need measures such as mandatory utility control over air-conditioners (the major loads during summer demand peaks) in order to get a handle on this problem. -
Re:Scared?
This isn't news.
What do you mean, this isn't news? I've been waiting for someone to develop serious technology for a landing on Europa for quite some time now. Given that Europa is one big ocean and is the single most likely place in our solar system to find life (present planet excepted, of course) it's about time we thought about going there.
Now, the hippie spin on the word "radioactive" ... you're right. That's not news. People have been fearing the words "nuclear", "reaction", "radioactive", and "atomic" for many years now. Any damage that might be done to the surrounding area because of a failure would be absolutely insignificant on a planetary, or even regional, scale. Just because the media have taught us to fear and hate anything with the word "nuclear" in it is no reason not to trust the technology.
NASA has been using Radioisotope Thermoelectric Generators (RTGs) for decades on planetary probes and manned missions. The basic premise is this: a container holds some radioactive heavy metal, such as plutonium. Because the metal is decaying, it generates a bunch of heat. That heat is used with thermoelectric generators to create electricity, and the leftover heat (since the reaction is not not that efficient) is used in other ways, like keeping the astronauts warm. But here's the kicker: an RTG has never, ever failed on a space mission. Not once. It's been flown hundreds of times. (Missions using RTGs have failed, but the RTGs themselves performed flawlessly every time.) Just because it's "nuclear" doesn't mean it's Chernobyl. -
Re:If ya really wanna scare yourself...This issue has been extensively analyzed by years of DOE and NREL projects on bioethanol and other biofuels. Since bioethanol is produced from cellulosic feedstock, much of which can be cultivated in lands that aren't really arable for grains and other food crops, there isn't necessarily much competition. Additionally, there are lots of substantial sources of waste cellulose available that can be built into the production pipeline at a scaled up bioethanol plant. Like I said, don't listen to me, listen to the Department of Energy.
I don't deny that it's possible for crop prices to fluctuate, but generally I'd say that food prices are more stable in first world countries than gas prices. And the kinds of crops you are thinking of are mostly premium fruits and vegetables which are substantially more weather sensitive that what we are talking about here. Weeds, grasses and other low production cost cellulose sources can grow pretty much anywhere, barring serious dryness or "dustbowl" phenomena. -
Re:the problem with bioethanol...
Sorry, that's not bioethanol. You are talking about traditional corn ethanol, which is produced from a high production cost feedstock, corn. Bioethanol usually refers to ethanol produced from cellulosic feedstocks (and that's the sense I meant it in), which is broken down to glucose by preprocessing (acid hydrolysis, enzymatic hydrolysis or one of several other methods) prior to fermentation. The major difference is that cellulose is relatively cheap and plentiful, available from many sources, including sources that are normally considered waste from other industrial processes. I've posted a lot more detail on this before, but I encourage you to read more at the DOE OTT site.
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Re:Unrelated Question
Actually, you can bet that when NASA launches a rover designed to have a significantly longer lifespan, say, in 2009, there won't be solar panels on it to need cleaning.
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Organizing a team
Keep in mind that if you do want to participate in Science Olympiad, you will need a team of about 15 students (and 2 alternates, if you'd like) who are dedicated to their tasks. You can't win Science Olympiad if you're lazy, even if you're talented. It takes a lot of time, and considering that most regional competitions will be taking place within the next several weeks, you may find that there is not enough time to organize a team and prepare your events. Many events don't require thorough preparation, but several of them do.
Check with your regional coordinator to see if you will be allowed to take a partial team (last year my school took a team of 7 students and participated in only 14 of 23 events). It could still be fun to show up and only participate in some events, even if you just want to see if you're interested in next year's competition.
Other science-related high school competitions include the JETS TEAMS Engineering Competition and the National Science Bowl, which is more of a trivia competition. Unfortunately, it is too late to register for or participate in either of these events this year (most Science Bowl regional events are in February, with the Nationals in early May). -
Re:Thermodynamics is the half you don't know
I guess you thought it was a pissing match.
Brainstorm turns into brain-fart as soon as it leaves the bounds of reality.
This is one of my pet peeves. Too many people have no concept of what's actually possible within the laws of physics, and this ignorance of (or refusal to face) reality extends to their planning and even politics. Guess what happens when you plan on something that's impossible to achieve, or support a political platform which demands it? It can get very, very ugly.
Less visibly ugly but perhaps more damaging in the long run is the amount of thought wasted thinking about and communicating impossible or otherwise useless schemes. Ponder the number of real problems in the world and the amount of mental and physical effort wasted due to faulty understandings of what has to be done to solve them. Such waste can devastate entire societies. Native Americans conducted elaborate ceremonies to bring about the return of the buffalo, and look how far it got them. For more recent examples, see the pyramid schemes which bankrupted many people in the former Soviet Republics.
For one, there is no actual need for greater than 95% purity for fuel alcohol.
Only if you aren't planning on blending it with gasoline. If you are, you have to remove almost all the water or the mix will separate into an emulsion of distinct phases. Emulsified fuel was a serious problem for the designers of flex-fuel vehicles when I last followed that stuff, and I doubt it has become all that much easier since.
That brings us to more like 13.7%.
Reality check: a Carnot-cycle engine operating at ~1000 F (1460 R) high-side temperature and ~40 F (500 R) low-side temperature would have a theoretical efficiency of 960/1460=66%. In reality, a steam turbine operating around those parameters for the superheater temperature and the condenser temperature is about 33% efficient. Mechanical losses come off your net rather than your gross, so your 13.7% probably falls to the region of 2-3% if you're lucky.
If you could spend the same amount on hardware to get 33% or 3%, what would you spend it on?
It's not great, but it does represent recovered WASTE HEAT.
You can recover metal from aluminized gum wrappers, but it's not worth it. There are better ways to squeeze more out of the heat being used to run the stills, starting with integrating them with powerplants which are already dumping waste heat at nearly the necessary temperature anyway (and burning domestically-produced fuel to do it). Buying that steam would be a lot cheaper and vastly more efficient than buying natural gas; if the efficiency of the plant is reduced from 33% to 32% by the higher turbine-outlet pressure, you are talking about an increase of 323 BTU/KWH in the plant's heat rate. At 60% heat rejection out the turbine (a guess, assuming 8% up the stack) you would get your 33,000 BTU of steam for the distillery for a mere 1667 BTU in extra fuel. (My calculation: at 60% rejection as turbine exhaust steam, the 33,000 BTU of steam requires 55,000 BTU of fuel to produce it and the 32% efficient plant makes 17,600 BTU of electricity in the bargain. At 33% efficiency, the same amount of electricity requires 53,333 BTU of fuel.)
Historical heat rates for US electric powerplants are here.
Talk to an 8th grade science teacher (where I learned it decades ago). Or better yet, just heat some plant matter until it smolders. That 'smoke' is the mixture of tar and methanol, ready to burn at the slightest provocation.
I know it's flammable, I'm questioning your claims about composition and "mild heating". Anything that isn't methanol is a tar? What happens to the nitrogen, does it become nitrate, ammonia or something else? What kinds of temperatures do I need, and under wha
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Re:(TA)RDIS
Yes, we could. Write your congressman and say you want future Mars lander and rover missions to have more ground systems funding and to fend off the eco-wackos and install RTGs on them.
And by the way, we could put together another MER mission for about 200 million per rover now, since a big chunk of theat 800 million was R&D for the two we have.
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Re:Read the fine print
Where do you get the figure of 100 gallons of diesel fuel to produce 75 gallons of biodiesel? Or did you mean ethanol?
We had some figures earlier from a farmer that indicated it took around 3-10 gallons of (presumably) diesel to plant, fertilize, and harvest 1 acre of corn, yielding about 125-150 bushels of corn; each bushel yields about 2.5 gallons of ethanol, or a bit over 300 gallons/acre. The "tractor" portion of the energy equation is clearly not 100 gallons of diesel to produce 75 gallons of ethanol.
That same acre of corn can yield around 30 gallons of biodiesel, even without high-oil-yield corn (around 4% by weight). There's some energy cost to producing that as well, but again, the cost for planting and harvesting it is clearly not a huge percentage of the yield.
Even transporting the harvest is not that big a deal. A 10-ton truck will be carrying around 425 bushels, I believe (which can yield about 1000 gallons of ethanol and 100 gallons of biodiesel. How much diesel does it take to travel a few hundred miles in such a truck?
For some real numbers, check this 2002 U.S. Department of Agriculture study, it goes into great detail on methodology, assumptions, etc, and includes such things as the energy cost of producing fertilizer. For biodiesel, see An Overview of Biodiesel and Petroleum Diesel Life Cycles.
BTW, a big problem with some of the earlier analyses of how much energy it takes to produce ethanol are that they assume you need to vaporize a large quantity of water/alcohol in the distilling process and that you can't recover any of that energy. You can, of course, recover much of that energy, using the steam to pre-heat the incoming stock. That's not even looking at other possibilities, such as using solar power for heating (with much higher efficiency, when compared to using sunlight to either directly produce electricity and use that for heating, or grow corn and extract energy from that).
What we really need, of course, is an organism that takes sunlight and directly produces ethanol (or methanol, or methane, or whaever) from water and CO2 from the air. Run that through a solar still and you'd have a very effective transformation of sunlight into stored energy.
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Cellulase
The real key to biofuels would be the ability to use cellulose as the feedstock instead of just simply sugars.
Currently there is work going on to reduce the cost of using cellulase enzymes in the bioethanol process. Currently, cellulase-based bioethanol requires 30-50 cents of cellulase per gallon. To be economically competitive with sugar processes, the price has to be brought down to 5 cents per gallon.
At that point, bioethanol production could use the entire plant, including a large amount of plant waste that is simply thrown away today. -
Re:Making ethanol uses fossil fuels
As taken from here.
Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starch crops that have been converted into simple sugars. Feedstocks for this fuel include corn, barley, and wheat. Ethanol can also be produced from "cellulosic biomass" such as trees and grasses and is called bioethanol.
Yes it takes a lot of energy to make - a lot of solar energy and water in a method commonly known as 'growing'. -
Re:How to make the Ethanol
Well, no doubt fossil fuels are used somewhere along the lines, but this makes it sound pretty simple and mostly biological.
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Re:I'm curious...
As others have pointed out, there's nothing precluding a nuclear powered ramjet. Such an engine was actually built in the 1950's when they believed that radioactive exhaust was a bonus in an atmospheric missile. Obviously, something so dirty would never be a viable choice for non-warfare technologies. But using a more modern design like GCNR, the air could be heated without the air and fissionable materials coming in contact. Most gasses in the atmosphere can't be made radioactive by fission, so that's not a major concern.
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Re:Aerogel Facts and a Picture
It's interesting that Aerogel is always mentioned as being the insulator on the mars Sojourner Rover (and current mars rovers) but it's almost never mentioned that the heat source inside the insulated electronics boxes is not merely waste resistive heating from the electronic components themselves, but from Plutonium Radioisotope Heater Units of a couple ounces each. Maybe it's a good thing they're kept low profile, the clueless luddites would have a field day.
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Re:No, we don't!
Antrartica holds no strategic importance
The Department of Energy (more precisely, the Energy Information Administration) wouldn't agree with you. Their fact sheet says: "scientists discovered large deposits of natural resources such as coal, natural gas and offshore oil reserves in the early 1980s". -
Re:No, we don't!
Antrartica holds no strategic importance
The Department of Energy (more precisely, the Energy Information Administration) wouldn't agree with you. Their fact sheet says: "scientists discovered large deposits of natural resources such as coal, natural gas and offshore oil reserves in the early 1980s". -
Re:Yeah But We WON
We became his sworn enemy only when he invaded Kuwait and we realized that oil would be far cheaper in the hands of people we saved from invasion.
Ok- he tried to illegally expand his borders, and we kicked is ass back out. Even if we did just do it for oil, it was the right thing to do. And do you realize that we only get about 2% of our oil imports from Kuwait, right? If the was was just about oil, we would have probably gone after Canada or Mexico or Saudi Arabia instead.
Before or after we invaded Iraq? Nobody had any proof to this speculation before we invaded
President Clinton knew about Iraq's terrorist links. According to this recently leaked memo, the CIA has been tracking an al qaeda/Iraq link for over 10 years.
Where exactly are these again?
If Saddam had complied with the UN, we would know now, wouldn't we...
A capitalistic Iraq will allow those who participated in the invasion to profit immensely from transforming the middle east into a "western" country.
The Iraqis themselves are very optimistic about their future after Saddam. Why aren't you?
African nations in which we can lord impossible debts over their heads and force them into low wage labor.
Yeah- lets blame the US for everything. Many African nations are struggling with poverty- must be our fault. Theres no other explanation.
North Korea did react by announcing their intentions to blow up South Korea and Japan
North Korea's actions have just confirmed why we have regarded them as a terrorist supporting rouge nation for years now.
BUT, you had the possibility of owning one. So, I had to shoot you.
If you had seen me shoot people in the past with a gun, and you had no evidence that I had got rid of my gun, then yes, you should shoot me if I threaten to kill you. That is the smart thing to do. We are not suicidal, after all. -
Re:Why is this About US Opposing French Site ?
Last time I checked, Canada, Russia and China preferred the Japanese site.
When did you check? Canada is not even part of the ITER project anymore!
Some facts :
The actual members are The two proposed sites are Cadarache (EU) and Rokkasho-mura (Japan).
The main advantages of the Cadarache site are the climate and life conditions (most scientists would prefer the sun of the French Riviera to the snow of northern Japan) and the surrounding existing scientific institutions (Cadarache is already home to some France's fusion programs including the record-breaking 'Tore Supra' tokamak).
The main advantage of the Rokkasho-mura site is the proximity to the sea (very handy for collecting the parts manufactured by each member).
As stated in the BBC article EU, Russia and China support the Cadarache site (52%) when Japan and the US support Rokkasho-mura (38%). South-Korea initially supported the japanese site, but according to some news agencies, they are now open to change their views to avoid a deadlock.
Those were the facts.
Now for the rumors: the BBC states "The US has been against the French option because of France's opposition to the US-led invasion of Iraq." (my emphasis)
Such a feeling dates back to the choice of the EU site in may 2003 : the two bidders to be the european proposed site were Cadarache and Vandellos in Spain. As stated in this article in _Nature_, Spencer Abraham, the US energy secretary, publicly gave his support to Spain against France eventhough the choice was a matter for the EU. Cadarache was eventualy chosen unanimously by the european union member states. The US now supporting Japan (again against the technical merits of the two sites) is widely seen in Europe as a politically-grounded "anywhere but in France" stance.
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EM from nukes
To the list of complaints above I would also add that it seems unlikely that people capable of building faster-than-light spacecraft wouldn't know how to make radios that transmitted a clear signal. The amount of break-up and interference in those radio transmissions was ridiculous. And it didn't seem to make it difficult for the characters to understand each other, it just made it tougher for the viewer to hear what they were saying.
It is probably worth pointing out that many of these transmissions are to/from planets that have just had tens or hundreds of nuclear weapons detonated on them. Nukes put out a lot of of EM noise on their own, and even more if they are high enough to couple to the ionosphere. If I was a Cylon, I'd certainly make sure to include a few high-altitude nukes to help cut communications. -
Re:IEEE
It is surprisingly hard to find any census data on China (probably for obvious reasons). The data I could find is from over a decade ago. At that time (1986) over 60% of the population fell into the "peasant" category. Even if that number is only 50% now, that is still 600 million peasants who certainly aren't really in the market for wireless access points. Even a majority of those who are "non-peasants" probably aren't doing well enough to squander money on a WAP considering GDP per capita was only $467 in 1997.
I would guess less then 10% of the population of china could realistically be considered a "market" for electronic goods. That is a non-trivial 120 million people, but it certainly does not dwarf the combined western markets. -
DARPA redeemed
At the end of the article was some interesting information:
The research is sponsored by the Defense Advanced Research Projects Agency and the U.S. Department of Energy.
Perhaps this will help DARPA regain some of its cachet after the embarassingly stupid gaffe by Terror Bookie John Poindexter. Got to take the bad with the good, I guess... it's nice to be reminded that the Internet isn't all DARPA ever helped get off the ground.