| View previous topic :: View next topic |
| Author |
Message |
spot5050
Heavy Crude
![]()
Joined: Dec 07, 2004
Posts: 483
Location: Cheshire, England
|
 Posted: Mon Jun 20, 2005 5:46 pm Post subject: EROI calcs |
  |
|
Can anyone point me towards EROI calcs/stats for any of the following;
Solar panels
Nuclear
Wind farms
Tar sands
Oil shale
Geothermal
Hydroelectric
Tidal
...or any other "renewable" energy sources.
Just to clarify: I'm not after general info, I'm looking specifically for EROI info. I'm getting nowhere so far! Many thanks in advance. |
|
| Back to top |
|
 |
Wildwell
Fission
Joined: Feb 03, 2005
Posts: 2080
Location: UK
|
| Posted: Mon Jun 20, 2005 6:33 pm Post subject: |
|
|
http://www.eroei.com/eval/net_energy_list.html
Oil and gas (domestic wellhead)
-1940's
Discoveries > 100.0
- 1970's
Production 23.0, discoveries 8.0
Coal (mine mouth)
- 1950's
80.0
- 1970's
30.0
Oil shale 0.7 to 13.3
Coal liquefaction 0.5 to 8.2
Geopressured gas 1.0 to 5.0
Renewable
Ethanol (sugercane) 0.8 to 1.7
Ethanol (corn) 1.3
Ethanol (corn residues) 0.7 to 1.8
Methanol (wood) 2.6
Solar space heat (fossil backup)
Flat-plate collector
1.9
Concentrating collector
1.6
Electricity Production
Coal
U.S. average
9.0 (27.0)
Western surface coal
No scrubbers
6.0 (18.0)
Scrubbers
2.5 (7.5)
Hydropower 11.2 (33.6)
Nuclear (light-water reactor) 4.0 (12.0)
Solar
- Power satellite
2.0 (6.0)
-Power tower
4.2 (12.6)
-Photovoltaics
1.7 (5.1) to 10.0 (30.0)
Geothermal
-Liquid dominated
4.0 (12.0)
-Hot dry rock
1.9 (5.7) to 13.0 (39.0)
Table Notes: Estimates of energy return on investment (EROI) ratios for some existing and proposed fuel supply technologies. Numbers in parentheses for electricity generation include a quality factor based on a heat rate of 2646 kcal/kWh.
If you are a mathematician and would like to see some of the theory behind this, here is a PDF of a paper entitled: "Aggregation and the role of energy in the economy" by Cutler J. Cleveland, Robert K. Kaufmann, and David I. Stern. [download - 184kb]
Energy Yield Ratio List
from
Environmental Accounting, Emergy, and Decision Making
Howard T. Odum
(John Wiley, 1996)
[EDITOR'S NOTE: Odum has created the term "emergy". He explains it as:
Emergy (spelled with an "m") evaluates the work previously done to make a product or service. Emergy is a measure of energy used in the past and thus is different from a measure of energy now. The unit of emergy (past available energy use) is the emjoule to distinguish it from joules used for available energy remaining now. Scienceman describes emergy as energy memory (Odum, 4, 6, 10; Scienceman, 9, 10)*.
Richard Heinberg describes Odum's "emergy" as "embodied energy".]
ITEM ENERGY YIELD RATIO
Dependent Sources, No Emergy Yield
Farm windmill, 17 mph wind 0.03
Solar water heater 0.18
Solar voltaic cell electricity 0.41
Fuels, Yielding Net Emergy
Palm oil 1.06
Energy-intensive corn 1.10
Sugarcane alcohol 1.14
Lignite at mine 6.8
Natural gas, offshore 6.8
Oil Mideast purchase 8.4
Natural gas, onshore 10.3
Coal, Wyoming 10.5
Oil, Alaska 11.1
Rainforest wood, 100 years growth 12.0
Sources of Electric Power, Yielding Net Emergy
Ocean-thermal power plant 1.5
Wind electro-power 2-?
Coal-fired power plant 2.5
Rainforest wood power plant 3.6
Nuclear electricity 4.5
Hydroelectricity 10.0
Geothermal 13.0
Tidal electric, 25 ft. tidal range 15.0 |
|
| Back to top |
|
|
DriveElectric
Intermediate Crude
Joined: Mar 12, 2005
Posts: 639
|
| Posted: Mon Jun 20, 2005 7:23 pm Post subject: Re: EROI calcs |
|
|
| spot5050 wrote: |
Just to clarify: I'm not after general info, I'm looking specifically for EROI info. I'm getting nowhere so far! Many thanks in advance. |
You probably never will get anywhere with EROEI. It's usefulness as a measure of energy is questionable. Nobody really uses it because of the lack of relevance or standards involved. There are numerous discussions already posted where this issue has been debated with quite a lot of input from true experts. The general consensus is that it is useless to really make any meaningful decision based purely on EROEI. |
|
| Back to top |
|
|
spot5050
Heavy Crude
![]()
Joined: Dec 07, 2004
Posts: 483
Location: Cheshire, England
|
| Posted: Thu Jun 23, 2005 5:11 pm Post subject: |
|
|
| Wildwell wrote: | http://www.eroei.com/eval/net_energy_list.html
...
|
Thanks wildwell. I'll have a trawl through that lot.
| DriveElectric wrote: | | Arguing on the internet is like playing in the special olympics, even if you win you're still retarded. |
ROFL! I like it 
But how can you say this?...
| DriveElectric wrote: | | You probably never will get anywhere with EROEI. |
Eh?
| DriveElectric wrote: | It's usefulness as a measure of energy is questionable.
Nobody really uses it because of the lack of relevance or standards involved. |
So you are questioning the laws of physics. I wish you luck. |
|
| Back to top |
|
|
DriveElectric
Intermediate Crude
Joined: Mar 12, 2005
Posts: 639
|
| Posted: Thu Jun 23, 2005 6:33 pm Post subject: |
|
|
| spot5050 wrote: | | DriveElectric wrote: | It's usefulness as a measure of energy is questionable.
Nobody really uses it because of the lack of relevance or standards involved. |
So you are questioning the laws of physics. I wish you luck. |
Explain to me how EROEI is relevant to physics?
Also explain to me the standards for exactly how to calculate EROEI. We
have spent numerous threads on this topic and nobody has been able to defend EROEI as useful at all. If you can do otherwise, I will be impressed. |
|
| Back to top |
|
|
Dezakin
Light Sweet Crude
Joined: Feb 09, 2005
Posts: 1373
|
| Posted: Fri Jun 24, 2005 12:53 am Post subject: |
|
|
| Quote: | | Nuclear (light-water reactor) 4.0 (12.0) |
This gem here easily leads me to suspect the credibility of this particular site, given extremely conservative analysis puts 'EROEI' numbers for light water reactors in the 20s using old gasseous diffusion enrichment procedures. (1950's tech)
It has been discussed here:
http://www.peakoil.com/fortopic6750.html
with links to the study:
http://www.world-nuclear.org/info/inf11.htm |
|
| Back to top |
|
|
jato
Moderator
Joined: Aug 14, 2004
Posts: 2068
Location: San Diego, Ca.
|
| Posted: Fri Jun 24, 2005 1:33 am Post subject: |
|
|
| Quote: | | Explain to me how EROEI is relevant to physics? |
Let’s use the coal example:
Coal (mine mouth)
- 1950's
80.0
- 1970's
30.0
At what point does coal production stop?
EROEI of 1.5?
of 1?
(getting ridiculous now)
of 0.1?
of 0.001?
Even with solar powered/nuke powered electrical equipment coal will reach a point where it is useless to mine and use as a primary source of energy.
Obvious example: Why spend 10 times the electrical energy (or any other energy) moving whole mountains to get at a small seam of coal when you could use the original source of energy directly?
_________________
"Peak oil isn't more than an interesting industry factoid and doesn't have anything to do with the hysterics speculated on ad nauseum around here!" ReserveGrowthRulz |
|
| Back to top |
|
|
Doly
Expert
Joined: Dec 03, 2004
Posts: 4040
|
| Posted: Fri Jun 24, 2005 1:55 am Post subject: |
|
|
| The only source of energy I know that was abandoned because of diminishing returns is wood in Europe. Maybe somebody could calculate at what EROEI wood was abandoned. |
|
| Back to top |
|
|
JohnDenver
Light Sweet Crude
![]()
Joined: Aug 29, 2004
Posts: 1878
|
| Posted: Fri Jun 24, 2005 1:58 am Post subject: |
|
|
| Quote: | | Coal liquefaction 0.5 to 8.2 |
This is also suspicious. How do you get more energy out of coal liquefaction than you put in?
One of the problems with the work of Cleveland and Kaufman is their use of "quality" fudge factors in their EROEI formula:
"...where lambda[i,t] is the quality factor for fuel type i at time t and Eo and Ec are the thermal equivalents of energy outputs and energy inputs, respectively. We construct Divisia indices for energy inputs and outputs to account for energy quality in the numerator and denominator."
http://www.eroei.com/pdf/Aggregation_role_of_energy.pdf
"We define energy quality as the relative economic usefulness per heat equivalent unit of different fuels and electricity."
http://www.eroei.com/pdf/Aggregation_role_of_energy.pdf
Those lambdas should not be in there. EROEI is defined as joules out divided by joules in.
How were those numbers from eroei.com calculated? None of the people citing that source as evidence has any idea where they came from, or whether they can even be compared. All the original sources date from the 70s and early 80s, and they're all rotting in the stacks somewhere. Let's face it, nobody has any idea what those numbers mean. |
|
| Back to top |
|
|
jato
Moderator
Joined: Aug 14, 2004
Posts: 2068
Location: San Diego, Ca.
|
| Posted: Fri Jun 24, 2005 2:05 am Post subject: |
|
|
John you bring up a good point. A standard must be made in regards to calculation. However, EROEI is still a very important CONCEPT relevant to declining energy.
_________________
"Peak oil isn't more than an interesting industry factoid and doesn't have anything to do with the hysterics speculated on ad nauseum around here!" ReserveGrowthRulz |
|
| Back to top |
|
|
JohnDenver
Light Sweet Crude
![]()
Joined: Aug 29, 2004
Posts: 1878
|
| Posted: Fri Jun 24, 2005 2:05 am Post subject: |
|
|
| jato wrote: | | At what point does coal production stop? |
IMO, coal production will stop when we run out of coal. Coal will run out before the EROEI gets low enough to halt mining. |
|
| Back to top |
|
|
JohnDenver
Light Sweet Crude
![]()
Joined: Aug 29, 2004
Posts: 1878
|
| Posted: Fri Jun 24, 2005 2:12 am Post subject: |
|
|
| jato wrote: | | EROEI is still a very important CONCEPT relevant to declining energy. |
I agree. We need to understand it better. I know of two cases where a form of EROEI is useful in the real-world.
1) Determining whether there is a net energy return from fusion
2) Determining the point where a coal mining company should switch from strip mining (where the overburden is removed) to auger or underground mining (where the overburden isn't removed). |
|
| Back to top |
|
|
jato
Moderator
Joined: Aug 14, 2004
Posts: 2068
Location: San Diego, Ca.
|
| Posted: Fri Jun 24, 2005 2:14 am Post subject: |
|
|
| Quote: | | IMO, coal production will stop when we run out of coal. Coal will run out before the EROEI gets low enough to halt mining. |
I agree to the extent that "running out" of coal will be related to EROEI even if nobody does an EROEI calculation. We will never truly "run out" since there will always be some coal in the ground someplace. However, I understand exactly what you are saying.
_________________
"Peak oil isn't more than an interesting industry factoid and doesn't have anything to do with the hysterics speculated on ad nauseum around here!" ReserveGrowthRulz |
|
| Back to top |
|
|
spot5050
Heavy Crude
![]()
Joined: Dec 07, 2004
Posts: 483
Location: Cheshire, England
|
| Posted: Fri Jun 24, 2005 2:24 am Post subject: |
|
|
| DriveElectric wrote: | | spot5050 wrote: | | DriveElectric wrote: | It's usefulness as a measure of energy is questionable.
Nobody really uses it because of the lack of relevance or standards involved. |
So you are questioning the laws of physics. I wish you luck. |
Explain to me how EROEI is relevant to physics?
Also explain to me the standards for exactly how to calculate EROEI. We
have spent numerous threads on this topic and nobody has been able to defend EROEI as useful at all. If you can do otherwise, I will be impressed. |
I agree it has been 'discussed' many times, but it has never been discussed very well! The initial question is always poorly defined, people chip in with various OT points, they start arguing about whatever their particular beef is and loose sight if the initial question, if there ever really was one.
Take a step back for a moment. All I am saying is this;
Energy is quantifiable in various forms. Bearing in mind the first law of thermodynamics, it might be possible to calculate from first principles how much work a process uses compared to how much energy it releases.
If you would like to discuss this, I would be very happy to. But the question must be defined first. If the term 'EROEI' causes so much angst, then lets not use that term - lets just define a principle and give it a name afterwards. |
|
| Back to top |
|
|
DriveElectric
Intermediate Crude
Joined: Mar 12, 2005
Posts: 639
|
| Posted: Fri Jun 24, 2005 7:24 am Post subject: |
|
|
| Doly wrote: | | The only source of energy I know that was abandoned because of diminishing returns is wood in Europe. Maybe somebody could calculate at what EROEI wood was abandoned. |
I lived in Europe for a number of years. I can assure you that it is still being used as an energy source. Especially on cold nights at the lakehouse when I want to grill some kielbasa and keep warm. |
|
| Back to top |
|
|
|
News
Discussions
Resources
Members
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
