YOU!: Fix the US Energy Crisis

russ_watters

I don't see how such thought experiments are useful. The only part of it that comes anywhere close to realism is the 5-fold increase in nuclear power. Everything else is just daydreaming:

-Halving our energy usage is not an option - it isn't even desirable
-Completely eliminating coal hydrocarbon, and hydroelectric(!?) energy usage is not an option - it isn't even desirable.
-Solar power has no viability so it cannot be a part of an energy solution at this time
None of those have any potential:
-Tidal power is expensive and there isn't much of it available
-Geothermal energy is not available
-Biofuels are not available
-hydroelectricity is essentially fully utilized already
There is no realistic generation potential there. Heck, the energy usage of the average home isn't even that big a factor in the thought experiment. It is only something like 1/10th of our energy use. Most people use as much energy driving to and from work every day than their house uses during the day! (a gallon of gas is 45 kWh) If my poop smelled like cinnamon apple crisp, I could sell it as an air freshener! This just isn't reality.

gmax137

Well this may provide some perspective on the scale of the energy use, and as such it may be useful for people who are less quantitatively aware than most of the readers on this forum. But really, mixing various forms of energy use (e.g., direct combustion for home heating along with electrical power used for lighting, refrigeration & TVs) just leads to confusion. It misses the differences in efficiency etc. Read back thru this thread and others to see endless debates & misunderstandings due to this lack of specificity.

More important, mgb_phys is quite correct in pointing out the difference between average usage, and usage in the average home. Check into the amount used in office space, retail, and industrial facilities.

mheslep

That's more like it - no summing them altogether with the "plus"s used above.

mheslep

Mackay's 125kWh/d breaks down as follows (major parts):

• Car: 40kWh/d
• Jet travel: 30kWh/d
• Heating/Cooling: 37 kWh/d
• Food/fertilizer: 14 kWh/d
• plus misc.

Cars, heating/cooling could be improved, but as a whole there's no cutting this in half.
Also, the 125 figure doesn't include energy spent on creating imported goods (47kWh/d).

Astronuc

This might be of interest to some

Handbook of photovoltaic science and engineering By Antonio Luque, Steven Hegedus

http://www.amazon.com/gp/product/0471491969

Cutting energy consumption in half would seem to be a good thing. We could eliminate a lot of garbage by not producing so much junk in the first place.

russ_watters

Sure, so would money rain. But that doesn't make it realistic. Thermodynamics puts pretty hard limits on what efficiency gains can be had. There are some gains to be had with improved insulation, but modern homes are already pretty good. And they aren't the big energy users anyway: business are and they also have hard constraints on energy consumption (ventilation and equipment loads).

mheslep

There's also Jevon's Paradox to contend with

vanesch

I would like to "defend" MacKay's book (which is really, really worth the read): you can buy it, but it is also freely available for download at http://www.withouthotair.com

However, one should read it *completely*. MacKay is NOT proposing a specific energy plan, or he's not proposing *how* one is going to live "sustainably".
He's just writing a catalog of "numbers" which are guesstimates, and rough indications of tendencies en dependences, just to "get realistic" about renewables.

In fact, his book is important, not to find out how a plan might work, but to find out which plans are NOT going to work - have no chance of working. His point is that even before you are going to look at things such as economic viability, or even if you are going to look at reliable electricity from wind or the likes, he "wants the numbers to add up". It is not because the numbers add up that you have a workable plan, but if they don't already add up, for sure you'll never have a workable plan!

If they add up, you've passed the first test, and now you have to get into more detail. But if they don't add up, no point in looking further.

That's also why he puts coefficients "1" before all the energies. He's well aware (and discusses this) that not all energies are the same, and that conversions can be lossy. In fact, he goes "maximally electrical", because he demonstrates that this can give rise to energy economies. And first of all, "total energy" has to be found. We *then* still have to take into account conversion efficiencies, but that can only worsen the problem. If at a start, the power isn't even there, no point in calculating efficiencies of conversion, your plan won't work.

The "250 KWhr/day per person" in the US is divided by 2, simply because his argument is based upon the UK, and there, energy consumption is about half of it, 125 KWhr/day per person, and he has all his numbers ready for this quantity.

Now, living standards are higher in the US than in Europe, but one is nevertheless left with the sentiment that there must be more potential for simple economies of energy in the US without affecting lifestyle, as energy-saving measures which are already in place since long in Europe are not so much applied in the US as far as I understand. Now, as living standards in the US are higher, it will probably not be possible to bring US consumption down to Europe's consumption (halving), but some diminishing must surely be feasible.

So his book is not "to show the way", his book is more "a first realistic test for any energy plan before we look into the details". If the plan doesn't work at his level, no point in looking further.

vanesch

$316 !! That book is made out of photovoltaic cells or what ??

mheslep

A good part of the difference in per person energy usage between US and the UK must be attributed to the population distribution over a large country and consequent transportation needs, and not so much to lifestyle differences. For further evidence see Canada, which covers a vast land area and has a higher per person energy usage than the US but with a slightly lower standard of living.

signerror

I third this. Check it out:



From LLNL. Units are quads. It's a bit messy - it doesn't distinguish between electric energy and heat, so you have to figure that out from context - e.g., the 'hydro' bar is high-grade electric energy, whereas the 'coal' bar is low-grade heat, of which only 1/3 is converted to electricity, and the rest flows into the gray "electricity generation losses" bar. Bad design choice in my view.

At any rate, US households consume 4.64 quads of electricity out of the 12.46 total. And electric generation consumes 38 quads of primary energy (mostly thermal) out of 98 in total. So by my count, 14 quads - 14% of primary energy - goes towards residential electricity. Add in 5 quads of natural gas heating, and that's 19% of primary energy which is used by houses.

signerror

I question that. I suspect a large part of it is the climate difference, which result in much larger heating needs. For example, the Scandinavian countries also have anomalously high energy demand, but are comparatively tiny.

http://en.wikipedia.org/wiki/List_of...ion_per_capita

power per capita:

Iceland - 15.6 kW
Canada - 11.0 kW
USA - 10.4 kW
Finland - 9.6 kW
Norway - 7.9 kW
Sweden - 7.7 kW
...
France - 6.0 kW
Germany - 5.6 kW
UK - 5.2 kW

signerror

Here are his demand and supply graphs:

Astronuc

There are a number of specialty texts in the range of $300-$500. That's certainly daunting to an undergrad or lay person.

Articles at ScienceDirect are $31.50 now. The journal subscriptions are $$$$$$.


Meanwhile - here is an interesting assessment of the prospects of nuclear energy in 1966.
THE NUCLEAR ENERGY REVOLUTION—1966
Alvin Weinberg (Physicist and Dir. of Oak Ridge National Laboratory) and Gale Young.
pdf download available.

Very optimistic were folks back then.

drewk79

I am truly impressed by all the discussion going on in this one single thread. I feel a a little wiser after reading the responses every day.

If you take Mackay"s general numbers into account it is obvious our domestic energy policy is a large animal. I would think the best way to tame such a large beast would be to give the tools to the billions of people around the world.

I think technology will advance and bring us new exciting ways to harness large amounts of energy in a more cost effective way.

I am more interested in technology scaling down the tech we have today into systems that individual people could implement.

Boyle's Law says (I am paraphrasing I apologize) gas will spread out and take up the entire volume of a container and then begin to pressurize.

I think residential energy consumption is similar to that. I know in my house electricity is so cheap(?) I just use what ever I feel necessary at that point in time. It seems plausible to me the rest of the country works on a similar process.

We will continue to use energy in this willy nilly manner until we reach a level that puts pressure on the system.

I would like to see a test program that puts a cap on energy usage. Maybe not a hard cap but maybe just a beeper on your meter that beeps once you reach a set number of kwh each day. I think some people would see their usage and make more of an effort to reduce consumption.

I may be wrong and people may already be living without wasting energy but, maybe not.

If we could start budgeting our energy throughout the day we may be able to slow the growth of energy consumption. This may be slim in its ability to solve our needs but with a beast this big every shot helps.

vanesch

Well, all bits help, but as MacKay says, if everybody does a little, we'll achieve... little.

There's nothing wrong with individual ways of gathering energy and saving energy. However, don't forget: effective solar energy: 20 W per square meter (depends on location), effective wind energy density: 2 W per square meter. This is not very "compact", so unless you have a large property, your distributed techniques will only contribute a certain part.

Also, energy technologies often have economies of scale, so large scale systems are very often more cost-effective (and effective overall) than distributed systems. Large windmills are more cost-effective than small individual turbines, for instance.

One should be careful, in finding a realistic energy policy, that one doesn't put extra ideological constraints on the "solution" such that no workable scheme for the near future comes out.

Very simple: multiply energy prices by, say, 50. You'll see an effect. Maybe not the effect hoped for.

drewk79

The 20 watt per sq meter effective solar number. Is that what solar cells can produce? Or is that the total energy the sun puts out? thanks?