Physical Sustainability

Sustainable Civilization: From the Grass Roots Up
Chapter II - Physical Sustainability Factors and Limitations - 2
 
The present infrastructure and ideologies of civilization developed in an era of cheap abundant energy, expanding population and what seemed to be unlimited resources. All of this is ending. Given present knowledge and science, humans are faced with physical limits. We need to recognize what these limits are, and re-think our civilization from the grass roots up, not bumble blindly on.
=== History ===
In this past 100 years, the incredible development of our global society and population expansion was made possible primarily by oil, which provided a store of cheap, concentrated, portable energy, as well as plastics, medicines, clothing, pesticides, paint, and thousands of other products.
God blessed the United States with an original supply of about 260 billion barrels; only Saudi Arabia had more. From 1859 to 1939 the U.S. produced two thirds of the world's oil. Part of the motivation for Japan and Germany in WWII was their lack of resources to cope with the combination of expanding population and increased per person demand, with a particular shortage of energy in the form of oil. It could easily be argued that American oil, and the industrial output it nourished, was a major factor in World War II, as was our hydroelectric power which allowed for production of great quantities of aluminum for aircraft. For oil, taking California as an example, this one state had more than all Axis territory combined. As recently as 1950 the U.S. was producing half the world's oil.
Today, we now don't produce half our own oil, and absent a scientific energy breakthru, we should probably preserve it for national defense use as the oil era ends. 
Starting immediately, should make every effort to use our power, technology, knowledge and resources to transform our oil dependent society into one that is sustainable, above the level of mere subsistence. That said, much of the remains of our inheritance must be used to play world policeman and prevent war on a global scale. We will, probably, continue misguided programs that sustain a growing underclass of individuals who return nothing to society. 
With the food production and shipping made possible by oil, as well as energy to transform the landscape, and overcome the environment, humans have overpopulated like a plague over the planet. For the present, humans can live in places, and in concentrations that are impossible to sustain without oil.
Our strategic reserves, established as a "buffer" against OPEC economic actions, and for security use, represent less than 30 days supply at our normal use. And, these reserves can not be pumped faster than a flow which would be around 17% of our normal daily use. So, the governmental reserves, if NOT used for the military, could keep 17 percent of the economy going for a few months. Our total domestic supply could only operate the nation's present infrastructure for a relatively brief period. Until we have an alternative, we're stuck providing security to keep the foreign oil flowing.
In 1859 when oil was struck in Pennsylvania, Americans traveled on horseback; in 1969 they drove Mustangs and flew to the Moon. In 2069, those who survive will probably walk. Will your heirs, if they live, live in a comfortable self-reliant modern city, or hide in caves?
=== Fossil fuel follies ===
Returning to *King coal"
A century or so ago, humanity switched, in large part, FROM coal TO oil as the primary fuel. The U.S. has perhaps the largest remaining coal supply, estimated to be around 270 Billion Tons, currently being used at the rate of around 1.7 billion tons per year. (158 years at 2006 rate)
Every barrel of oil has around 6,048,000 BTU, and every ton of coal around 20,000,000 BTU (equal to 3.3 barrels of oil). 
If coal were as readily accessable, easy to process and use, the U.S. coal supply is equal in BTU's to around 890 billion barrels of oil. I've seen on the web conversion efficiency rates of 40%, so the conversion uses about 7.6 billion tons of coal to make 10 billion barrels of oil, for a combined coal and liquid fuel lifespan of 29 years, with a total of 290 billion barrels of oil.
But of course, BTU's are not the only issue. There is the dangerous work of mining, the environmental damage left behind at the mine, the pollution from coal use, and it is of course NOT able to directly power most of the present machines.
In June 2006 the reports are that a coal to liquid fuel facility would cost $7.5 billion for a plant that could produce 150,000 barrels per day (around 54 million per year). It would take 182 of these facilities to replace the U.S. annual use of 10 billion barrels, costing about $1.4 trillion to build. 
Amortize the plants over the production in their useful life and without interest or profit for anyone the plants cost $12.96 per barrel. 
In 2005 the price of coal used at synfuel plants was $42.78 per ton, so the coal cost for each barrel is $32.41. Taking efficiencies into account and amortization of the construction costs, with no inflation, and no demand increase, the production cost of coal-oil is around $44.37 per barrel. 
For perspective, the per barrel well-head cost of oil in Saudi Arabia in the 1950's was 7 cents. In the early 1990's it was little over 50 cents. The estimated cost in 2005 is $2.80, while a barrel is selling for over $60.00. (21 times cost) At that ratio, coal to oil would retail at $931.77 per barrel, with a gallon of gasoline at around $22.18 per gallon. (Your calculations may vary.)
The coal-oil investment would represent a 29 year timeframe to come up with something else. (Less when you consider rising demand and increasing difficulty mining.) Will we re-throne King Coal? It is at the top of the President's 2006 Advanced Energy Initiative.
=== Green house gas & global warming ===
Without some level of greenhouse gases (i.e. , water vapor, & methane) most of the Earth would freeze. For perspective however, the present (400 ppm) level of is reported to be higher than at any time in the past 650,000 years. The level of these gases are effected by factors such as the number of animals (including humans), plant cover, in particular forests which can store a great deal of carbon, and the release of "new" carbon from the human activity of use of fossil fuels.
We seem to be clearly approaching a level of greenhouse gases where there is potential for dramatic global warming, telling us of the need to cease fossil fuel burning. At the same time we are warned of impending peak oil, where oil cannot be pumped fast enough to meet demand. The clear consequence of peak oil, to be followed by decline, probably quickly in pumping rate, is the dramatic increase in the price of all oil derived products and services, and the end of many of such.
The Kyoto treaty is often presented as an essential example of international cooperation to reduce carbon emissions. However the treaty is clearly flawed, in that it fails to require that quite a number of countries actually comply, even if they join in the treaty. 
China, with an estimated population of 1.3 billion (and still growing) has become essentially THE worldwide source of a large variety and volume of consumer products, and which in its burning rate is (2006) the #2 volume polluter in the world, rapidly catching-up with the U.S., is for treaty purposes EXCLUDED from compliance. 
As of 2006, China is constructing the equivalent of one large coal-fueled power station EACH WEEK. Over their roughly 60 life span, these facilities could collectively put into the atmosphere the amount of that has heretofore been released by ALL OF THE COAL BURNED SINCE THE DAWN OF THE INDUSTRIAL REVOLUTION. 
Sulphur dioxide emissions in China rose 15% in 2005. There are areas of China that are black from coal soot and slag heaps. 
The rising demand in China for all resources puts it a #2 for fossil fuels, and #1 for virtually everything else. Cement, , , corn, soybeans, , and in particular . 
Despite extensive expansion, there remain even significant cities where electricity is not yet available in private homes, and only intermittently for businesses. China has underway nuclear plants expected to average one new plant each year for the next 20 years. To transmit and use this electrical capacity, China will need a lot of copper. So much that estimates are that if every ounce of remaining copper in the world were mined and sold in China, the demand could not be met. 
The Canadian tar sands project in Calgary, and the pipeline to carry the oil to market is China funded: from Canadian tundra to Beijing taxi, 17 days. 
Pollution, is pollution. , is , the atmosphere does not care where the was generated, it still effects the temperature the same.
=== Shale oil ===
"Colorado , Utah, and Wyoming harbor a store equivalent to 2 trillion barrels of oil--more than all the crude that has been produced worldwide since the petroleum age began. A Rand study estimated recently that 800 billion barrels might be recoverable, which would be more than triple the proven reserves of Saudi Arabia and could fuel current U.S. demand for oil for another 80 years. But there’s more to the story.
As with oil sands, enormous amounts of energy would be needed for both the heating and freezing processes. Rand estimates that a single 100,000-barrel-a-day operation would require a dedicated 1.2-gigawatt electricity generating station--a size that would be comparable to one of the nation's largest power plants, like the New Hampshire nuclear giant, Seabrook, which serves 900,000 customers."
To generate that power using the oil recovered form the project would probably require burning at each site 14,256 barrels per day. This leaves a net for each site of 85,744 barrels per day. To fuel the U.S. would require 319 of these. To fuel the world would require 958. 
Commentary: This supply is distributed undergound over a 16,000 square mile area. Liquid oil can flow to the pumping site. The proposal for shale oil is to drill and heat the rock while in the ground, then pump the oil as it separates from the rock. This only works of course in a limited around around the drill site, which must be moved (Redrilled). 
If shale oil had to meet 2005 U.S. annual use, with no increase in demand, the above best recovery estimate would fuel this country for 68 years. It could substitute for world (2005) use for 22 years. 
TAR SANDS
Canada has in its tar-sands an estimated 175 billion barrels of oil, spread out in locations the size of the State of Florida. 
These oilsands look and feel like molasses, and are found in bands 6 to 10 meters thick. Two tons of oilsands yield about 1.25 barrels of tar and a barrel of crude oil. However, if all planned development is put into operation, the expected peak flow rate is around 1.095 billion barrels per year. This rate would meet a grand total of 3.65% of world demand, for a period of 158 years. It would keep some governments in military vehicles, and the ultra rich in some toys, but if somehow processed fast enough to be humanities sole-source it would fuel "civilization" for about 5 years.
Despite difficulties in processing, under construction in 2005 was a 1,160 km pipelinle to carry the oil to the Canadian Pacific coast.
=== Bio-fuels ===
While manmade bio fuels meet or exceed fossil fuels in quality, they are impossible to produce in the quantity necessary to sustain the present infrastructure. 
In full page color ads (2006) Chevron tells us, "With current technology, one acre of soybeans yields 60 gallons of clean-burning biodiesel fuel". Yes, but with 2006 global use of fuel at 1.260 Trillion gallons, it would take 21 billion acres of soybeans to replace our fuel use. The world has 4.898 billion acres available. If all of the cropland was planted in soybeans, we might replace 23% of our annual fuel use, but no one would eat.
An early 2006 article in Mother Earth News on biodiesel presents an apparently optimistic view of biodiesel production. The article indicates that the United States has 6 million acres of cropland that are fallow, asserting that if all of this acreage was planted in rapeseed, it could conceivably annually provide 6 billion gallons of diesel fuel. 
Setting aside considerations of putting our last fallow cropland into use, let's put this amount of fuel into perspective. In barrels, this is 142 million barrels. Approximately 2 BILLION barrels per year are used in the U.S. in the food production industry. 
Therefore, the loss of every "spare" acre of farmland could replace perhaps 7% of the fuel used in farming and food processing.
There are, absent fossil fuels, means to sustainably obtain clean water, nutritional food, appropriate clothing and shelter, but not in sufficient quantities to sustain the present population, let alone provide any excess.
=== Abiotic theory ===
There are theories that oil is constantly being produced deep in the earth by reactions in the temperatures and pressures there, as opposed to being buried biological matter that grew in ancient sunlight. It may be true, but even if it is, the rate of production can't keep up with our annual use. If oil was being produced deep in the earth at the rate of 30 billion barrels per year, long ago the entire planet would have been oil.
=== The nuclear option ===
A nuclear fission reaction releases around 10 million times more energy than chemical processes. Current (2005) world uranium use is around 65,000 tonnes per year. with production of around 40,000 tonnes per year, the difference made up from drawn-down of stocks and the use of material from the Nuclear Weapons.
For the past decade (2006) prices have been low due to use of "old" material, which is expected to be exhausted by the middle of the next decade. The price of uranium was $23 per kg in early 2003, and $110 per kg in 2006. 
Uranium is not particularly rare. There is an estimated 40 trillion tonnes of Uranium in the Earth's crust. To date we have mined less than one ten-millionth of this. The relevant information though is what can be recovered using known technology. 
Estimates as of 2005:
Readily recoverable at around $130/kg is 4.7 million tones. If each 1 GW light water Nuclear Power Plant consumes 30 tonnes of fuel per year this "easy" to get uranium represents 157,000 reactor/years. Say we already have 441 (1006) in operation, so it's enough to keep them operating for 355 years.
If these reactors represent a continued output of 1 billion watt/hour through the year, then for example at 100% efficient conversion of oil to electricity that it would take around 5,280 of these reactors to replace our 2005 oil use. Then the "easy" uranium extends our present global energy use levels by 30 years.
There is potential for additional recoverable uranium of 35 million tones, for a total land based estimated available and useful supply of 39.7 million tons. If known supplies are all mined it could provide power for 1,300,000 GW/reactor years (each equal to burning 9000 tonnes of coal per day). In 2005 oil equivalent it represents energy for nearly 250 years. 
Good news. A nuclear plant may produce 93 times more energy than it consumes. Or put another way, the non-nuclear energy investment required to generate electricity for 40 years is repaid in 5 months. 
The oceans may represent a repository of a further 100 million tons, for another 600 or so years, IGNORING of course the energy & method to ensure every single ounce of the ocean passes thru the collection device, and the energy of isolating a microscopic quantity per ounce. 
In total, if uranium fission is used to meet energy demands equal to those at the turn of the millennium, it MIGHT provide power for 620 years. This timeframe of course must assume no increase in population, and no per person demand increase by anyone in the world. 
For an eventual future global population, if stabilized at 6.6 billion, and eventually all living at something like the U.S. level, the total uranium would last:
 Years of Power
Reliable Recovery 1.4
Questionable Recovery 11.9
Ocean Recovery 29.9
Total 43.2
Some emissions arise from the construction of the plant, the mining of the Uranium, the enrichment of the Uranium, its conversion into Nuclear Fuel, its final disposal and the final plant decommissioning. The total estimated emitted per KW-Hr is less than one hundredth the of Fossil-Fuel based generation.
The Chinese Nuclear Power Industry has contracts to build new plants of their design at capital cost reported to be $1500 per KW and $1300 per KW at sites in South-East and North-East China. The greatest growth (2006) in nuclear power is in China.
There is of course the concern over spent Nuclear Fuel (SNF), which is highly radioactive. The TransUranic component of SNF must be isolated from the environment for 100,000 years or more. The fission products typically reach background levels after 500 years.
There is research into "burning" the TransUranic's in either advanced reactors or accelerator driven subcritical assemblies, but this technology has not yet been developed to work on a large scale. 
The bad news. There is of course the small problem storing 39.7 MILLION TONS of highly radioactive waste for 100,000 years. The time "storage cost" of this waste we impose on our children is immense, for 200 or so years of power, a horribly short-term view.
=== The energy limit === 
Our readily available source of sustainable energy is solar. There is logically a maximum amount of solar energy that would be available to an Earthbound human society. Imagine we covered the entire surface of the Earth with solar panels (think Trantor in Asimov's stories, or Courasant (spelling) in Star Wars).
Every square yard of the surface of the Earth exposed perpendicular to full sun receives around 1kw of energy. A square mile contains roughly 3 million square yards. Using 10% efficient panels is represents AT BEST 300 megawatt of generation.
The Earth presents an 8,000 mile diameter disk to the sun. But remember, the world is not flat, is tilted relative to its orbit, and rotates. The further you are from the equator, the less sunlight per square meter of surface, therefore covering polar regions with solar panels would be impractical. To provide continued collection in the non-polar regions, the entire earth would need to be belted with panels. At any given moment though, probably a circle of 5,000 mile diameter or less would face the sun adequately for solar collection. Area = Pi x radius squared. With present solar panels (say 10% efficient), how much power could we intercept?
It's an area of 19,634,954 square miles exposed to the sun. It is 60,821,233,704,000 square yards, each intercepting, when not shaded by clouds, an average of something under 1 kilowatt. (For design/building purposes, remember the curve of the Earth. To expose a 5,000 wide area probably requires 7,500 mile wide be covered on the surface of the Earth.)
Assume half are shaded by clouds at any given time, so it's intercepting something under 30,410,616,852,000 kw. Readily available p/v panels are around 10% efficient, so we could expect to have 30,410,616,852 kw. 
Let's compare the energy to our oil use.
Recent annual oil use was 30 billion barrels, or 126 billion gallons.
A gallon of fuel has 144,000 BTU, equal to around 36.7 kwh.
If we use the array and the electrolysis process to obtain hydrogen from water, the best efficiency rate discussed is 50%, or that we must put in twice as much power as we gain back when we use the fuel.
Every hour the array operates is could produce hydrogen fuel equal in BTU's to around 414,313,581 gallons.
Operating 24 hours a day, say for 360 days a year on the average, it could produce 3,579,669,339,840 gallons. 
The good news is that such a global solar array could provide electrical energy and convert it to hydrogen fuel roughly equal to 28 times our recent annual oil use. 
Remember though, the bad news is that the surface of the planet is covered with solar panels, with essentially no open exposure to the sky, on land or on the sea. And of course, there's all the silicon for the panels, wire, metal, etc., exponentially beyond any supply of such materials we dream may be available to us. As touched on in an earlier comment on China and copper demand, there is probably not enough copper left to mine on Earth for this type of project.
To replace "just" our recent 30 billion barrels per year is an array constantly in the sun of 701,248 square miles. To have a five thousand mile wide swatch of constant sun at the equator equal this area, we would need a solid band of photovoltaic cells around the earth at least 140 miles wide, across oceans, mountains, etc. 
The "real world" power per facility footprint is of course NOT as good as the above. In 2005 Stirling Energy Systems started planning on a solar thermal generating facility for the desert in southern California. 
The facility, to generate 500 megawatt, will have a footprint of 6.25 square miles. (Roughly 19 million square yards.) This planned facility tops-out at 80 megawatt per square mile, vs the 300 of theoretical top using 10% panels. In a quick estimate, to expand this real-world facility to be large enough to replace our annual oil use would require a continuous band built around the equator of the Earth around 540 miles wide.
Geothermal appears to present an opportunity for a lot of energy, almost anyplace on Earth. It does. There is of course a limit, if you "cool" a large area under your generator; you may lose your heat. In the extreme you may change the physical characteristics under you site such that you generate earthquakes. Carried to extremes worldwide the cooling rock, cracking and contracting, could provide openings for water and air to seep downward.
The nuclear option. Present fission reactor fuel and technology provides a window of opportunity to provide concentrated, high electrical generation, for a limited period of time. At a cost. Reactors tend to have a lifespan of 50 years, after which the reactor must be taken apart and stored long term, as must the depleted fuel. As of 2006, no country on the Earth has put into place a permanent storage program. The U.S. has been debating about it's "Yucca Mountain" site for twenty years. If nuclear power expanded to one million megawatts, the waste produced would fill this discussed, but as of yet non-existent facility, every three years or so. 
Scientific American suggests thinking along the lines of what they call the "2,000 watt society", where they posit having available 2 kilowatt of power per person. They conclude that 2kw per person is technically feasible for an ongoing industrial society. 
Consider the U.S. 2006 energy picture:
 
 2006
 Data		 Overall	Transportation	Industrial	Residential Commercial	Electric Power
BBL/Equal	25 BBL Total		28.00%	22.00%	11.00%	39.00%
10	Oil	40.00%	11.200%	8.800%	4.400%	15.600%
5.75	Natural Gas	23.00%	6.440%	5.060%	2.530%	8.970%
5.75	Coal	23.00%	6.440%	5.060%	2.530%	8.970%
1.5	Renewables	6.00%	1.680%	1.320%	0.660%	2.340%
2	Nuclear	8.00%	2.240%	1.760%	0.880%	3.120%
		100.00%
28.00%
22.00%
11.00%
39.00%
 
What if the U.S. had to generate all of our power from solar photovoltaic’s? 
To put it in electrical terms - 
1 Barrel = 42 gallons. 1 gallon (roughly) = 144,000 BTU or 36,700 watthour.
25 billion barrels is roughly the electrical equivalent of 38,535,000,000,000,000 watthour.
Readily available (limited quantity) photovoltaic panels are 10% efficient in converting sunlight to electricity, such that for every hour that a square yard of such panels are in direct sunlight, 100 watthour of electricity is generated. 
We can guess it’s going to take a large array.
Let’s say the average daily solar exposure of our array is six hours of sun, with a further adjustment of 50% of the array being in shade, dirty, undergoing work, etc. Also assume an optimistic total “loss” of only 5 days of sun per year. (Thinking of the author’s residence state of Arizona)
How large does such an array need to be to generate 38,535,000,000,000,000 watthour?
38,535,000,000,000,000
Divided by six (hours per day)
6,422,500,000,000,000.00
Divided by 360 (days operation per year)
17,840,277,777,777.80
Divided by 50% (adjust for various blockages and partial downtime)
35,680,555,555,555.60 
Divided by 100 (watts generated per square yard)
356,805,555,555.56 number of square yards of collector
Divided by 3,097,600 (square yards in a square mile)
115,187.74 square miles of photovoltaic panels, 
or an area say 340 miles on a side
Then the “hydrogen economy” arguments want to use the electrical power to electrolyze water to replace 10 billion barrels of portable fuel. If we really want to do so, what is the efficiency LOSS in splitting water? In labs it is 50%. In the 2005 Department of Energy "Solar Decathlon" competition the New York Institute of Technology found their hydrogen fuel cell power storage approach didn't reach the 25% efficiency they hoped, vs 80% for lead-acid batteries. If you really wanted to use the array to split hydrogen from water, 40% of the array would need to be at least four times the size. The total array would need to completely cover 253,413 square miles, or an area 504 miles on a side. 
An obvious point must be the engineering challenge of constructing over 250,000 square miles of photovoltaic material, and the applicable mounting frames. If such is to be a stand-alone array, envision the response from environmentalists regardless of where you wanted to place it.
A complete coverage approach ignores though that current p/v panels lose generation efficiency when much off from being perpendicular to sunlight. In other words the panels must be able to track the sun. To track the sun, there must be space between the panels.
As touched on elsewhere, if each device was just fixed re seasons, say at 30 degrees, there is still a minimum of 1/2 of the collector panel width between each device on the north/south axis to avoid shading. So to be able to optimize panel exposure, each 1 square yard panel needs a ground footprint of 9' x 9' or 81 square feet.
To incorporate tracking, the area of the array must as an example be NINE TIMES the area of the actual p/v panels. This calculates out to be 2,280,717.25 square miles, or a square area 1,510 miles on a side. If you want to keep it inside the U.S., and in the lower latitudes, it will not fit. It will not fit within the continental U.S.
At the moment, the bulk of the energy being used in the United States is being purchased and used by the private sector. The cumulative cost of the array, if say each 100 watt unit costs only $500, is $178,402,777,777,778.00. That is $178 TRILLION (With a “T”). 
Putting photovoltaic panels where the demand is does not necessarily work. In higher latitudes, in overcast climates, etc., the power generated would not be worth the effort or cost. There may not be a lot of time left to implement some functional alternative.
Chapter II - Physical Sustainability Factors and Limitations - 2
category:Sustainable Civilization