RE: Is clean coal possible?

Collarspace Discussion Forums

Home Login Search

RE: Is clean coal possible?

View related threads: (in this forum | in all forums)

Logged in as: Guest

All Forums >> [Casual Banter] >> Off the Grid >> RE: Is clean coal possible?

Page: << < prev 1 [2]

Login

Message

<< Older Topic Newer Topic >>

RE: Is clean coal possible? - 5/28/2009 10:44:59 AM

DomKen

Posts: 19457
Joined: 7/4/2004
From: Chicago, IL
Status: offline

quote:

ORIGINAL: samboct

Hi Ken

I must admit, I don't understand why regenerative braking would add to the distance traveled on a charge- I'd figure that the constant velocity trip would use the least energy.

Regenerative braking recharges the battery rather than wasting that energy as heat in the brakes. I assume in absolute level travel it probably doesn't add to range however even in relatively flat Chicago I go down hills enough to significantly add to the cars range.

(in reply to samboct)

Post #: 21

RE: Is clean coal possible? - 5/28/2009 11:54:52 AM

samboct

Posts: 1817
Joined: 1/17/2007
Status: offline

Hi Ken

"I assume in absolute level travel it probably doesn't add to range however even in relatively flat Chicago I go down hills enough to significantly add to the cars range. "

Still don't get that one. In order to go down hill, you've got to go uphill- and that takes more energy. Since you're always going to lose on the transformation- traveling up and down hills for 30 miles is going to take more energy than driving in Iowa 30 miles. Only if you're going slower does it make sense that you'd use less energy. So if you do stop and go driving at an average of 10 mph, that might take less energy than driving say a constant 40 mph due to wind resistance.

Sam

(in reply to DomKen)

Post #: 22

RE: Is clean coal possible? - 5/28/2009 4:04:08 PM

DomKen

Posts: 19457
Joined: 7/4/2004
From: Chicago, IL
Status: offline

quote:

ORIGINAL: samboct

Hi Ken

"I assume in absolute level travel it probably doesn't add to range however even in relatively flat Chicago I go down hills enough to significantly add to the cars range. "

Still don't get that one. In order to go down hill, you've got to go uphill- and that takes more energy. Since you're always going to lose on the transformation- traveling up and down hills for 30 miles is going to take more energy than driving in Iowa 30 miles. Only if you're going slower does it make sense that you'd use less energy. So if you do stop and go driving at an average of 10 mph, that might take less energy than driving say a constant 40 mph due to wind resistance.

Sam

I know the 2ndLoT so I've got concerns but the Prius has an indicator for when the battery is being charged by the engine and when its in pure EV mode and I drive back and forth to work, about 30 miles mostly city driving, without ever leaving EV. The only time I really use the engine is on the interstate which I only use for long distance trips. I will note that the Prius has a very low drag coeffecient and uses low rolling resistance tires so I think the air resistance issues might be part of why I get a lot better results than the ones claimed on your source website.

(in reply to samboct)

Post #: 23

RE: Is clean coal possible? - 5/28/2009 4:19:12 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

The 'Supremacy' of Petroleum as 'Bubble'* Fuel

* 'Individual Powered Bubbles' * is my little term for any kind of (non-living, non-animal) 'motorized' or otherwise mechanically, chemically, or machine powered transport regardless of fuel source (petroleum / veggie oil derived liquid fuels, compressed natural gas, electricity, compressed air, & so on); most especially used in reference to 'bubbles' specifically designed to transport humans at the individual & small group stage, & most particularly applicable to the resulting cultural shifts that widespread adoption of this technology results in.

Good thing I have little interest in persuading & am mostly laying this all out for the 'awareness' of the issues; I leave it to the interested to do more research, if they're inclined. Thank you, Sam, for the opportunity to lay out & codify some of my thinking on these topics. lol . . . & I'm gonna lead with the 'weakest' of my arguments; for the sake of some kind of organization, & to spare the reader one gigantonormous posting I've broken these into smaller, somewhat more focused postings . . . . . .

I'm not terribly competent at accurately repeating all the details of the highly technical stuff I've read about the unique position petroleum holds (& not just for fueling powered bubble transport), but I've heard pretty consistently that all the alternatives for powering cars have, over all, significantly greater up-front & operational costs, & significantly less efficiency. (Electricity, direct solar PVC-covered electricals, hybrids, CNG/LNG & compressed air, & others.) Part of this is the efficiencies-of-scale problem -- as more get produced the costs of production should come down, all other factors being equal.

I'll take a swing at laying out the basic thinking on at least one argument about why petroleum is the superior bubble fuel, & without it bubble-transports will get more expensive & / or will have significant trade offs such as reduced power (not one I'd really miss, personally) & or reduced range . . . .

The generation of electricity out of, say NG or coal, has a systemic inefficiency from the indirect method of power generation -- typically because most electricity generation comes from steam turbines. 100% efficiency of energy conversion from a given mass is the theoretical limit; most actual energy production is way lower than that . . . . . . (Engineering student offspring wanted me to say that the real-world maximum is only about 20% efficiency of fuel-conversion-to-power, but I'm only gonna put it in here in this tentative manner.) Fusion, anti-matter, & some other theoreticals can approach the 100% efficiency level, but not if they're used to boil water & drive turbines; that indirect process automatically lops a big chunk of efficiency off.

We would also have to invent technology that would convert the raw energy to electricity; as far as I know only photovoltaics produce electrical current directly, one of the advantages of that type of solar. Conventional nukes also basically 'burn' their fuels to produce heat that is then used to boil water & turn turbines, thus drastically reducing the total electricity producable from the theoretical energy contained in the fuel. If we had technologies that directly turned the energy released by the splitting atoms into electricity, or even straight-across turned the heat into electricity, we'd be getting an improvement in efficiency.

So. One of the advantages of petroleum is that the power generation is in situ & is directly driving the vehicle to a greater degree than electricity that is generated in a centralized plant & then routed to an end user.

There are losses of efficiency every step of the way with electricity generation & transmission. If we upgrade our electricity transmission infrastructure we can reduce some of the inefficiencies of transmission, but not eliminate those. I'll fall back on a basic engineering principle for that: it's possible to reduce risk / error rates / inefficiency to near zero, but the closer to zero the greater the cost, with cost approaching infinity at roughly the rate the problem approaches the zero solution.

A similar line of reasoning underlines why it's more 'efficient' to heat & cook with NG than with electricity . . . . .

(in reply to samboct)

Post #: 24

RE: Is clean coal possible? - 5/28/2009 4:38:06 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

Supply & Demand

Actually I'm in agreement with pretty much everything you're saying, Sam, I just have stuff to add to your picture to get to mine. & if you're unpersuaded, that's okay by me. My interest is more in the 'making aware' than in the persuading, lol . . . . . .

First off, there's the reason I reference all of this as discussion about 'finite mineral fuels'. They are all finite, despite the holders of those resources lying thru their teeth about how much is left. For instance, all the talk about how there are centuries of coal left has as little evidentiary support as the arguments about how, even if there is this thing called 'peak oil', we won't have to worry about it for decades to come. (Much of such talk ignores how much of these resources we've burned thru at a pretty rapid rate over the last century or two.) Specific to the discussion of coal, check out:

How much coal is out there?

(& also keeping in mind that we have preferentially used the cleanest, 'purest', & easiest to obtain & use fuels, so those are the ones most depleted. The vast majority of what's left is the 'dirtiest' & hardest to get at or use fuels, ie, more expensive, too.)

& as we shift from one fuel source (namely petroleum) to others (coal, NG, uranium), we'll start using that coal, NG, & uranium at a faster rate, all other factors being constant. But the reality is that one giant factor will not stay constant, & promises to overwhelm any gains we get thru increases in efficiency. (Especially given how reluctant we have demonstrated ourselves to be in embracing reduced energy use thru improved efficiencies.) & that big factor's growth is the increase in the global percentage of persons using fuels in whatever ways for whatever reasons, but most especially the spread of what I reference as 'car culture' -- the ubiquitous American model of individual car owner-operatorship.

Over the next 20 to 50 years a bunch of people are moving along the wealth curve, who in 2000 were poor, & who will be 'reasonably middle class' by 2050. (Anywhere from a billion to 3 or 4 billion, depending on how we define the terms & how the spread of globalized industrialism & wealth shakes out. My money's on the larger number.) This is a movement that is mostly going on in the poorest (& most populous) parts of the world, cuz basically that's the only place such movement could happen. The law of diminishing returns pretty much says there ain't much room for wealth growth in the richest places; that the greatest rate of overall return is gonna be in the lowest cost places. The same 'ugly' logic that has driven employment to lower price countries with more 'employment bang' for the 'labor buck'.

The biggest immediate movement is the half a billion to a billion people who are gonna get into cars for the first time in their lives over the period of time 2000 to 2020 -- something on the order of a 50% to 100% increase in regular car owner & operatorship over that period, most of it occurring outside of the US. The competition for whatever energy is gonna push all those 'individual powered bubbles' is gonna have profound effects domestically, because of the relatively large influence that 'car culture' has on US society, but also on less nationally affiliated issues such as car design. Whatever the car of 2020, or 2050, will be, it will probably be relatively small as compares to the recent American ideal of 'carliness', lol, for instance . . . . . .

So, when your Prius (I ride a bike or walk, thanks, don't really own a car anymore, haven't in a long time) is competing for fuel with 2 billion other drivers (or 3 billion, or 4), I'm gonna hold onto my viewpoint that supply & demand are gonna clash in a way the equates to greater costs for the relatively scarce ergs, pretty much regardless of how those ergs are generated. After all, there are only so many ergs that can be gathered or generated on the planet with current methods. & there are 6.7 billion people. In 2000 only about a billion of them had regular access to an individual powered bubble. I'm betting that given current trends, something like 3 or 4 billion will have the wealth-werewithall to own or operate an individual powered bubble by 2050, out of a probable total population of somewhere in the neighborhood of 8 or 9 billion . . . . . .. & we're well on our way to having 1.5 or 2 billion in cars by 2020, a mere 11 years from now . . . .. .

(Incidentally, most of those 'new car people' are climbing into cars at a higher gasoline / diesel price point than we Americans are comfortable with, & thus I would expect those 'new car people' will probably feel comfortable competing for fuel at higher price points than we Americans are gonna be comfortable with . . . . . . )

I am gonna stand by the idea that when we get to the roughly 3/4 empty point on the planet's oil tanks, all the prices are gonna go up a blip. How much I don't know, tho' I'm hazarding a guess that that point occurs not less than 5 years from now but not more than 20 years from today -- feels like a +98% confidence interval to me, lol . . . . .

Since you brought up polymers as a lower-cost replacement material, I gotta point out that plastics are, essentially, 'gasoline poop', lol, ie, repurposed left-overs of the 'cracking' process, further processed into useful materials. When oil refining has diminished, there will probably be an impact on the availability of all the materials generated by cracking petroleum. We can crack vegetable oil similar to petroleum, use it as an industrial feedstock, & burn it in diesel engines, but we've already had a tiny taste of how limited that source ultimately is, & how volatile its effects can be on the agricultural markets. 'Expensive plastic' actually sounds to me like a good thing, since so much manufactured plastic forms a significant chunk of our landfills.

There's a similar argument to be made to the 'finite mineral fuels' scarcity & depletion arguments about quite a few of the other mineral inputs needed by industry. One way I look at this is that, when it was a mere half a billion or billion people who lived relatively 'high consuming lives', there were plenty of materials. But, to my eyes, there clearly are serious resource limitations if 3, 4, 5, 6, or more billion people are participating in 'high consuming lifestyles' . . . .. . Tungsten, zinc, copper, bauxite (aluminum ore), & so on are finite resources here on Earth (the planet came equipped with only so much to begin with, & only so much of that is ever gonna be accessible to us no matter how fancy our tech gets . ... . . ) Because of these constraints I have serious doubts about whether we actually ever will be able to put 5 or 6 billion people into cars (circa 2050, out of a total popn. of 8 or 9 billion) . . . .

The super-simple summation of the above? Supply & demand. Demand is essentially an exponential curve & supply a much much flatter one . . . . . .

(in reply to DemonKia)

Post #: 25

RE: Is clean coal possible? - 5/28/2009 4:42:49 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

Less Relevant Thoughts on The Fostering of Tech Innovation

I'm actually rather rah-rah about technology & the possibilities to which humanity is heir, but I balance it with a healthy pessimism informed by how hesitant humans are to actually move briskly into the future. My observation is that it often looks a lot more like foot-dragging-our-way-into-the-future, frequently accompanied by a great deal of whining & crying & screaming & carrying on, lol . . . . . . .

I note, for instance, that one of the 'best' use of photovoltaics is for the environment they were originally engineered for -- space. The R&D is old skool on putting up arrays of photovoltaics in orbit around the planet -- solar satellite farms, so to speak. 24/7 near 100% efficiency for what they are capable of, condensing & beaming the resultant energy to earth on microwave or some such. Relatively dirt cheap, some environmental impacts but 'reasonably clean'. (I'd take it over nukes any day of the week, for instance -- I don't like current nukes mostly for our irresolute dealings with its after-products. The economics of adequately dealing with nuclear waste are an excellent example of our desire to low-ball costs in the immediate moment & ignore the inevitable long-term costs, & not structure pricing adequately.) But do you hear the crickets chirping on that solution? Cuz I do . . . . . A deafening silence, lol . . . .

lol . . . . . I keep going back to this story I heard -- lol, it'll probably turn out to be a hoax, but I didn't turn it up on Snopes, so *shrugs* . . . . That 'canned' food, the tin of food, was an invention of the early 19th century, but that it was several decades before the 'can opener' was invented. lol . . . . I picture all these hungry, slightly puzzled people armed with hammers & rocks, chisels & belt knives, finally getting the food out, but somewhat messily, at least at first . . . . . . lol

Yeah, 'technologists' will probably figure something out sooner or later, it all depends on the definition of 'sooner or later', lol . .. .. . I've been hearing 'just another decade or two' about commercially useful fusion for the 30 plus years I've been paying attention to the topic, & it's not looking a mite better now than then.

*long deep sigh* I have this completely unrelated (to this thread) rant about how science is, at its core, a creative pursuit, & as such has as much or more in common with art, another major creative outlet. That the things which cultivate the artist have applicability to the scientist. & those which can act antithetically to the artistic sensibility can also stultify the scientifically-expressive desire. & it's from that space that I say that I'd feel much more optimistic about our ability to produce technological wizzardry if we paradoxically were a lot less 'goal oriented' & 'profit driven' about the whole pursuit of technology thing. Especially if we coupled it to active, on the ground promotion & subsidizing of technical educations, above & beyond simply making 'higher education' ubiquitous for all adults. Oh. & the free exchange of ideas. (Ie, not 'locking knowledge away' behind copyright & profit-making concerns . . . . . . ) But, like I said, whole other thread there, lol . . . . . .

At the rate that things are going, all the relevant technologies will come along, eventually. But it probably won't be the rather exclusive province of US engineers designing them. *shrugs* I don't mind in the least, actually, I'm learning Chinese, lol, & I'm gonna add Hindi on next, lol . . . . . . . Those are the countries showing some serious dedication to the notion of technical educations for the masses, them & a chunk of Europe that takes pumping their masses thru higher ed far more seriously than the US. & we'll pay a price for the arrogance of thinking that we couldn't 'afford' to help people (in general) go to college & / or vo-tech schools . . . . . . Continuous education is gonna become the hallmark of a serious society that wants a place at the innovation table, all too soon.

(in reply to DemonKia)

Post #: 26

RE: Is clean coal possible? - 5/28/2009 4:44:57 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

Side Note on the Natural Gas Issue:

Yes, NG can be compressed, but requires fairly specialized facilities to both compress / uncompress, & to transport. It's analogous to how different refineries are equipped to handle different qualities of crude oil; most refineries can handle 'light sweet' crude (the easiest to refine stuff), but additional equipment & etc is required to deal with the heavier, sourer stuff, & so not all refineries can deal with all crudes. The NG issue is like that. There are issues about the exact composition of the NG, & the compressing station & decompressing station have to have reasonably 'matching' equipment. Thus, while NG is technically shippable over oceans the economic realities of the complexity of making that work make NG most 'price utilizable' when it's used on the same continent as it originates.

I'm not finding specific links about the technical issues -- which is why I'm not a researcher, lol, & pursue science-fiction rather than pure science . . . .. But here it's implicit in what's said:

"As probably most of TOD readers know, there's no such thing as a World Natural Gas Market, meaning that geographic regions unconnected with gas pipelines must be assessed separately."

&

"Options aren't many;...more LNG terminal ports and more LNG tankers; they all take time to come on line."

from: http://www.theoildrum.com/story/2006/11/27/61031/618

Basically this one boils out as economics rather than technical issues. If & when the price point customers are willing to pay is at the place where building & maintaining a 'local' CNG/LNG terminal port & transoceanic shipping makes commercially viable sense, then CNG gets shipped across seas. Otherwise, the overwhelmingly cheapest way to move NG is via pipelines.

LNG=Liquefied Natural Gas; CNG=Compressed Natural Gase . . . .. FYI

(in reply to DemonKia)

Post #: 27

RE: Is clean coal possible? - 5/28/2009 5:29:24 PM

samboct

Posts: 1817
Joined: 1/17/2007
Status: offline

Hi Ken

Well, perhaps not surprisingly, the makers of the auxiliary battery pack understated the available range with the existing pack....Gee, imagine my surprise. Since we both know the second law of thermo- I'll let you puzzle the regen braking stuff out.

Kia

OMG woman! You can type faster than I can read- and I'm not a slow reader.

In terms of the supremacy of petroleum as a fuel- well, the stuff has been around for a century- can't work all that badly. But the argument that electrics don't have some advantages misses the boat-

1) Pound for pound- watt for hp- an electric motor is far more compact and lighter than an equivalent IC engine. (Believe it or else- a lot of this stuff comes from the model airplane industry- which is rapidly throwing away its IC engines for electrics. The arguments before the advent of lithium batteries was that fuel had a far higher energy content then a battery- but in practice with the entire system- electrics now have better performance in most cases.) It's also far more efficient- it's pretty easy to get efficiency in the 85%+ category. So if you couple this with lithium batteries which have about 95+% energy return and good electronics which don't lose anything-energy into an electric car could easily hit 80+% efficiency.

Use a wind turbine to fuel the electric car- and it's renewable and the wind turbine is getting around 55-58% of the energy of the wind. Theoretical max is 60%, so this technology is mature. Use a superconductor to get the power from the Midwest to the Northeast- you'd lose maybe 5% if that. So basically we're pretty much there- there aren't massive gains in efficiency to be had.

You need to look up the Carnot cycle which is what determines the efficiency of a heat engine. (Electrics are not a heat engine and don't have to talk to the ghost of Sidi Carnot.) The equation is pretty simple 1- T1/T2. T1 is the temperature of the environment, T2 is the temperature of the process (use Kelvin). Hence cold weather and high heat increases efficiency. For an automotive engine- it's maybe 35%- and that doesn't take into account all the other losses such as transmissions, engine running friction etc. Nor does the petroleum industry include the energy requirements of the refining and transportation process.

If we transition to renewables sooner rather than later- the additional cars hitting the road in other countries (and I agree with you here) won't be that significant- especially if they use electrics rather than oil. I'll stand by my comments that liquid fuels will get more expensive- but that electrics will get cheaper in the future- and they're already close to competitive.

Sam

(in reply to DemonKia)

Post #: 28

RE: Is clean coal possible? - 5/28/2009 6:29:33 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

Just to be absolutely clear, most of my information about petroleum comes from critics of the industry.

I've been continuing to look for the stuff I was thinking about with regard to my (somewhat mockingly titled) 'Supremacy' of Petroleum posting. This put it pretty succinctly (particularly c & e):

from: http://www.theoildrum.com/node/3587

3. Why is petroleum more highly valued than other forms of energy?

There are many reasons:

a. Its abundance. Petroleum is the largest energy source for the United States, comprising 40% of our energy use. Coal and natural gas are each a little over half as big (23%). The new alternatives are tiny in comparison.

b. The fact that it is a liquid. Liquids are easy to transport and store. Imagine filling your fuel tank with coal!

c. Its high level of concentration. Those of us who have done cooking or counted calories know that oils have a lot more calories for the same volume than other foods. It is the same way with fuel. Gasoline has 115,000 Btu per gallon, or in terms we are more familiar with, 29,000 calories (of the type you eat in food –- actually kilocalories) per gallon. Ethanol, which is equivalent to alcohol in alcoholic beverages, has only two-thirds as many calories (that is, energy) per gallon.

d. Its low price. The reason oil has historically been inexpensive is that it takes a relatively small amount of resources to extract oil. In the early days of production, it took roughly the energy of one barrel of oil, plus a few other inputs (human labor and iron ore) to extract 100 barrels of oil. Even recently, it has taken as little as the equivalent as 15 barrels of oil (plus human labor and a few other inputs) to produce 100 barrels of oil.

e. Very favorable energy balance. This is just the flip side of Item d, oil's low price. If it only takes one barrel of oil to produce 100 barrels of oil, a small investment can create a huge amount of energy. Even if it takes 15 barrels of oil to produce 100 barrels of oil, there is still a very favorable return. This extra energy benefits society in many ways. It gives us the extra energy we need to build roads and malls and better our lifestyle.

f. Built Infrastructure. Nearly all of the cars, trucks, airplanes, and farm equipment currently in use were designed to burn oil products. While theoretically they could be replaced, this is a huge sunk cost. It would require technical innovation, a large investment of fuel and other resources, plus a timeframe of thirty or more years to convert to a new base.

g. Non-intermittent supply. At least historically, the supply of oil has been there, so that we could depend on it. We didn’t have to worry whether the wind was blowing, or a cloud was covering the sun.

quote:

ORIGINAL: samboct

In terms of the supremacy of petroleum as a fuel- well, the stuff has been around for a century- can't work all that badly.

...

Sam

(in reply to samboct)

Post #: 29

RE: Is clean coal possible? - 5/28/2009 6:51:48 PM

DemonKia

Posts: 5521
Joined: 10/13/2007
From: Chico, Nor-Cali
Status: offline

The first statement that I've left (highlighted) in your quote is not an argument I'm making; to my eyes it's a bit of a strawman, & thus I have to just sorta shrug & move on.

The overall disagreement we were having, I thought, was my assertion that we are transitioning from a time in which energy has been relatively cheap, & that at some not-too-distant point all energy sources are going to get more expensive.

I'm still standing by this from basically a two-pronged difference of vision from what I'm hearing in your posts: one is that with current tech development, electricity, as compared to petroleum, is inherently more expensive / less efficient as a fuel for transport. (& given the degree to which powered transport is important to our current US lifestyles, this is a much bigger issue than it seems . .. .) I got that your personal experience right now is that electricity is a relatively cheap way to power your car, but I'm not sure if you're understanding my point that if you were competing for that electricity with a billion (or 2 or 3) other electric car drivers in a world of dwindling electricity generating fuels, the cost of electricity is gonna go up.

The other prong to my argument is that all sources of energy generation are going to get more expensive in the not-too-distant future, given that both demand is probably gonna grow by hundreds of percents & that the fuels used to generate energy are in dwindling supply. & that one gets sharper when we pull back from thinking about just transportational uses of energy; all those billions of households that are gonna acquire air conditioning & refrigerators & computers & the other appurtenances of modern life . . . . . . .

Essentially, for me, it boils down to: sure, we can improve overall energy usage efficiency so that we're using, say, half as much energy per capita, but if the number of people using energy efficiently increases by two-fold, 3-fold, or more, the efficiency gains are swamped by the overall increase in demand.

For instance, to get us back to the coal topic, I've heard that if all the planet's energy needs were suddenly & magically converted to coal-generated electricity, the demand is such that we'd burn thru all the coal in a coupla decades. (Similar lines of reasoning extend to NG & to uranium.) From what I've read, it sounds to me like all the commercially extractable 'finite mineral fuels' will be gone by the end of this century, at best, & by 2050-ish, at worst. & those are calculations using fairly flat demand curves. If the demand curves instead continue with their more exponential shape, the picture gets uglier quite quickly.

quote:

ORIGINAL: samboct

But the argument that electrics don't have some advantages misses the boat-

1) Pound for pound- watt for hp- an electric motor is far more compact and lighter than an equivalent IC engine. (Believe it or else- a lot of this stuff comes from the model airplane industry- which is rapidly throwing away its IC engines for electrics. The arguments before the advent of lithium batteries was that fuel had a far higher energy content then a battery- but in practice with the entire system- electrics now have better performance in most cases.) It's also far more efficient- it's pretty easy to get efficiency in the 85%+ category. So if you couple this with lithium batteries which have about 95+% energy return and good electronics which don't lose anything-energy into an electric car could easily hit 80+% efficiency.

Use a wind turbine to fuel the electric car- and it's renewable and the wind turbine is getting around 55-58% of the energy of the wind. Theoretical max is 60%, so this technology is mature. Use a superconductor to get the power from the Midwest to the Northeast- you'd lose maybe 5% if that. So basically we're pretty much there- there aren't massive gains in efficiency to be had.

You need to look up the Carnot cycle which is what determines the efficiency of a heat engine. (Electrics are not a heat engine and don't have to talk to the ghost of Sidi Carnot.) The equation is pretty simple 1- T1/T2. T1 is the temperature of the environment, T2 is the temperature of the process (use Kelvin). Hence cold weather and high heat increases efficiency. For an automotive engine- it's maybe 35%- and that doesn't take into account all the other losses such as transmissions, engine running friction etc. Nor does the petroleum industry include the energy requirements of the refining and transportation process.

If we transition to renewables sooner rather than later- the additional cars hitting the road in other countries (and I agree with you here) won't be that significant- especially if they use electrics rather than oil. I'll stand by my comments that liquid fuels will get more expensive- but that electrics will get cheaper in the future- and they're already close to competitive.

Sam

(in reply to samboct)

Post #: 30

RE: Is clean coal possible? - 5/28/2009 7:30:44 PM

LookieNoNookie

Posts: 12216
Joined: 8/9/2008
Status: offline

FR:

Clean coal is not only absolutely possible...it's vital.

So long as it stays in the ground, right where it is....voila!

Clean coal.

(in reply to samboct)

Post #: 31

RE: Is clean coal possible? - 5/29/2009 6:03:09 AM

samboct

Posts: 1817
Joined: 1/17/2007
Status: offline

Kia

Simple problem. You're conflating available energy with convenience. There are only two sources of energy for the planet- the sun, and radionuclides that keep the core molten. Oil is just a bunch of organic compounds that have been cooked for a while.

We've got tons of energy- there's no lack of the stuff. Powering the entire planet with wind- might change some local wind patterns but overall- wouldn't put a dent in the total amount of energy there. Solar- good for a few billion years. Our entire energy needs would be met by capturing the solar energy that falls into a 100 km x 100 km sq. and I think that's with 20% efficiency of conversion. Geothermal- OK- this one can be a bit more finite- try and extract too much and you do cool the rock, but if done correctly- there's plenty of warmth in the ground. Hydro?- again, we're not running out anytime soon and refurbishing existing hydro plants to get more energy out of the falling water wouldn't be a bad idea. Current designs can hit 95% efficiency by the way.

So while fossil fuels are certainly a finite resource, in practical terms, there's plenty of total energy hitting the planet. Once we figure out how to transform it into either electricity or fuel- and we're doing pretty good with a bunch of technology, the costs will come down. Since the costs are already on par with fossil fuel technology- these costs will become lower. It's beginning to dawn on me that this is the great big secret of fossil fuel replacements- they'll be cheaper than the current technology, and then where will Exxon Mobil be?

The argument that energy costs will go up and there will be shortages is very similar to the argument that the depressing preacher- Thomas Malthus wrote about in terms of food production. His comment was that population grew faster than food production. Obviously, he's been wrong to date. You're making the same mistake he did- extrapolating out energy needs using existing technology. This is a common error among economists. They don't understand technology so they make gross and inaccurate assumptions that invalidate their models. But solving the energy problems of 10 years in the future means that we'll have 10 years of additional science/engineering to help. Now, mind you, the Bush administration has done its damnedest to emulate Mao's Great Leap Backward, but this country has a history of resilience, and our current pres. is not a moron. In short- there's no fundamental problem here- there's only a lack of political will and intelligent economics, and both of those may be getting rectified.

Sam

< Message edited by samboct -- 5/29/2009 6:07:17 AM >

(in reply to LookieNoNookie)

Post #: 32

RE: Is clean coal possible? - 5/29/2009 6:46:12 AM

DomKen

Posts: 19457
Joined: 7/4/2004
From: Chicago, IL
Status: offline

quote:

ORIGINAL: samboct
the depressing preacher- Thomas Malthus wrote about in terms of food production. His comment was that population grew faster than food production. Obviously, he's been wrong to date.

Malthus was right for all of history before about 1965. We will eventually exceed even Norman Borlaug's ability to keep Malthus at bay and he will be right again.

(in reply to samboct)

Post #: 33

RE: Is clean coal possible? - 5/29/2009 10:04:32 AM

samboct

Posts: 1817
Joined: 1/17/2007
Status: offline

Hi Ken

Have you been watching the rates of population growth lately? Seems to me that Malthus's basic axiom that there will always be population growth isn't doing so hot- look at the birth rates in Japan, Italy (and other parts of Europe) and the US amongst non-immigrants. I might argue that this declining birth rate is symptomatic of a sick society, but that's another thread and a different debate. But given that birth rates are declining in lots of countries with improved medical care etc and we're starting to transition away from fossil fuels- I think Malthus's dystopia is probably going to be held at bay for awhile longer.

Sam

(in reply to DomKen)

Post #: 34

RE: Is clean coal possible? - 5/29/2009 10:32:03 AM

DomKen

Posts: 19457
Joined: 7/4/2004
From: Chicago, IL
Status: offline

quote:

ORIGINAL: samboct

Hi Ken

Have you been watching the rates of population growth lately? Seems to me that Malthus's basic axiom that there will always be population growth isn't doing so hot- look at the birth rates in Japan, Italy (and other parts of Europe) and the US amongst non-immigrants. I might argue that this declining birth rate is symptomatic of a sick society, but that's another thread and a different debate. But given that birth rates are declining in lots of countries with improved medical care etc and we're starting to transition away from fossil fuels- I think Malthus's dystopia is probably going to be held at bay for awhile longer.

Sam

Who really cares about the birth rates in western Europe, the US or Japan? None of those nations are anywhere near their carrying capacity. India and China, roughly half of the worlds population, is where the action is and there is no indication of a significant drop in birthrates in India and China's population control strategy has been shown to be woefully inadequte. Right now starvation is not occuring in either nation only because of Borlaug's dwarf wheat and rice. However there is a practical limit to how much cereal can be grown even using those varieties and once that limit is exceeded we'll be right back to Malthus.

(in reply to samboct)

Post #: 35

RE: Is clean coal possible? - 5/29/2009 1:58:48 PM

samboct

Posts: 1817
Joined: 1/17/2007
Status: offline

Ken

It takes a bit for the drop in birth rate to show up- and as both India and China have a rapidly burgeoning middle class- I'll be we see a decrease in birth rate in a decade.

Sam

(in reply to DomKen)

Post #: 36

Page: << < prev 1 [2]

All Forums >> [Casual Banter] >> Off the Grid >> RE: Is clean coal possible?

Page: << < prev 1 [2]

Jump to:

New Messages	No New Messages
Hot Topic w/ New Messages	Hot Topic w/o New Messages
Locked w/ New Messages	Locked w/o New Messages

Post New Thread

Reply to Message

Post New Poll

Submit Vote

Delete My Own Post

Delete My Own Thread

Rate Posts

Collarchat.com © 2025

Terms of Service

0.094