[OldSprocket]

I find this diagram useful to drive home how much energy the U.S. of A. gets from fossil fuels.

The whole 1.6 Meg report is available from http://eed.llnl.gov/flow/pdf/ucrl-tr-129990-02.pdf

[MikeB]

I love using this in my classroom. The energy "lost" (ie wasted) just shocks the hell out of students.

[Andy]

If that diagram does not illustrate the potential for efficiency gains (particularly combined heat and power), then nothing will. Distributed electricity production utilizing waste heat can chop the waste from the electricity section from 26 quads to possibly 10. Of course, large central generating facilities are not very compatible with combined heat and power.

Look at transportation as well. Look at the percentage waste, it is the highest of all the fuel uses. This can also be cut by more than half eventually if we decide to favour more collective transport, smaller vehicles and scale down the use of the ICEV (Internal combustion engine vehicle), scale down air transportation and favour more steel wheel on steel rail transportation.

[0mar]

$this->bbcode_second_pass_quote('Andy', 'I')f that diagram does not illustrate the potential for efficiency gains (particularly combined heat and power), then nothing will. Distributed electricity production utilizing waste heat can chop the waste from the electricity section from 26 quads to possibly 10. Of course, large central generating facilities are not very compatible with combined heat and power.

Look at transportation as well. Look at the percentage waste, it is the highest of all the fuel uses. This can also be cut by more than half eventually if we decide to favour more collective transport, smaller vehicles and scale down the use of the ICEV (Internal combustion engine vehicle), scale down air transportation and favour more steel wheel on steel rail transportation.

[Kingcoal]

OldSprocket, your post, with very little words, says it all. All Americans should have this chart burned into their foreheads.

Currently, we have no energy policy at all in the US. Most of the old energy policies such as fuel economy standards for cars have been gotten rid of, or frozen, by either Bush1 or Bush2. Between 1970 and 1990 we became about 50% more efficient in our use of hydrocarbons. We need to keep going and people have to be made aware of that.

[aahala]

Kiddos, please review the above chart.

There may be a pop quiz concerning it during the semester and you may

be required to recreate it as part of your final exam.

[Devil]

Here is a similar chart for the UK

http://www.dti.gov.uk/energy/inform/energyflowchart.pdf

I've done a spreadsheet to compare the two, but unfortunately I can't post it here. It's quite revealing!

[OldSprocket]

I knew different people would see different things.

I cannot tell you how much of the electrical waste is long transmission lines and how much is inherent. Electrical devices each take a few to several percent of the energy passing through. My own very small off-grid solar electric system is very inefficient. The PVs capture a small part of the energy falling on them, and most days the batteries are full so the electricity nowhere to go. (Unless I'm on the computer and listening to the stereo.)

Likewise, much of the transportation waste is heat and unburned fuel, but how much is start-and-stop driving and traffic jams.

Another point the diagram show me is that non-fossil electrical energy is such a small portion of the current energy diet. There is NO WAY to expand it to cover for all fossil fuels. The U.S. needs deeper change.

At least that's what I see.

[JayHMorrison]

$this->bbcode_second_pass_quote('OldSprocket', 'A')nother point the diagram show me is that non-fossil electrical energy is such a small portion of the current energy diet. There is NO WAY to expand it to cover for all fossil fuels. The U.S. needs deeper change.

[OldSprocket]

$this->bbcode_second_pass_quote('JayHMorrison', '')$this->bbcode_second_pass_quote('OldSprocket', 'A')nother point the diagram show me is that non-fossil electrical energy is such a small portion of the current energy diet. There is NO WAY to expand it to cover for all fossil fuels. The U.S. needs deeper change.

[JayHMorrison]

$this->bbcode_second_pass_quote('OldSprocket', '
')It may cover the non-fossil electrical component, but the electrical component is still a small part of the whole energy picture. I think many people are looking for non-fossil energy to power hydrogen cars, residential heat, and other uses where electricity has been a minor component. I still think there is NO WAY to cover our wasteful diet without fossil fuels.

As with all estimates, YMMV.

[OldSprocket]

$this->bbcode_second_pass_quote('JayHMorrison', 'T')he electrical component is not a "small" component of the whole energy picture. The electrical component appears to be about 60% of the picture.

[Frank]

The Vanadian-Redox battery could play a role in the transportation side of things. Used electrolyte can be pumped out and replaced by fresh electrolyte fairly rapidly.

http://www.ceic.unsw.edu.au/centers/vrb/

The way I see it, any and all efforts to improve efficiency should be encouraged by policy and implemented ASAP.

[JayHMorrison]

$this->bbcode_second_pass_quote('OldSprocket', '
')Are we looking at the same diagram?

The figures in the diagram at the start of this thread say electrical energy provides less than twenty percent of the energy used. Of the electricity generated, sixty-six percent comes from fossil fuels, or thirty-four percent from non-fossil. Multiply thirty-four percent by twenty percent and I end up with less than seven percent.

Less than seven percent.

Please forgive me if I was looking at the wrong diagram.

[Devil]

I don't understand what OS is trying to say. The total energy used to provide electricity is 38.44% of all the energy used. This is hardly negligible. Unfortunately, 68.85% of it is lost. This is a terrible state of affairs, because 9.11% is non-thermal and the average of transmission losses (not specifically shown in the diagram) is about 5.1%. This means that the efficiency of the thermal systems is execrable and certainly nothing to be proud about, about 24%.

As I mentioned earlier, I did a comparison with the UK figures. I'll summarise consumptions:

Category UK% US%
Res/comm 12.83 19.72
Indust 9.27 19.12
Non-fuel 8.71 5.94
Transport 14.50 26.67
Electric loss 14.97 26.46
Other losses 5.33 0.00 (!)
Exports 34.43 3.02

Most of the other losses in the UK are natural gas emissions (horribly GHG)

Note the additions are not exactly 100%, but this is because of rounding errors and similar.

[JayHMorrison]

Devil, are there any energy losses from nuclear besides the standard transmission losses?

[Devil]

Of course there are: nuclear is just as thermal as coal/oil/wood/NG, in that the heat generated is used to make steam that drives turbines. The problem is that many turbine designs are single stage, so that the steam coming out may still be at 150°C or even much higher. This necessitates cooling towers, immersed heat exchangers or domestic heating heat exchangers to cool the steam down to condense the ultra-pure water for re-use. This alone represents losses of about 50% of the input energy (the rest would be bad boiler design, with typically 25% of the heat generated going up the stack, rather than into making steam). In terms of pure financial economy, there is a trade-off between thermal efficiency and capital cost: a triple expansion turbine costs ~8 x the cost of a single-stage one for an increase of shaft power of about 25% and maintenance costs and times are higher, too.

[OldSprocket]

$this->bbcode_second_pass_quote('JayHMorrison', 'I') am projecting forward based on example of France (nuclear 70%), Denmark (Wind 20%) and Germany (Wind 8%). Those examples tell us that it is feasible to have our electric grid be almost 100% non-fossil fuel based.

[JayHMorrison]

$this->bbcode_second_pass_quote('OldSprocket', '
')My point is that trying to power every air conditioner, power lawnmower, and giant SUV is preposterous. Reducing the energy budget is far more practical than expanding non-fossil electrical generation by 15 times its current size.

I live with off-grid electricity. I cycle. I'm not sure that we disagree too much as long as you might agree that non-fossil is currently a small portion of U.S. energy and that slashing energy use is as important or more important than expanding non-fossil electrical generation by 15 times.

[Ludi]

$this->bbcode_second_pass_quote('', 'I') expect solar power to become competitive