Sermon to the Sun Worshippers
by Jason Godesky
Constantine’s conversion to Christianity, or so the story goes, began with a vision in 312, prior to the Battle of Milan Bridge. Constantine supposedly saw a cross in the sun, and heard the words, “in hoc signo vinces” (”in this sign, conquer”). After painting his soldiers’ shields with chi-rhos, Constantine won the battle against Maxentius and became the sole emperor of the Roman Empire. What is less well known is just how popular Constantien was with various sun gods—his first encounter was with Apollo, and later, Sol Invictus, the Unconquerable Sun, an aspect of Mithras.1 Of course, sun worship is as ancient as it is universal, and certainly well-placed: the sun is the ultimate source of energy for all life on earth. However many steps removed we might be,2 we all live on solar energy by other means.
So, it’s only natural that latter-day sun worshippers would turn again to the Unconquerable Sun to solve the energy problems that currently loom over us. After all, the petroleum that we currently use in such quantities is a fossil fuel, energy stored by ancient plants and animals that ultimately came from the sun, a kind of bank for storing up what Thom Hartmann called The Last Hours of Ancient Sunlight. As Thomas Edison once told Henry Ford, “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.” Today’s sun worshippers tell us that photovoltaics will allow our civilization to continue along with its status quo as polluting fossil fuels will be replaced with clean, renewable solar energy, such as the case Travis Bradford presents in Solar Revolution.
In coming decades, solar energy is going to become the dominant energy source on the global market. This is true irrespective of possible increases in the price of fossil fuels; irrespective of possible global warming regulations; irrespective of government subsidies; irrespective of possible future technological advances. Even given conservative assumptions about all those factors, the tectonic forces at work in the global energy situation make solar’s dominance inevitable.3
Proponents of solar energy have pointed out that covering just 2% of the earth’s land surface would produce enough photovoltaic energy to replace the electricity use of the whole world. Of course, this is an unbelievably terrifying thought. While fossil fuels provide limits to growth that cap human civilization’s destructiveness at about its current level, Jevons Paradox has turned every technology that has ever been aimed at preserving natural resources into a greater consumer, not lesser. Schemes to reduce the amount of land needed for farming, for instance, have often been justified in terms of providing more land for “wilderness,” but they invariably result in less “wilderness,” because land use becomes more efficient. As we know, civilization is always compelled to grow.4 If today’s energy needs can be met with just 2% of the earth’s land surface covered in photovoltaic cells, why not support 13 billion people with 4%? Or 26 billion with 8%? Collapse remains inevitable even in this case, but whereas before the limits to growth were set by relatively benign problems like peak oil, now the limit is much higher—the point at which so much of the earth’s surface is covered in PV cells that we cause cascades of plant extinctions simply for lack of sunlight, and cut off the food chain at its base. The plan to replace our current energy usage with photovoltaics is, on the surface, the ultimate worst case scenario; it could be the deus ex machina that will allow us to delay collapse once again, but that delay is the first one to preclude any chance of survival for the human species. Indeed, it raises the terrifying prospect of the end of all multicellular life on this planet.
Of course, the ultimate cause of all collapse is the diminishing returns curve on complexity, and adding all the complexity of PV cells does nothing to solve that problem, and a good deal to exacerbate it, so perhaps such fears are ill-founded on the highest level. More importantly, let’s consider the energy calculations on which this “Solar Revolution” is based. Jeff Vail has recently added a very important note on this discussion.
There are serious problems, however, with the methodology used at present to calculate the EROEI of solar panels. Some authors claim that life-span EROEI for photovoltaics is as high as 50, but provide no information for how that figure is calculated. Others, such as Clarion University’s calculations, take a very limited view of energy invested in PV production, accounting only for energy use of the manufacturing plant itself. Under these assumptions, they understandably arrive at a very optimistic EROEI of 6:1 to 31:1. …
These embodied energy costs in the creation of a PV panel (called “emergy”) are difficult to calculate. We can regress infinitely, eventually going so far as to account for the portion of energy consumed by a rice farmer in China in order to fill the belly of a Merchant Marine captain shipping machine parts across the Pacific, ad infinitum. How do we actually get a composite sense of the total embodied energy in PV production? One way—and certainly not a perfect way—is to use the market’s ability to set prices as an equivalent for embodied energy. This is what I am calling “Price-Estimated EROEI Theory.” It basically suggests that the most accurate representation of the total energy embodied in any product is the price of that product. In our example above, the energy required to install PV can be accounted for by the cost of that service. The energy required to transport, to build a manufacturing plant, to employ workers, etc.—all component energy contributions in the production of PV increase the market price of the resulting product.
So what is the Price-estimated EROEI of PV? If we accept that the price of an installed PV system is representative of the energy used, then we can compare that price with the quantity of energy produced over the lifetime of that system (which also has a market price) and reach an EROEI ratio. There are variables involved here, but when we use market-price to account for the full spectrum of energy “invested” in PV, we reach an EROEI of approximately 1:1. This is dramatically different than the 6:1, 30:1, or 40:1 suggested by most sources. Which figure should we rely upon? While I recognize that price-estimated EROEI is not a perfect calculation, at least it attempts to account for the full spectrum of energy inputs, and the precautionary principle suggests that we should err on the side of this number (1:1) as opposed to the quite optimistic figures coming from the PV industry or the government.5
If the EROEI of photovoltaics is, as Vail suggests, closer to 1:1, then it is not an effective energy source—which would explain why it has yet to be adopted on a larger scale. While the price of PV cells fell for some time, this has leveled off in more recent years, suggesting that the costs of development have largely been paid off, and current prices are more indicative of the sort of “Price-Estimated EROEI Theory” Vail uses.
Even if this calculation is off, there are other problems with solar energy which may or may not be solvable. In the map above, not only the size of the black dots where PV cells would be deployed, but their location, is important. For maximum efficiency, PV cells must be placed in geographical areas that recieve optimum sunlight. Shifting weather patterns and even the regular cycle of night and day provide interruptions in service. This is important because electricity is more of an “event” than a thing—while means exist to store electricity in batteries, this storage which is so critical to providing regular electrical power from PV cells, has long lagged behind.
Solar panels have come quite a long way, and the electronic gadgets that monitor the system have come an incredibly long way, as have the inverters that turn the current to AC. …
But the batteries? They’re exactly the same. We’re on our third (I think?) set of batteries, but they’ve all been basically the same, lead-acid batteries that have to have water added periodically, won’t last forever, are extremely heavy, and are toxic to manufacture (although the recycling is pretty decent). Since the sun doesn’t usually shine at exactly the same time we want power, solar is going to stay on hold until someone figures out how to store it better than this.6
Just as important is the issue of transporting electricity from the PV sites into the cities dependent on them. Electrical currents encounter resistance, requiring boosters; it is simply impractical to transport electricity over very long distances as such a global PV replacement would require.
The potential for solar electricity supply must be examined primarily in relation to the task of meeting winter demand. The following derivation assumes an ideal Australian site, at the tropic of Capricorn where the average daily solar incidence on a horizontal plane in winter is approximately 4.25 kWh/ squ.m. (For convenience “square meter” will be indicated by “m” hereafter.)
This means that the sun would be approximately 35-40 degrees from vertically overhead throughout most of winter. Thus the incidence of solar energy on panels set at optimum inclination would be 5.18 kWh/d in winter, and collectors set at this angle will be assumed for the following discussion . (Note that this maximises the achievement for winter performance but to maximise annual performance the tilt would only be at half this angle.)
It will be assumed that for 8 hours a day electricity from solar PV plants will be supplied directly, and for the other 16 hours it will have to be stored before being supplied to consumers. Night time electricity demand is about one-third lower than daytime demand so in the following discussion supply from a power plant will be assumed to be at the rate of 1000MW for 8 daylight hours and 670MW for the other 16 hours. Although efficiencies above 25% are being achieved in the laboratory the efficiency of PV cells in use is reported by Kelly to be approximately 13%. (Evidence that actual performance is lower than this is given below.) At 13% efficiency each square meter of PV collection area would produce .67 kWh per day in winter in central Australia.
A 15% loss of this output in transmission from the inland generating site to the coastal consuming areas will be assumed, along with a 7% loss for inversion from DC to AC current. Czick and Ernst say that the loss would be 16% with today’s technology but that with HVDC systems it could be 10%. Hansen figures for the present loss rate correspond to about a 190% loss for a 1000MW power station transferring power 1000 km. Losses could be reduced if generating plant was located close to users, but for Sydney winter solar incidence would be about half that in Central Australia.
From these figures the overall efficiency of delivering electricity directly to consumers in the daytime would be 10.27%. In other words to deliver 1000MW, solar energy equivalent to 9737MW would have to fall on the collecting surface. Therefore to deliver 8 hours x 1000MW directly, 77,896MWh of solar energy would have to fall on the collector each day.7
Of course, the objection is always that new technology will change the equation by making PV cells less expensive. That, however, seems increasingly unlikely.
The cost of PV cells has fallen significantly over the past 3 decades, but the trend seems to have flattened out now. The cost for the Victoria Market system was $6/w (higher than that assumed in the above analysis.) If the cost per square meter of PV technology fell to zero the cost of the large collection area required in the above discussion would still be very high. If the PV material was sprayed at no cost onto 6 mm toughened glass at the mid 1990s wholesale price of approximately $60 per square meter, the cost of the glass alone for the above 87 million square meter collection area would be $5,220 million. (Littlewood 2003 estimates the cost of PV glass in 2003 at $50/m, and at $70-80/m for curved glass for concentrating systems.)
In other words the “balance of system” cost sets a difficult limit when the collection area must be large, and one that is not likely to be greatly affected by technical advance as structures are simple and major breakthroughs in their design are not likely.8
So what is the end result of all of this? The energy generated by the sun is the source of all life on earth, but plans to bottle it up solely for civilized use have more than a few problems that increasingly appear to be insurmountable. The sun worshippers are absolutely right for the hope and respect they have for that big, burning ball that keeps us all alive, but the threat of the photovoltaic nightmare coming to pass seems increasingly slim. As with most renewable energy source, individual photovoltaic use has a lot of potential, but as a society-wide answer to our general problem of overshoot, it does not seem to be able to live up to the hope of a deus ex machina to save us from the consequences of our way of life.
Why should we be concerned about this deux ex machinis scenario coming to pass?
The human population doubling time is 40-50 years, and if we get this much reprieve, perhaps more dei ex machinis solutions will be unleashed, extending the breathing room even more into the future. In any case, the interesting and comfortable times will continue for our generation, and at least a couple of generations after us.
Besides, since we are now effectively one global polity that can only collapse globally, the major impetus to increase population is removed. The old Prisoner’s Dilemma that forced relentless population expansion in the past is no longer applicable because the competition between individual polities is no longer possible in the same form as even a hundred years ago. Perhaps, the driving force behind civilization’s relentless growth in human population will completely lose its strength, and the population growth will become much smaller, while other kinds of economical growth will continue raising everyone’s standard of living.
Oh, yes, and increased supply of electricity has the potential of solving our growing water shortage problem. As for the engineering problems, we are a just in time species after all. If current solar energy problems are all engineering problems, they have a good chance to be solved just in time they are truly needed, just like all the solutions in the past.
Comment by _Gi — 7 November 2006 @ 4:10 PM
We don’t. The doubling time keeps shrinking. Such is the nature of exponential growth.
I very much doubt that. I think the comfortable times will be ending for most of us within the next decade or two.
You misunderstand how that works, then. Even isolated civilizations were compelled to grow or perish, because the polity level is arbitrary. Individuals, ethnic groups, businesses, and all the other groups and subdivisions within the polity are likewise driven to compete against one another, or be wiped out by those that do.
As mentioned in the article, these are pretty hard and fast limits we’re running up against. There’s not much that engineering can do.
Comment by Jason Godesky — 7 November 2006 @ 4:17 PM
I think that the billions of dollars required to transform civilization’s infrastructure to accomodate a complete switch from fossil fuels to solar power or any other alternative energy source contributes to the infeasibility of these “solutions”. And yeah, I can’t understand why so many people just love the idea of these “clean green” energy sources coming to save the day and erase all their environmental concerns. Well, I can understand why, it’s because they’re so engrossed in a finite system of exploitation they look towards its saint of technology to alleviate their fears. But as you stated in your post, the longer civilization goes, on the worse off humans and life on earth will ultimately be. So it’s clear that there’s no quick-fix “solution” to civilization’s problems. The whole system itself is the problem, and the solution is to destroy/abandon it.
Comment by pteridium — 7 November 2006 @ 5:19 PM
though I have never seen it in “print” TonyZ remarked to me when he visited that they are currently designing flexible PV sheets, that go on anything, similar to window tinting. He said that ANY surface could be covered in them. He also said that they currently are are made in 20 mile long sheets.
Does anyone know what he is talking about? Can TonyZ provide verification?
Comment by Rory — 7 November 2006 @ 5:56 PM
Something like this, perhaps? Myself, I’d kind of like something more like this to paint my yurt.
Comment by Jason Godesky — 7 November 2006 @ 6:05 PM
damn dude,you never cease to amaze me
Comment by Rory — 7 November 2006 @ 6:51 PM
Jason, isn’t the material needed to build PV cells limited? I haven’t looked into the issue carefully, but I thought we wouldn’t have anywhere near enough material to cover 2% (or whatever) of the planet’s surface with PV cells. Am I correct?
Comment by Hasha — 7 November 2006 @ 7:18 PM
“The doubling time keeps shrinking. Such is the nature of exponential growth.”
No, the nature of exponential growth is that the doubling time is constant.
Comment by DigitalDjigit — 8 November 2006 @ 1:24 PM
Hmmm, true, so we’ve got something even more than exponential growth, because the doubling time has been shrinking.
Comment by Jason Godesky — 8 November 2006 @ 2:02 PM
Yes, ofcourse the civilization will strive for growth. However, the population growth in particular seems to no longer provide competitive advantage.
The population growth is strongest a poorest places with bad ecology and high death rates at the moment.
Why should a population of highly developed place like Western Europe grow at high rate? What good will it do? Modern warfare does not require large numbers of foot soldiers. There is no land to conquer. The unemployment is already high, so additional labor source is not needed. Businesses do not need large population increases to compete among each other.
Ethnic groups are in the process of being thoroughly homogenised, so that this competition drive is being reduced. Individuals certainly cannot compete in the West if they also desire large families. It is not economical to raise a large family for most of urban dwellers. Singles will outcompete multi-child family persons in most professions simply by virtue of having more available time to devote to perfecting and adapting their skills.
I still cannot see why you see large population growth as a competitive advantage
The stuff you want to spray on your yurt may prove to be scalable.
Comment by _Gi — 8 November 2006 @ 5:08 PM
As I’ve explained before, population growth has everything to do with complexity. The more complex a society becomes, the lower the marginal return on a child becomes, because the cost of raising a child is higher. A more complex society necessarily means that there’s more to learn in order to reach basic cultural fluency, and that extends the period in which the child depends on his parents. In the U.S., it’s 18-25 years already. Compare this to a simpler, agrarian society where, at three years, the child can be sent into the fields and begin reaping a profit. In a less complex society, children are not economic burdens, but economic assets.
However, the high level of complexity enjoyed by the First World depends upon the lower level of complexity in the Third World. You can shift this geographically or culturally, but you cannot change the global trajectory, because every rise in complexity you provide in one area results in lower complexity somewhere else (which is precisely what you’d expect, once you understand that complexity is a function of energy). Thus, global population is, was, and ever shall be linked to global food production—hence, the Food Race.
Comment by Jason Godesky — 8 November 2006 @ 5:15 PM
So, complexity is a function of energy.
As energy inputs increase, I would expect complexity everywhere to rise, perhaps not equally.
A Third World today is still a more complex place than it was a hundred years ago, and the trajectory all over the globe is for complexity to increase. When they start producing hundred dollar computers for the third world consumption, what does that do to complexity in the third world? When the multinationals set up factories in Third World nations, does that increase complexity over there? When citizens of Third World nations get a larger chance of receiving higher education, does that increase complexity?
American South used to be a very poor place even fifty years ago. But look at it now. With energy inputs from oil, it grew in complexity tremendously. If energy inputs are increased, wouldn’t it happen to other places?
If energy truly were “too cheap to meter”, would there be a reason for wars? Or for a Food Race. The clean drinking water could be had in large quantities through desalinization, which is merely too energy consuming right now to be scalable. The food production is simply putting calories into the soil to get edible stuff back. The machines that do the work require trained workforce to operate, no matter where these machines are deployed.
The Third World right now is more complex than the industrial world of a hundred years prior. The complexity increased. It will continue increasing, because that is the only way our civilization solves its problems everywhere they appear. Unless lack of energy stops this trend, the complexity of global civilization will increase everywhere on the globe.
Comment by _Gi — 8 November 2006 @ 6:39 PM
Regarding the shrinking doubling times, I think this was the last we saw of them.
The Earth population is not expected to reach 8 billion by 2020, which would be the next doubling time from 1975.
Comment by _Gi — 8 November 2006 @ 6:45 PM
And complexity brings continually diminishing returns, which is why increases in complexity ultimately won’t save us.
The reason the doubling rate is slowing instead of increasing is because the planetary resource-base is starting to creak and groan under the weight of the stress our numbers place upon it.
Comment by venuspluto67 — 9 November 2006 @ 2:14 AM
The predictions that our population growth will begin to slow is based on the kind of logic you propose above—that complexity will continue to increase. But you’re woefully incorrect on two fronts. First, complexity has not increased in the Third World; it has dropped, and precipitously. The post-colonial legacy is barely controlled chaos; before the intervention of European empires, there were significantly complex cultures in these areas. The Amazon was once a food forest cultivated by its native cultures; those cultures were decimated by smallpox and conquered. The complexity of the Zulu was broken by the British; now you have the various rebel factions and profiteering governments of southern Africa.
The second point you miss is that complexity doesn’t just keep increasing. We don’t get more and more energy just because we need it. The efficacy of complexity is subject to diminishing returns. In other words, there’s an asymptote of the effect complexity has, and we’re approaching it.
Comment by Jason Godesky — 9 November 2006 @ 10:20 AM
Hm. The “limit on growth” was estimated back in the 1960s as 400 Billion humans living in Arcologies spaced equally around the Earth. This was based on the amount of solar energy incident on the planet and how much each person required for a subsistence lifestyle. Yes, the Carnot Cycle was factored in and it was assumed that all terrestrial energy sources had already been exhausted or were incidental.
Oh, and if you gave every person currently alive 2000 sq ft of living space we could all living a building somewhat smaller than the state of Texas so we’re nowhere near any “limits of growth” based on solar power.
Oh, another point. The birth rate in the top 10 technologically advanced nations in the world is either at or below the theoretical replacement value of 2.1 per couple. it’s the 3rd worlders breeding like rabbits out there. As a country matures technologically (and hence its ability to feed its own people) its birth rate plummets, Malthus be damned.
So we’re never going to get to that 400 Billion mark or anywhere near it. Converting 2% or 10% or whatever percentage of the Earth’s surface to energy production isn’t going to doom us; it will probably save us because this will encourage the 34d world to advance more quickly and then reduce its birth rate to something more sustainable.
Put me down as a Roddenbury.
Comment by Orion — 12 November 2006 @ 9:57 PM
That’s a statistic so common that even my usual answer has become cliche: “Yes, and if we were to only eat what’s directly under our feet, that might even be relevant.”
That kind of naive calculation might work for photosynthetic plants, but for any organism on any trophic level higher than that, you need to factor in ecological footprint. Right now, it takes fields of crops covering over 40% of the earth’s land area to feed the 6.5 billion humans we currently have. You might make that stretch a little farther if you forced everyone to be a vegetarian, but even our current situation—wherein 40% of the planet’s land area is dedicated solely to a single species—is utterly catastrophic. The current mass extinction is, through various means, caused by the pressure this situation exerts on all other life on the planet.
I’ve written several articles debunking this oft-quoted “fact,” which you should have no trouble finding in our archives, but to rehash it once more, what limits reproduction is complexity. In less complex societies, the marginal cost of a child goes up. In Mali, a child can be economically viable in three or four years; in the United States, even a bachelor degree is sometimes not enough, so let’s put it at a mean of about eighteen years—meaning that the time during which parents must invest in their child is between 4.5 and 6 times longer. Meanwhile, children in Mali are a source of labor; with a simpler society, extended family structures are the norm. Children stay at home and work the fields. In the United States, greater complexity leads to neolocality; when children finally are economically viable, they move out. In other words, children are economic burdens in the First World; to even maintain replacement fertility, pure sentimentality must outweigh economic rationality. In the Third World, however, having lots of children is the one sure ticket to prosperity.
From this, you might conclude, as you do, that we’re on our way to a stabilized society. This is an extremely naive view that neglects any examination whatsoever of the foundations of First World complexity—namely, through means both direct and indirect, the exploitation of the Third World. Our way of life is simply too expensive for us to actually pay for; so we make others pay for it. Externalized costs—externalized to the Third World. In other words, First World levels of complexity are dependent on Third World levels of complexity. So there’s only so far the Third World can develop before that development threatens the complexity of the First World. We could change place, but there cannot be a First World without a Third World; there cannot be rich without poor. These are means by which we shift where we allot our resources and growth, and even put them in different places, but no matter what happens, human population remains a function of food supply, and nothing can change that.
So covering 2% of the earth’s surface with PV cells is very much a threat, because it can’t eliminate the Third World. It might move it around (in fact, it probably will; the World Wars, the Depression, and Europe’s post-colonial legacy are largely the result of the shift from coal to petroleum), but it cannot eliminate this systemic relationship. So long as our energy supply is growing, we are locked into a positive feedback loop of infinite growth that can only end when it hits some limit to growth.
My hope is that it’s something benign like peak oil, because if it isn’t, then it becomes something really frightening, like our extinction. With PV cells, that might not even just be our extinction, but the extinction of all multi-cellular life on the planet.
Fortunately, Roddenberrian plans have always been shallow and naive, and have never taken into account the full cost of the measures they call for. Hence the “unintended consequences” that accompany nearly every major invention that we’ve ever devised (which are often as bad or worse than the problem the invention originally aimed to solve). The potential for PV cells to actually fulfill the nightmarish prophecy that short-sighted “Roddenberries” predict is increasingly unlikely. It seems that life on earth will be OK after all, and humans will have to accept a world of true peace and prosperity, regardless of what doom the “optimists” predict for us.
So I’m very optimistic that the “optimists” are dead wrong on this one.
Comment by Jason Godesky — 12 November 2006 @ 10:32 PM
You’re not following. There isn’t room for an edge, because you’ve only got enough room to carve up the whole town into a bunch of biointensive micro-farms. They need edge, they need to be up against something that’s not another biointensive microfarm! If you have to put a small forest between each of those microfarms, you’ll be lucky to support Northbrook’s population with the northern half of Illinois, much less the town’s area.
Wait a minute. I didn’t think the gardens actually needed that edge in order to survive, I thought that they just needed it to be more productive.
So would the micro-farms die without their edge, or be less productive?
Do you have any other evidence from other sources, or any evidence here, to back up the necessity that much of Northern Illinois would be needed to feed Northbrook’s population? I read your citation with Jeff Vail, but his piece is about redundancy and resiliency. I didn’t see anything about it being absolutely essential.
Comment by Taylor — 13 November 2006 @ 3:49 PM
Taylor appears to be picking up the discussion from this forum thread, though it’s hardly relevant here.
Less productive. Much less productive. Such that the numbers we’ve been assuming no longer work. If you don’t have edge, you’re talking about conventional farming techniques, and I think we’ve already established how well those work.
Sure. Read anything about permaculture, and the importance of edge will be emphasized. Then read anything about forest ecology, and you’ll begin to understand how much area it takes for a healthy forest to develop. Some of my favorites are Toby Hemenway’s Gaia’s Garden and Dave Jacke’s Edible Forest Gardens. But overall, this is a really, really basic subject, so you could literally fill a library with citations for this—and they have. If you go read anything on these topics, you should come across ample support very quickly.
The Vail link was generally about redundancy and resiliency, but I was mostly referring to the figures for Jeavons’ biointensive technique, with special attention to his part: “The use of efficient layout, soil growing processes, exploitation of edge (especially between ‘garden’ and ‘forest garden’), and other principles well laid out in the fields of permaculture, Fukuoka method, and bio-intensive gardening show that high yields are possible with relatively low effort and little space.” In other words, without proper edge, all the rest of this is moot. You’re not going to support 10 people off of an acre if that acre isn’t surrounded by forest.
Comment by Jason Godesky — 13 November 2006 @ 4:00 PM
> “If the EROEI of photovoltaics is, as Vail suggests, closer to 1:1″
It isn’t.
He bases his calculations on the following assumption:
However, his assumption is not reasonable:
World energy consumption: 421 quadrillion BTU (2003 estimate)
World GDP: $45 trillion (2005 estimate)
Thus, we get 421 quadrillion btu / 3413 btu per khw / $45 trillion = 2.74 kwh per dollar — or $0.36/kwh — as a world-wide average, and hence as the reasonable default for a price-based estimate of energy content.
Based on that, his calculations give an EROEI of 3.5:1 for PV, which is still quite worthwhile.
Comment by Anonymous — 14 January 2007 @ 4:06 PM
2% of the earth’s land is an area larger than Argentina. That’s alot.
Comment by Andy — 14 January 2007 @ 11:57 PM
Jason,
RE: #17
I’m kind of a demographics buff (among other things) so it’s interesting to come across a fresh look at an old problem. The complexity angle, I think, merits consideration as a part of the mix of what causes go into the decisions people make in having children.
I do disagree with, however, your standard, if implied, technique of comparing a society like Mali with that of say the US. It makes more sense, in my opinion, to compare Mali with Mali on a time-line and correlate total-fertility-rate (TFR) with various socio-economic factors. I think this would reveal that generally speaking, bad times lead to lower TFR, good times lead to higher TFR. I believe this would hold true regardless of the complexity of the given cultural reference group, although the complexity issue might be an important determinant in the baseline TFR for that particular culture. The US had a very high TFR in the 19th century when society was arguably ’simpler’ but there was also a huge ‘petrie dish’ mostly uninhabited in which to expand.
Comment by Eric — 15 January 2007 @ 2:18 AM
The comparison is certainly not meant to understand the dynamics of Mali, but rather, to understand the dynamics at play in the world system as a whole, wherein some countries benefit while others suffer from shifting complexity, and with it, energy and population.
Comment by Jason Godesky — 16 January 2007 @ 12:19 PM
Jason:
Somebody just posted the map with the theoretical solar collectors (most of which are the size my home state of Wisconsin if not bigger) on reddit.com. I posted a link to this article in the comments (introducing it as “a nice, big turd for the solar punchbowl”
).
Comment by venuspluto67 — 7 April 2007 @ 12:11 PM