James:
Just a quick observation about the wisdom of sheltering in a missile base or some other Cold War-era fortification. While Chris is correct that history demonstrates that fortifications can and will be breached by enemy forces with the resources and determination to maintain a well-conceived siege, I question whether after TEOTWAWKI the marauders most likely to be challenging such a retreat will have the resources to see a siege through to a successful conclusion.
Presumably, the scarcity of resources is precisely what would make a fortress such an inviting target. Unlike the armies that successfully overran ancient fortifications, there is little hope of people armed only with conventional weapons successfully breaching the walls or blast doors of a structure designed to withstand anything but a direct hit from a sizable nuclear warhead. Additionally, the barbarian hordes in a post-collapse scenario will not have the luxury of sitting in place indefinitely, waiting for those hunkered inside such a bunker to exhaust their own resources. Unless a well-organized and well-armed assault force happens to catch the owners of the fortress completely unprepared, I think that even taking into account the risks of living underground for prolonged periods these sorts of shelters offer the highest degree of security for their owners after TSHTF.
Keep up the great work, – D.
Dear Editor:
Ah, so sorry to sound the defeatist, but the self-sufficiency plans outlined in the recently-posted article by “Chris” would not stand up to scientific scrutiny by folks that actually work with closed-cycle environments.
(A) The article refers to producing methane for power by “dissolving” milkweed in water, and even accelerating the breakdown by immersing the milkweed in salt water and running a current through it.
In point of fact, merely “dissolving” milkweed will not produce methane. Methane is produced by the decomposition and fermentation of organic matter. Said decomposition requires a number of things: (1) a warm, moist environment, (2) a low oxygen content in the biomass being fermented, (3) one or more bacterial cultures that decompose biomass – these are usually found in moist, or semisolid matter, not a salt-water solution. Decomposition bacteria do *really* poorly in salt water. It’s the reason “salt-curing” is the preservation method of choice for meat in the absence of refrigeration.
One must also ask, if the milkweed is being fermented for methane to generate power, where is the electricity coming from that would be passed through the saltwater solution to supposedly accelerate the dissolution of the milkweed? Hmm? It would be a good idea to *produce* more power than one must consume in the production of the power.
Certainly it would be possible to produce methane from compost, and that would be a good means of providing an emergency fuel source and heat source in cold weather. However for power generation, if we assume that the author is thinking of using a methane-fueled internal combustion engine connected to an alternator, it is first necessary to *compress* the methane. One kilogram of solid waste subjected to anaerobic fermentation will produce about 120 liters of methane – a year. A natural gas (i.e. methane) fueled generator producing 5000 watts (a very small home – just enough for lights, a fan and one small refrigerator – uses approximately 2 kg of methane per hour. Methane weighs about 2 kg per cubic meter, so the 120 liters of methane produced as above would weigh about 0.02 kg. To keep a methane-powered generator going for a single 24-hour day would require 2400 kg of compost, and could only run the generator for one day out of 365. Continuous operation would require a compost pit containing >800,000 kg of compost. Nearly a thousand metric tons of fermenting waste would hardly count as inconspicuous.
Then there’s that compression problem again. Absent a compressed methane supply, the only possible means of power generation would be external combustion of the methane in an open flame and boiling water. All of which presumes that sufficient methane can be collected from a compost pit the size a small town and transported to the burner, but alas, that would also require some means of *pushing* the methane into the pipes leading to the burner. This means fans or pumps, and like compressing the methane or electrifying salt water, would waste the very power being generated.
(B) Next the article turns to air and water filtration, and is on its strongest foundation. It is true that algae are a great technique for scrubbing the air of excess CO2 and enriching it with oxygen. This is the stuff of which long-duration space flight is made. Better yet, algae is biomass, and can be composted for methane! However, there are still many issues with the *implementation* of this plan. First, algae consume CO2 and produce O2 during the day, but a little acknowledged fact is that *all* plants consume O2 and produce CO2 at night when chlorophyll is deprived of the sunlight required to power photosynthesis. The efficiency of this cycle is about 2:1 given 12 hrs day and 12 hrs night. Thus for every two liters of O2 produced during daylight, one liter will be consumed the following night. Unless the algae is grown under artificial sunlight lamps – but there’s that pesky problem again of consuming all of the power in the process of generating the fuel to generate the power…
However, what is the efficiency of algae-based air “freshening”? One can assume that it is not entirely necessary to produce *all* of the breathable air. Certainly *some* air will be derived from the outside unless it is completely contaminated with fallout, biological weapons or zombie virus. For the sake of argument, let’s say we need to produce enough breathable air for a single person each day. That way one person can be completely sealed into the bunker, or additional people can be supported by supplementing with outside air. A single adult male runs about 20,000 liters through their lungs each day. That’s 16 one-liter breaths per minute. About 1000 liters of O2 are consumed and 1000 liters of CO2 exhaled. That’s between 0.03 and 0.05 kg of each per day, or 15-20 kg/year. One square meter of algae will consume about 10 kg of CO2 per year and produce about 8 kg of O2, assuming the ideal light and temperature. So, two square meters of algae under artificial sunlight, with flowing water in the tank, plenty of nutrients on the water – oh, and plenty of water – will likely scrub the air of excess CO2 and enrich it with O2. But there’s still that pesky problem of power to operate the lights and pumps, and the fact that while algae will enrich the air, this is still a far cry from filtering it, and any biological or radiological contaminants that need to be filtered out lest they kill the inhabitants of the bunker would also kill the algae. Not to mention what to do with the excess biomass of algae that needs to be skimmed from the tank weekly – add it to the 5 square mile compost farm, probably.
It should be pointed out at this point that there *are* industrial and systems for not only reducing CO2 and producing breathable air, but also turning algae and yeast into biofuels. They are called bioreactors, and work at very high densities. Efficient units are quite large and small units take days to weeks to produce enough fuel to power a vehicle or generator for a few hours. Finally, the inconvenient truth of renewable fuels is that it takes power to make power (fuel). Bioreactors require *almost* as much energy as they produce just to operate the lights, fans, pumps, stirrers and cooling systems. They have been proposed mainly as a way of reducing industrial waste CO2 or to convert grid-supply electricity into portable fuels for cars and trucks. While such systems have been considered for arcologies, Mars missions and orbital facilities, it is primarily because they can tap into the abundant electrical power produced by the nuclear and next generation solar power plants proposed for those installations.
(C) So what’s this about using a Tesla coil for water filtration? A Tesla coil? Seriously? A TESLA COIL? No.
[JWR Adds: I believe he was referring to using a Tesla coil to generate ozone, and to use that to purify water. That can work, but the power requirements are considerable. A simple ultraviolet light (like those use by koi pond enthusiasts) works just as well, and uses just a tiny fraction of the electricity. ]
First – where does the power come from to generate the electricity output by the Tesla coil? The piddly little 5000 watt methane-powered generator wouldn’t even power a Tesla coil enough to raise the hair on your forearm even after rubbing it with a cat for an hour. Tesla coils used for those fancy demonstrations are usually powered by industrial generators providing 50-100 kilowatts of electricity. Powering that will take a compost heap the size of Rhode Island.
Second, electricity kills living cells. That’s clearly the idea behind using electricity for “filtering” the water. Unfortunately those algae above are living cells. Run the electricity through the algae tank and there goes the air supply. One could argue that the Tesla coil will be “downstream” from the algae tank, and not directly in contact. Still, the insidious thing about electricity is that it tends to short to ground through water – if there is *any* possible connection – such as through the water pipes, the algae will get electrocuted. Not to mention the sad end for a person that survives civil collapse and retreats to a hidden bunker only to be electrocuted the first time he reaches for the water tap.
Third, did I mention that Tesla coils consume *power*?
(C) Waste treatment. Recycling and recapturing useful compounds out of liquid and solid waste is an excellent idea. Set up the filters, composters and separators. Unfortunately I see no provision for disinfecting the waste. See, urine and feces do not just decompose on their own without help. Community wastewater treatment plants ferment semisolid waste using specific bacterial cultures. Solid wastes *are* compressed and either used as fertilizer or burned for fuel. However, before either can happen, they must be sterilized. A considerable amount of the “bulk” of solid human waste is live and dead bacteria. Of those, the most common danger is e. coli. Without even getting into the problems of typhus and diphtheria which come from food and water supplies contaminated by human wastes – or salmonella which comes from animal wastes – e. coli is particularly hazardous because it is so common. The human body has a number of defense mechanisms for dealing with e. coli – at least in the regions where it is most commonly encountered – skin, groin, etc. But e. coli in the mouth, eyes, ears or nose can cause serious infections that can cause cannot be easily treated, and if untreated can cause death. As for performing the waste treatment in airtight containers, sorry, but no. Unlike composting, which is an *anaerobic* process, waste decomposition is an *aerobic* process. The reason for this is precisely because the most hazardous of the waste-borne bacteria thrive in low-oxygen situations. The reason wastewater treatment plants constantly stir waste in huge tanks is to ensure that the material stays oxygenated to reduce the growth of infectious bacteria. Better to dig a latrine pit, fill it with lime, and lose out on recycling than to have a waste system that kills the user by virtue of insufficient sanitation. Again, as with all of the concepts presented here, it can be dome properly, but the proper means involve a sufficiency of power, air, water and space.
(D) Finally, the author references the “very negative biological effects” of deep underground environments on the human body.. From this it can be assumed that the author is referring to experiments where individuals have lived underground or in sealed environments for extended periods. Yet, aside from lack of sunlight and exercise, the primary effect of living underground is not necessarily detrimental to humans. What mainly happens is that in the absence of a defined day-night cycle, the human body makes up its own. Without a sunlight-induced 24-hr clock, the human body will fall into a natural 26-29 hour day. As long as the subject remains isolated from the outside world, this cycle will continue, remarkably stable, and fully functional, not at all detrimental to health. However, even a small dose of sunlight each day will set up a conflict between the external and internal clocks. Insomnia and sleep disruption can occur until the subject is fully immersed in either the outside or inside environment. Other problems with living underground have been more due to temperature, humidity, molds and air contaminants than merely the fact of being underground.
To summarize, the concepts presented in this article are not practical. They are the result of looking at some popular ideas in the press without considering the real world implications, or even carefully working through the biology, chemistry or physics of the problem. Other “neat ideas” and exercises of the imagination are more appropriate to cartoon or fiction than a serious blog about practical survival. It is one thing to sit and ponder ideas on the basis of “wouldn’t it be interesting if this worked?” and another to consider how likely the idea will result in sickness, malnutrition, disease and death. None of the idea presented here would even meet the authors first stated intent, to live in seclusion – in secret – with none of the ravening hordes aware of the authors existence. Each idea would require *space* that a secret hide-away could never afford, *power* that could never be generated, *resources* that would be obviously diverted away from public view and into the hide, and *emissions* of noise, heat and effluent that would certainly call attention to such a secret base.
Sincerely, Dr. T.R., B.S. (Biology/Chemistry), M.S. (Aquatic Biology), Ph.D. (Physiology/Pharmacology)