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(can of worms alert) Globe hasn't warmed in the last 16 years 76

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KENAT - some big transportation companies are buying new CNG trucks as a priority. More local than long-haul due to limited refueling locations, but long-haul is starting to shift that way too.

You're right that NG is currently unsustainably cheap, it's likely to float around $4-$5 for a long time in the USA. There is a LOT of cheap gas available with current techniques, and profitable to drill at $4-$5.
 
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patprimmer said:
While El Nino/La Nina cycles obviously have a significant impact on specific areas of the Pacific, don't they simply move the earths heat around without any generation as such.
Click to expand...

If it only moved heat around laterally across the surface then you wouldn't expect a change in global average tempreature. But since ENSO also affects vertical ocean currents, which can temporarily alter total heat content within that sliver of area called the 'surface' (where global average temperature measurements are taken), you can get temperature fluctuations on a global scale even if total system heat content remains constant.
 
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TomDOT.
My daddy always said "the definition of 'easy' is 'someone else has to do it'" To call combined cycle "cheep and easy" is to fly in the face of the 30 projects that I know of that rejected it as not economic even with tax incentives. The one project where the economics "worked" was a demonstration project that the CEO said "alternatives be damned, we are going to find the real benefits of combined cycle by building one". He lost his job, but the plant was built and it was a model of thermodynamic efficiency and 30 years later the ROI is about where a conventional plant would have been at 13 years.

As to natural gas as a motor fuel, I've been on three trials of that as well and they have all failed miserably. The refueling options are very high risk of both personal injury and significant loss of product, the vehicle range per "tank" is inadequate, and all the versions I've seen have paid an unacceptable power penalty.

Coal is the most abundant energy supply on the planet. Using coal for stationary power just makes sense from any viewpoint with a rational basis. Environmentalists hate the use of coal more than they would hate stoking a fire with baby seals. This hatred is not based on reality, just on prejudice. There are many other threads on eng-tips.com where this unreasoned bias has been discussed, so I'm not going into it again here.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
 
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David,

How long ago were you looking at combined cycle NG plants? I'm thinking the "teething problems" are mostly worked out, as there are a fair number in operation here in Texas, and more are being built.

A couple of current projects:



I don't know about the Temple project, but LCRA has already been running a combined-cycle NG plant since 2001, so they're not going into this build blind.


I admit that I haven't driven a CNG vehicle. I do have perhaps 5,000 miles in propane vehicles. Even with propane, the fueling was less convenient than traditional liquid fuels. Still NBD, but different. Making sure I had refueling locations was more of a hassle than the refueling itself.
 
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Public transit doesn't actually reduce carbon emissions that much, if you actually do the energy budget. You still burn the coal, and then there's power transmission losses, and inefficiency of the trains, and the fact that the trains aren't always full, and getting to/from the trains, etc, etc. But it sure would reduce smog.

As a resident of Atlanta, I think we need to reduce emissions so I can breathe better and so my 1 year old son doesn't develop asthma from the crappy air quality. There's plenty of reasons to reduce emissions that have nothing to do with Global Warming. My fear with the environmentalist movement, is they've hitched their entire wagon to a GW crisis that doesn't exist, and when the science finally falls flat on it, the whole movement will suffer.



Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
 
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The last one I saw rejected in the design stage was May, 2012, (it was another Engineer's project that I saw after the decision was made) it started out as a gas turbine to generate power for the grid and then all the pumps and compressors within the plant would be steam. The final design had all the pumps and compressors running on individual natural gas engines or grid power. As I recall this conventional design had a ROI that was nearly three times the combined cycle ROI.

We keep trying to do one-size-fits-all projects and a Swiss Army Knife is rarely the best economics, it is just a series of good-enough compromises. I have never been involved in building a facility whose primary purpose is power generation. Maybe there is a part of that kind of project that combined cycle fits perfectly and results in stellar economics. For providing power to an energy-intensive process facility the square peg just doesn't fit in the round hole (the killer is usually the cost of the genset and boiler compared to the price you get for the electricity).

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
 
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"the whole movement will suffer" I must say "GOOD". I had occasion to read a number of e-NGO responses to a proposed EPA regulation and I became convinced that the e-NGO's involved (28 of the biggest) could not care less about the environment--their primary agenda is punishing industry. One of the EPA proposals that we were able to get removed from the regulation would have resulted in significantly more air pollution than current practices, made the e-NGO's so mad that they threatened suit to have the high-polluting technique added back into the regulation. These guy do not speak for any community that cares about preventing harm to the environment. If the e-NGO's are the voice of the "movement" then the movement needs to suffer badly.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
 
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Many NGOs certainly have a seriously warped agenda. Can't argue with that.

There needs to be a sensible middle ground somewhere. That's becoming harder and harder to find in today's political climate of choice-between-false-extremes.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
 
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beej87, I'd like to see any energy budget that shows that it's even CLOSE to as energy efficient to move people one to a car than on a train. The carbon efficiency of trains is definitely far higher, regardless of fuel choice for either vehicle. Electric rail offers vastly less rolling resistance and frontal area by far, as well as easy regenerative braking so the mass of the vehicle matters much less- it's a hands-down winner as a means to move people for the least energy. And on a smog generation basis, public transit wins by a huge margin. Buses? They're more than a little dodgier from an energy efficiency perspective- they don't win unless they're nearly full most of the time, or unless they're electric trolley busses.

Cars are faster, destination to destination, as long as the public purse keeps building and maintaining roads. They're also more convenient, again provided you're not stranded in gridlock that a train could help you to avoid.

Nobody- not individuals or businesses- is going to substantially change the way they consume energy until they have a significant economic driving force to do so. You can't run an energy system on subsidy, so it has to be at least as much stick as carrot to work. I favour carbon taxes rather than cap and trade because they're simpler and less likely to be defrauded or to make the parasitic "financial services class" any richer than they already are. I also favour carbon taxes because the environmental impact of a fossil fuel tends to increase with increasing ratio of carbon to hydrogen. Taxes need to go into dedicated funds rather than general revenue, so that the tax revenue helps fund the switchover to more energy-efficient alternatives. I don't like carbon sequestration- it's too energy consumptive- so I wouldn't give credit for it.

Massive change is needed. Cities built around the car need to densify rather than sprawl further over farmland. Huge investments in buildings, transit, power generation etc. need to be made. But there will be plenty of benefits which come along with kicking the fossil monkey off our backs. We won't eliminate fossil fuels use ever- but we will deter the purely wasteful portion of it if we ever get the political will to give it a serious try.

Is gas part of the transition? Definitely. It's finite but it's also hard to use for transport, so stationary uses make far more sense than wasting most of it in an attempt to convert it to liquid fuels or even crazier, hydrogen as a vehicle fuel. The same goes for woody biomass- dumb to make liquid fuels out of it, when it's a perfectly good solid fuel we've been using for millenia.
 
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Anybody watch last nights' Frontline (PBS) program on the change in public opinion on GW? I expected it to be pretty slanted, and wasn't disappointed:)

Regards,

Mike
 
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Zdas, I wasn't suggesting the typical 'stick an NG tank in the trunk' conversion of an ordinary vehicle.

My understanding is there are already millions of NG vehicles vehicles worldwide.

Interesting what you said about the safety etc. concerns of refueling, I will admit I was under the impression these had mostly been addressed.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​
 
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Moltenmetal, you're not considering losses at the power plant and losses in the grid, nor how much energy it takes to run empty trains around all day. In terms of CO2 released, they're actually quite similar, for a power grid that's mostly coal. I still prefer trains because there's less surface pollution.

The same sort of thing crops up when you look at electric cars on a true carbon budget. They're not zero carbon even if they burn no gas. Electricity has to come from somewhere, and in the US that's largely coal.

Again, I'm not a huge fan of the presumption that all or even most global warming is due to anthropogenic carbon. I think the hydrologic cycle and the changes in land cover over the past two hundred years play a huge part, and aren't being studied hardly at all. I sure would like less smog though.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
 
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I've seen studies, and gas power generation isen't as cheep as coal.

I've looked into turning down my thermostat, and my family had more colds and such, and the offset to higher doctor bills is turn the thermostst back up.

I looked into public transportation and the issue with colds and such as above poped up, because of waiting at bus stops, as well as walking to and from. And those buses are not electric, and we don't want those over head wires in our view of the sourounding area.
Don't get me wrong, I want to get out of my car, it just dosen't make economic since for me to do so.

I still think the whole AWG thing is a tax reason the goverment is trying to sell the public. Becasue if it waswen't a tax thing we would find alternitives to applying taxes.
 
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Guys, you need to look at recent data when talking about this stuff. US electric production is not "mostly coal." It hasn't been "mostly coal" for approaching a decade. The shift was slow at first, but has accelerated rapidly the past couple of years due at least in part to cheap NG.

For 2010, coal was 45% of electricity production.
For 2011, coal was 42% of electricity production.
For the first 6 months of 2012, coal was only 35% of electricity production.

 
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TomDOT,
I look at that data and see that the 2012 coal generating capacity is basically the same number as the 1999 coal generating capacity and read it as "it has become nearly impossible for a new coal generating plant to be built in this country so we will build natural gas plants regardless of the projected cost of natural gas, or we won't build at all". Mostly we don't build at all, and I expect that we are less than a decade away from a major electric-capacity crises. The statistics in this case clearly say that the percentage of power generated from coal-fired plants is a declining percentage of total U.S. power generation.

What is subject to interpretation is why? Natural gas fired plants take about 7-12 years from start of Engineering to on-line. 7 years ago natural gas was $12/MMBTU with every single projection (including a couple that I wrote) expecting over $20 by 2012. At the same time coal was about $1.60/MMBTU projected to go to about $3.90/MMBTU by 2012 (low SO2 coal was $2.55/MMBTU start of August, 2012). Why in the world would anyone start a new power plant in 2005 for first production in 2012 assuming a fuel price of $20/MMBTU? Two reasons: (1) there was simply no way to get a permit for a new coal-fired plant in 2005; and (2) fuel price is a passthru on your electric bill so the utilities don't care. On a level playing field there is no way the projects coming on line today would have been funded.

The current very low natural gas price has nearly nothing to do with the shift away from coal for power generation--no one thinks it is permanent. The acceleration you mention is just timing of projects coming on line from the time the EPA got extra stupid during the Clinton years.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
 
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[ul]
[li]i can see that coal is more than all other fossil fuels combined, plus nuclear[/li]
[li]petroleum has dropped off significantly and largely replaced by NG (environmental permitting issues plus cost)[/li]
[li]no new nukes recently due to the same permitting issues as stated previously[/li]
[li]hydroelectric has not been expanded, even though it is "renewable" again this is a permitting issue[/li]
[li]wind has increased dramatically, mostly because of tax breaks - but to be fair it is less than 5% of coal[/li]
[li]solar PV is remarkably insignificant, not sure why so much fuss about it being able to reduce global warming. I think it's only being pushed for for political reasons...[/li]
[/ul]
 
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Cranky.

I think it is pretty well proven that within reason cold temperatures do not cause colds. It's people huddling together in confined spaces when looking for warmth or whatever other reason that aids in the spread of airborne virus that causes the spread of colds.

Riding in a modern commercial aircraft results in high incidence of colds and they are warm.

I would suggest that riding in the actual bus is a much greater risk of catching cold rather than the walk in the fresh air going to the bus stop.

As to turning down the A/C in winter, wearing a light weight comfortable sweater would fix that so long as the thermostat was set not to low.

Regards
Pat
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One aspect to this issue that makes it hard to discuss is that the whole thing is a statistical study.
All the variables that are inputs are subject to random fluctuations and the outputs are subject to random
fluctuations. This makes the item brought up by the OP a complicated question. Is this 15 year segment proof
of anything??
But more importantly how can we have 'proof' when the experiment can only be done once. We have to settle down
to dealing with probabilities of occurrences weighted by their impact.
Any global temperature charts show what appears to us as chaotic up/down movements that we cannot as yet deterministically
model so we have to fall back on statistical models of these patterns. So is the 15 year lack of significant heating
significant??
We assume i think that the greenhouse gas warming model would be something like this.
T=T_nominal + T_greenhouse*K*CO2_concentration + V

V is a random chaotic component that is assumed unchanged by greenhouse gasses, if not then roll its effect into
the model itself.

The V random component has then always been there causing chaotic behavior in times prior to GHG injection.
So if one was to capture the essence of this random behavior and superimpose it onto the projected trend line
of warming would there be likely periods of 15-20 year flatness or even downturn. Without actually digging in
very deeply one could just slice a period of the temp chart from pre GHG era and try sticking onto the warming
trend to see what happens. From a casual inspection of the chart prior to GHG era it looks like there may well
be 15-20 year flat periods. Of course that creates the question of how long a flat period is necessary to start
indicating a flaw in the warming hypothesis. Statistical analysis of the pre GHG charts would be a good place to start.

Also I would like to hear ZDAS04 reply to BRAD1979 concerning the Earths temp as inferred by Stephan Boltzman law.
 
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2dye4,
This is the 8th or 9th iteration of this discussion. I've read through all of them a couple of times and have yet to find a single instance of a single person changing their hard-felt beliefs. Not one. Ever.

I read the Wikipedia article on the Stefan-Boltzmann Law. While Wiki is not my favorite source for technical information, it is often in the ballpark. I was OK with the article until I got to the part about the temperature of the earth that uses the "greenhouse effect" as a plug value to explain why the average temperature is 30C or so higher than the "Law" predicts. It really did read like a "multiply times zero and add the answer you want" kind of exercise. A more technical analysis would probably avoid that silliness, but I don't care enough to go find one. I don't know why it has to be a "greenhouse effect" and not a "shielding effect" (i.e. without the atmosphere a greater portion of the sun's energy would reach the earth and boil us all) which would say that more mass in the atmosphere would be cooling instead of heating. The data supports that foolishness as easily as it supports the greenhouse stuff.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
 
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