Saturday, August 26, 2006

Energy: Part 2: Energy Sources for Civilization

3a. Solar

Personally, I don’t think solar power will cut it. The primary reason why is that solar power isn’t being proposed politically for the purposes of providing actual electricity. It’s being proposed as a magician’s distraction to seize our attention while nothing is done to actually de-regulate energy production. A sop to placate us. Perhaps a plant or two will be constructed, as pet projects for senators and contract seeking eco-firms.

The second reason why is that solar energy is very very diffuse. It is not “free energy”. It requires refined silicon panels, which are expensive to make. It requires batteries to store this energy during night, transformers to step it all up to usable voltages. Per square meter, there is just not that much of it. I have heard over and over again “If we just pave our roofs with solar panels, we can meet our needs”. Will this cut it? Let’s see. At Earth’s distance from the sun, it receives about 1370 W/m^2 in terms of energy. Only about half of this energy makes it through the atmosphere. And the sun is only in the air half the time. So you’re only getting about 340 W/m^2 on average.

If we assumed 100% efficiency of our panels, our storage process, transmission, and our conversion of that energy into chemical energy, we would only need about 4100 km^2 of collection area to do the job. But assuming 100% efficiency is a good way to be totally divorced from reality.

There are two main types of photovoltaics out there: silicon and gallium arsenide. Gallium arsenide solar cells are about 37% efficient on satellites, and 26% efficiency has been achieved terrestrially. Link However, we can’t make miles and miles of panels out of Gallium Arsenide. We’d have to go with the silicon panels.

Silicon solar panels are about 12% efficient at room temperature (at colder temperatures, the cells are more efficient. However, considering that the cells get their energy from sitting in the hot sun, this is somewhat self-defeating). Link

I don’t have any solid sources, but charging and discharging battery banks is likely to be about 30% efficient. We need the battery banks to store energy for cloudy days, or for periods when the efficiency falls below optimal, or when usage peaks. Since solar power doesn’t output at a nice predictable rate, these are required to smooth out the transition.

If we then, finally, assume a generous 50% for the efficiency of producing and transporting the artificial fuel, we’ll end up needing something like 230000 km^2 (87,000 mi^2) of solar panels. (a square 480 km (300 mi) on a side).

That doesn’t sound too much like free energy to me. Don’t even get me started on the fact that these solar panels have to come from somewhere (refining silicon from sand, ect) and that they have to last sufficiently long to return the amount of energy it takes to produce them in the first place.

Solar might be an option for powering small appliances and lighting, or road-signs. It might even provide remote power for camping. But it’s not going to replace gasoline.

3b. Bio-diesel

This is sort of like the organic version of solar power. Plants are basically solar powered organisms. They store their energy in sugars and other substances that we can refine into various hydrocarbon fuels. They are one step over solar in one regard – we don’t have to expend the same energy refining silicon. Plants are self-constructing.

However, we do have to till the soil, provide irrigation, ect. Furthermore, these plants are going to be in direct competition for our most arable land, which we need to feed the world. At least, if we continue to want to be the bread-basket of the world. We do have plenty of arable land available, however, so let’s assume that the same people who dream of bio-diesel powered cars will also give their parklands, wilderness, and forests over to bio-diesel farmers.

However, you need to gain sufficient energy from the refined fuel to afford harvesting it. Remember, this is supposed to be our primary source, you can’t pass the energy debt off to something else. Also, plants are much much less efficient, from an energy collection perspective than photovoltaics. So the amount of farmland necessary to implement this is likely to be vast. (At this point, I’m running out of time, so my discussions are going to be a little less quantitative).

3c. Windmills

How fast do alternative energy buffs intend to wave their hands?

3d. Tidal Generators (I like this one)

Tidal generators actually have potential for use as a primary source. The tides are predictable, consistent, and, most importantly, they pack a punch. Thousands of tons of water moving back and forth on a day to day basis can be made to move back and forth through our turbines into artificial reseviours, providing significant power. They, like hydroelectric power, require pouring a lot of concrete in some highly inconvenient areas, however. It would require a significant re-arrangement of some coastal property, most of which is densely populated, to make this work.

3e. Enviro-Luddites in Hamster Wheels

Egads! I’ve got it! Race you to the patent office! Promising, very promising, but it would require them adopting a somewhat more substantial diet than tofu and organically produced vegetables. And then it would devolve into another version of bio-diesel.

3f. Coal Power

I’m rather unsentimental about the environment. My main concern about energy is from a human perspective. You’d have to be pretty darn convincing to get me to believe that any old industrial eyesore or the death of the purple-spotted-worm is too much to ask of the environment if it benefits mankind. But even I would be opposed to coal power on environmental grounds. There was a point in time when London was choking on suffocating yellow fog due to their prodigious burning of coal and local weather characteristics. Coal power produces pollution. Real pollution. Particulates, sulfur, smog, all in non-trace quantities - not just the CO2 you get from burning oil.

The recovery of our environment from the industrial revolution began, believe it or not, when we converted from steam engines, wood furnaces, animal power and coal boilers to oil internal-combustion driven processes. Far from being a despoiler of the earth, the IC engine saved us from what was, at the time, the only other alternative.

Furthermore, how fast and recklessly do you want to mine this stuff? Can it be longwalled at the rate it would take to supply 1.4 terrawatts of power? At such a frantic pace, it’s likely that miners would be routinely dying in mine collapses. The other alternative is to strip-mine it, which means removing hill-sides, scraping it all out, and tossing the dirt back on top.

What on earth are we going to do with all that sulfur? Better figure out a way of making solar panels out of it, and fast. Otherwise your water will end up tasting pretty funny.

3g. Am I going to say it? … The word … the awful, evil, violent, hideous concept which will kill us all? Yes.
NUCLEAR POWER (my favorite, obviously)


Capital letters are appropriate. Nuclear power has the most to offer us, IMO, out of all our energy sources to date. It is the most powerful (by several orders of magnitude) compact force that mankind has managed to tame. It’s ironic that the most publicly hated and feared means of generating electricity is the one that came closest to fulfilling all reasonable demands of environmentalists, industrialists, consumers and people who want nice open-spaces (as opposed to flatlands paved with photovoltaics). Some people, however, in the absence of being able to find reasonable objections to something they oppose, will begin to fling unreasonable objections with desperate fervor.

To hear opponents talk, a nuclear reactor is such a dangerous and unstable device that it’s ready to explode at any moment in a furious mushroom cloud. That the waste products (spent fuel rods – the same size and almost the same mass as the ones that went in in prior years) constitute some mortal danger to the public. Nothing could be further from the truth!

Nuclear waste is no more or less voluminous or massive than the rods which went into the reactor in the first place (not counting sections of de-commissioned reactors, which also have to be cut up and stored). And one nuclear fuel rod will go a very very veeeery long way. We have 103 nuclear power plants. These power plants provide 20% of our nations electricity, however. And in their years of operation, we have only produced around 50,000 tons of waste. That sounds like a lot, but compare it to billions of barrels of oil every year. Compare it to the hundreds of millions of tons of other products passing around our society every year. This waste takes the form of solid metal objects. The current storage method is to put these materials into dry-casks designed to keep the waste sealed and dry for millennia. Unfortunately, we’re currently storing these casks at the reactors themselves, or in temporary storage throughout the country, since no one wants a permanent disposal site built anywhere.

We could easily store this volume of waste in a single large storage site, like the ohio salt domes, for instance, or any other geologically stable region. Currently, our country is trying to obtain permission to bury it in a fortified hole in the side of a mountain in the middle of the desert, and even this meets resistance.

Supposedly, nuclear waste has to be stored for millions and millions and millions of years, forever. This crazed requirement is yet another unreasonable obstacle that is thrown in the way of nuclear power companies. While the radioactivity of the spent rods does persist, the output exponentially decays over time. Eventually, you’re left with the basic radiation that was present in the original uranium. It’s dangerous to be near the waste while it is unshielded and fully concentrated, but while it is underground in water-sheilded containers? Our current regulatory standards are to construct a device that can store the waste against corrosion and water for 10,000 years.

Still, people worry that some-day, in the far far unimaginable future, water will eat through the walls of the armored container and all hell will break loose. In reality, since the containers are likely to be stored in a dry environment, you’ll have to wonder if it will leach away into the water through the armored storage container at a rate appreciable enough to build up noticeable concentrations in anything, much less migrate into used ground-water reseviors. It’s almost as if the waste is to be imbued with some malevolent intent to poison us. We’re talking about solid, chemically inert metal rods, not malevolent entities out to destroy the world.

They also worry that our distant descendants (presumably too stupid to understand what nuclear waste is, or to avoid the dangers associated with breaking into our waste-storage facilities) will dig it up and eat it, or something, and must be warned of their impending doom. Hence ridiculous measures to post enduring warnings and hieroglyphics (see national geographic). I fully anticipate our descendants will break into our nuclear waste storage facilities. They’ll want the waste, because it actually isn’t “spent” by any but our present irrational standards. In fact, we’ve used less than 1% of the energy we could presumably wring out of the uranium in the rods. There are reactor cycles that can re-process that “waste” over and over and over again into newer generations of nuclear fuel by using a “breeder reactor” to breed plutonium and more U-235 from the inert U-238. (the non-fissioning uranium that composes most of the metal, it is only the U-235 that fissions). This process could extend the available enriched uranium from a centuries long supply to one that could last us millions of years (effectively forever).

Nuclear sources:
eia.doe.gov Article
www.eurekalert.org Article
http://www.uic.com.au/wast.htm
Link
Link
National Geographic Article

(Aside: Geez. I’m having a hard time finding numerical references. Try typing “Nuclear Waste” into a search engine to see just how wild-eyed the paranoia over this waste is. You’d think it was nerve gas or something. A poll popped up – apparently the vast majority of people believe that the US has the most nuclear waste per capita, which is totally nonsensical, seeing as how we are far from the world leaders in per-capita nuclear energy use!! This is an important insight into emotional thinking. Nuclear waste isn’t an actual product of an actual physical process to most people. Most people think of it as merely another indicator of eeeeevil. And “everyone knows” we’re the biggest selfish polluters on the planet.)

Other benefits of nuclear power are that it has a very small footprint on the world (unlike solar, wind, or bio-diesel, a nuclear plant doesn’t require thousands of square miles of coverage to do its job), it emits no carbon dioxide, it actually emits less radiation than coal plants (which actually spew trace uranium into the air with their particulates). In fact, unless your containment dome (a large concrete bunker over the reactor designed for preventing even a catastrophic internal explosion (larger than anything a reactor is capable of producing, from a nuclear professor I know) from allowing exposure to the air) is broken open somehow, they emit nothing at all.

When evaluated on its merits, nuclear power is a dream come true. I think it will become our primary energy source, no ifs, ands, or buts. Hydro-power and tidal power will also continue to provide industrial scales of energy. Wind and solar power will provide non-automotive residential energy at best. If we want to replace gasoline, I mean really want to do it, as opposed to merely sneering at gas-guzzlers and feeling good because we care, then your only real options are nuclear and hydro.

5 Comments:

Blogger James Aach said...

I'd like to see conservation be the #1 energy priority. No matter what you're shooting for - slowing global warming, less world-wide political instability, environmental gains, it's a winner. Only politically (in the US) does it tend to be a loser.

If you would like a realistic portrait of the nuclear energy industry, and also wish to be entertained at the same time, see http://RadDecision.blogspot.com for a thriller novel on the topic by a longtime nuclear worker (me). It's free to readers - who seem to like it, judging from their homepage comments. In the text I address some of the issues you mention in your post (diffuse solar in particular), and a great deal more of them in the comments section for each episode.

Sunday, August 27, 2006 9:22:00 AM  
Blogger qwerty182764 said...

Thank you for your comment. I'll be sure to read your novel.

As for conservation, I think it tends to be a political loser because it's basically another way of saying "do without". Another reason is that it's a tragedy-of-the-commons scenario. The only people who lose in a conservationist society are the people who play by the rules and conserve! People who set themselves up as exempt from the rules (politicians, celebrities, lawyers, aristocrats - they're not going to be the ones doing the 'conserving'. It would be begging for favoritism and heirarchy). So it's sort of a self-punishing situation. It would be far more stable if we have a way to actually meet our demand for energy. I think nuclear power may be a good way to do that.

But, I'll see what you have to say about it all in your novel, seeing as how you worked in the field.

Sunday, August 27, 2006 11:32:00 AM  
Blogger Robert Reed III said...

Check out OTECs. You can find links to this energy source on my blog. Even while solar power may be expensive, it may end up being our only option. When we are speaking of the survival of civilization, then the cost of building the source should mean nothing, IMO.

Wednesday, August 30, 2006 4:54:00 PM  
Anonymous Anonymous said...

"They also worry that our distant descendants (presumably too stupid to understand what nuclear waste is, or to avoid the dangers associated with breaking into our waste-storage facilities) will dig it up and eat it, or something, and must be warned of their impending doom."

that's my favorite part of the article, funny as hell, made me laugh out loud. good argument for nuclear energy!

Thursday, November 02, 2006 5:25:00 PM  
Anonymous Gordon said...

Yes, nuclear's gotten a bum rap for a long time; I think in the U.S. we've been too stuck on fusion and let our fission research really dwindle, when there is likely a lot to be gained from advanced fission reactor and waste disposal technologies.

I've wondered about tidal/ocean energy for a long time, especially since Marshall Savage and the other First Millennial Foundation (now Living Universe Foundation) folks began plugging that. As I understand it, their concept's weakness was more with the ocean concrete construction technique they promoted than with the ocean thermal energy concept (OTEC), though I think there's a lot of potential just with wave/tidal energy too.

By the way, I wouldn't count solar power satellites out for the long term. I worked at JSC years ago with one of the engineers involved in the NASA study (that came out pessimistic about SPS). He told me the study was flawed because of the extremely conservative assumptions, and that SPS could be quite viable.

I think the bigger problem there is that it would take such a large-scale project just to do a proof of concept.

Thursday, November 30, 2006 9:41:00 AM  

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