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'Educated' opinions on climate change 41

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csd72

csd72

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May 4, 2006
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As engineers we are educated in physics and chemistry and should have a reasonable idea on what really effects the energy consumption that causes climate change. I am looking for peoples opinions on what suggestions have been good ideas to reduce your individual impact. Alternatively what suggestions have you heard that are utter nonsense.

It would be good to hear comments from engineers on this matter.
 
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Wow, matlab programmers read Douglas Adams.

I know I'm shocked;-)

KENAT, probably the least qualified checker you'll ever meet...
 
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In case you don't follow Hitchhikers guide in the book, the answer to the ultimate question of life the universe and everything is 42.

That is the humor in the matlab answer..

"Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?" Oddball, "Kelly's Heros" 1970

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.




 
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now you've gone and spoilt it sms.

Simple tip with regard to the OP.

Don't do a lot of cooking baking etc in the house when you have the air running.

I say this having spent all afternoon making my(in)famous chicken parcels which involves stove top and oven. All this in the middle of the Mojave desert with an external temp over 100F and a touch of humidity so the evaporative cooler isn't working well. We don't have central air.

What was I thinking, oh I remember now, the wife wanted them!

KENAT, probably the least qualified checker you'll ever meet...
 
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Since the thread has gone completely HHGTTG, here's my workings:

sum *

is syntactically identical to

sum('*')

or

sum('*')

and '*' is identical to [42]

However, I still have an inkling that that 42 being the ASCII code for * is no coincidence.
 
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KENAT,

maybe douglas Adams used matlab!

Somptingguy,

maybe this is the reason why the ASCE code was chosen as 42.

csd
 
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Eveyone knows who'll correct the problems. The earth natural cycles, economic pressures on the economies, and not hair burning, window jumping, flag wavers.

Is there any data that chngeing freons did anything other than making CF12 the largest smuggled material (even bigger than cocaine and herion). Acid rain, never really happened like predicted. Smog, still around, we changed out our equipment based on economic advances more than addition of catalytic converters.
 
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dcasto,

acid rain is real ... check the ph level (and the fish stocks) is canadian lakes. now if people were hyped into believing that acid rain would melt their cloths and burn their skin, well i have some "land" in florida i wouldn't mind selling
 
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Re Acid rain, didn't the Norweigans have a big problem with it due to the polution from the UK blowing their way. Swathes of dead forest, dead lakes etc. Or was the evidence that they were linked not sufficiently compelling for you dcasto?

(seems I was remembering the dead forest bit wrong)

Likewise I've seen numerous articles indicating the 'ozone hole' is shrinking but again perhaps these didn't meet your criteria.


Admittedly I don't think either site is peer reviewed etc but I didn't want to spend a bunch of time looking.

KENAT, probably the least qualified checker you'll ever meet...
 
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maybe dcasto was right about the ozone hole ... from kenat's link, the hole looks much the same size in '06 as it was in '92 (ok, numerically it's larger but how significant ?), tho' maybe the denisty is lower.

but i found this piece interesting ...
"The stability of the stratospheric polar vortex structure, which kept it generally centered over the South Pole, and the very persistent, anomalously cold temperatures in the presence of halogen levels that remain at high levels (though no longer at their highest levels) were the prime contributors to the record setting depletion."
 
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Civilperson- yeah but where does the electricity come from to power that geo-exchange heat pump unit? Generally in many regions of North America, that electrical power comes from thermal generating plants burning coal or some other fossil fuel. Recall that on average, for every ten units of fuel burned at that thermal generating plant, less than 1 unit of electrical energy actually gets used at the terminal end where your computer is plugged in. It is, in fact, more environmentally friendly to use a high efficiency natural gas furnace or domestic boiler in your house than an electrically powered geo-exchange heat pump in many areas of the world, and North America, unless your electricity is locally generated by micro-hydro, wind, solar or some other non-fossil fuel source
 
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"Recall that on average, for every ten units of fuel burned at that thermal generating plant, less than 1 unit of electrical energy actually gets used at the terminal end"
I agree they can be pretty inefficient. About twice as much heat is rejected to the heat sink as is extracted by the turbine, which puts most steam plants in the ballpark of 30 - 35% efficient. Still that's a long way from 10% and I thought the downstream components had pretty high efficiencies. Do you have any reference for the 10% number?

"It is, in fact, more environmentally friendly to use a high efficiency natural gas furnace or domestic boiler in your house than an electrically powered geo-exchange heat pump in many areas of the world, and North America, unless your electricity is locally generated by micro-hydro, wind, solar or some other non-fossil fuel source"
Don't forget nuclear. It is still subject to the low efficiencies of the fossil plant, but no emissions.

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Electricpete- I have some references at work, but I was speaking generally, and mileage may vary, but there are at least another 10-15% losses via transmission and voltage conversions, as well as the end-use appliance efficiency. Googling energy utilization efficiencies and electrical transmission efficiencies may provide some sources. In Canada we have very long distance transmission lines compared to many areas of the States so transmission losses are greater.

Absolutely nuclear is a player, but it is so politicized, and the media has instilled such fear in the average person that it is a difficult energy source to utilize in North America. I'd rather see all the tar sands in Ft. McMurray extracted by a nice little Candu nuke plant (see how close Ft. McMurray is to Uranium City, Saskatchewan) rather than burning up about 1/3 of the natural gas supply in Canada to make steam and hot water to extract their bitumen.
 
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Electricpete: just Googled some info on the overall energy utilization efficiency of thermal power plants:

"Note also that we have confirmed that the net thermal efficiency of the coal burning electric power generating plants is just under 30%. Actually, there are many additional losses in getting that electricity to distant homes, and the net electricity actually received at our electrical outlets is only around 13% of the original energy in the fuel! Sad, huh? (most of that additional 17% of energy loss is due to the long high-tension electrical lines that carry the electricity the many miles from where a power plant is to where you are. Since those wires carry very high electrical currents, and they have unavoidable electrical resistance, there is an unavoidable power loss of I2R. Essentially, all those long power lines act much like the wires in your toaster do, to get hot and radiate away heat. Conventional design of such high-tension lines is such that they INTEND that only 90% of the electricity put in one end of a 60-mile long high-tension line actually comes out the other end, and all the rest goes into heating the atmosphere around the wires!)"

from this link:


Also here is a link to European average thermal plant to gross electricty output at the plant:


Generally it looks like the realistic average efficiency of a thermal electrcial plant is about 30-35% at the point the electricty hits the high tension lines, then start subtracting transmission and voltage conversion losses down to the 115 volts you use in your house, and the generally accepted figure is that about 10% to 15% of the energy burned at a thermal generating plant comes out your plug at home, and then you lose even more due to the inefficiencies of the appliances using the power.

Thats why I like to argue with the geo-exchange heat pump zealots about how much more "efficient" they are. It all has to be taken in context. Geo-exchange heat pumps used in an area with relatively "green" electricty from hydro or nuclear IS a good thing, but the geo and heat pump systems are actually causing more pollution in a coal fired thermal plant zone, compared to burning the fossil fuel at a higher, more efficient level at the terminal end (your house).
 
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Efficiency is a difficult one to call because it depends on what is included.
With the de-bundling of electric power generation and the creation of auto-producers (i.e. large scale users generating their own power and selling the surplus to the national grid) quite a few operations saw a major increase in efficiency because they were able to provide CHP (Combined heat and power) so a textile factory or paper mill, which uses large amounts of heat, steam and electricity suddenly becomes very much more efficient when it generates its own power and steam. surplus of heat and electricity are all available to the community.
In CHP, large diesel engines can prove very efficient indeed and economically sound since they can use the cheapest fuels.

JMW
 
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