Thursday, March 29, 2012

Biological Threat: Anthrax

This is a U.S. Army presentation about the dangers of weaponized anthrax attack. The video was produced in 1999; two years before the 2001 anthrax attacks in the US. The specter of a possible anthrax attack is not a pleasant subject to consider, but it has happened both in the US and in Russia. The incident in Russia was actually not an attack but an accidental release of weaponized anthrax from a Russian military base, resulting in the deaths of approximately 100 civilians due to anthrax inhalation. That in itself is proof that this is a threat we should take seriously.

Saturday, March 24, 2012

Safe Rooms for Tornado Protection

This is a FEMA educational film discussing in-home safe rooms as a means of protecting occupants against tornado hazards. It covers factory-built and do-it-yourself safe rooms for both new construction and existing homes. This is a topic that is on a lot of people's minds lately, because of the tornadoes we saw last year and have already seen this year. Living where I do, this subject has always been of concern for me. I witnessed the destruction of the 1974 tornado outbreak and several other tornadoes, and have personally known people who lost their homes and even loved ones to tornadoes; so I do not take this threat lightly.

Wednesday, March 21, 2012

Frugal Air Conditioning for Offgrid and RV Living

Right about now is when air conditioning begins to feel like a necessity, at least in hotter areas. But what to do if you're offgrid or camp fulltime in an RV and are on a tight budget? A few solar panels aren't going to power air conditioners. An offgrid diesel generator will, but running it fulltime is expensive, even on diy biodiesel. Of course, there are a lot of things you can do to reduce your need for a/c, such as ventilation, shading, a reflective roof on your domicile (mobile or not), routing any heat produced by appliances (including a refrigerator) outdoors etc. and we should definitely be doing all those things, but it's nice to be able to sleep in air conditioning. So I am going to cover just that, while spending the minimum amount of money.


First of all, you need to minimize the area you need to cool. If it's so hot and humid that you have trouble resting, you don't necessarily have to cool an entire house. Ventilate it, yes. Make it as cool as possible. But the main thing we are concerned about is a sleeping area, and perhaps a cool area to spend the hottest part of the day. So in a house, you should close off the bedroom and concentrate on cooling it. Of course if you are vandwelling that is a moot point, because you are already in a small space.

Second, you will need a power source, including a generator, battery bank and inverter. Fortunately, inverters have dropped in price enough that one capable of running the smallest air conditioner is no longer very expensive. A 2500 watt inverter can be had for under $500 nowadays, and that will be sufficient to run a 5000 btu window unit a/c while also running a couple of efficient lights, a TV/DVD combo or computer, and even a small microwave oven as long as you make sure the compressor in the a/c doesn't cycle on while the microwave is running. Now, 500 bucks may not sound very cheap but it is, compared to what a 2500 watt inverter cost just a few years ago! BTW, a modified sine wave inverter will work just fine; you don't need to spring for the high-dollar pure sine wave inverters.

On to the battery bank. This is the biggie; the one you can't scrimp on too much. You're probably not gonna want to run your genny overnight, so that means ya gotta have enough battery capacity to carry the load overnight. A small a/c is gonna draw
about 6 amps of 115 volt "wall power" so that means about 60 amps of 12 volt battery power going into your inverter. BTW, that can surge to triple the running amperage on startup, which is why you need such a big inverter. Now, 60 amps times say 8
hours is 480 amp/hours battery capacity needed to carry the load overnight. For comparison, a 12 volt marine deep-cycle battery has a capacity of maybe 100 amp/hours so you would need about 5 of those puppies. But wait; you can't run those
batteries all the way down every night or you would have to replace them very soon! Besides, what if you want to sleep late or you would like to run a coffeemaker in the morning, before having to mess with that generator?
You really should only run your battery bank down to 50% on a regular basis; 80% is even better but we ARE on a budget here.

While we're at it, let's get better batteries than the typical marine battery. The best deal for offgrid folks on a budget is the golf cart battery. Trojan T105 is the industry standard here; they are much better than marine batteries while costing
about the same. The T105 is 6 volts, like other golf cart batteries, so will have to be paired in series for 12 volts. This battery is 220 amp/hours; two of them in series will still be 220 amp/hours but at 12 volts. Four pairs connected in parallel
will be 880 amp/hours, now we're getting somewhere! This battery bank still won't be too heavy for your house-on-wheels to carry (about 500 pounds), nor too expensive, nor too bulky to find a place to store it.
But it's a big enough battery bank to shut down that genny at a reasonable hour, stay up watching TV for quite awhile, run the a/c overnight, and still run the coffeemaker and maybe even the microwave in the morning, without beating down the
batteries too badly.

Now, what kind of air conditioner do I need? A NEW one, for one thing. I have measured the amperage draw of old vs. new, and the new air conditioners definitely draw less current for a given btu rating than do the old ones. Second, a SMALL one. The cheap, 5000
btu, manual control unit is exactly what you need for offgrid living. If it isn't doing the job, you need to make the area you are cooling smaller, insulate it better, or both. If you have a big enough generator and are living in a house, by all means buy a second, larger air conditioner to cool the whole house during the day while the genny is running, if you want to and can afford it. But for overnight running, you need the minimum amp draw of a small unit. Oh, and by the way, don't bother with the "low" setting on that little air conditioner: I measured the amp draw, and it doesn't make it use any less power.

That brings us to the (next to) last item on the list, and believe it or not, the most flexible: the generator. You DON'T need a honkin' 20 kw genny for this usage! In fact, you can get by minimally on one of those 2-cycle, 1000 watt portable
jobs you can buy for just over $100; in fact, I have added a link to one of those if you are interested. Actually, one of those makes a good backup even if you have a bigger genny. A genny that small probably won't directly run the air conditioner, but what we're gonna do here is buy the biggest battery charger you can find (which is the last item on the list); the standard manual 40 amp continuous charger that all auto parts stores and most big-box stores carry will be the minimum. Not the one that says 40 or 50 amp engine start; if this one has an engine start function it will be 200 amps or so, but we're not gonna use it in that mode. You will need this regardless of which generator you buy, unless you buy one of the high-dollar inverters that have a built-in 100 amp or so charger.
That 40 amp battery charger will be just about a 50-75% load on one of the 1000-1200 watt generators; an efficient range to run any generator in. That means you won't be able to run much else at the same time. Maybe a small refrigerator. If you expect to be able to run the a/c and other loads while charging your batteries, you will need at least a 3000 watt generator. It is highly unlikely that you will need more than 5000 watts.
If you can get a diesel generator, by all means do so. You will probably want to eventually anyway, if you stick with the offgrid lifestyle for long. Diesels are indeed more fuel-efficient. But don't be fooled by what some folks say about the efficiency of a gasoline genny; for this
type of use one of the small ones will run 3-5 hours per gallon of gas. You will probably be using about 2 gallons per day
during the hot season.

The Economics of Tide Laundry Detergent



Laundered Money
by Joseph T. Salerno

Under cover of its multiplicity of fabricated wars on drugs, terror, tax evasion, and organized crime, the US government has long been waging a hidden war on cash. One symptom of the war is that the largest denomination of US currency is the $100 note, whose ever-eroding purchasing power is far below the purchasing power of the €500 note. US currency used to be issued in denominations running up $5,000 notes). There was even a $100,000 note issued for transactions among Federal Reserve banks. The United States stopped printing large denomination notes in 1945 and officially discontinued their issuance in 1969, when the Fed began removing them from circulation. Since then the largest currency note available to the general public has a face value of $100. But since 1969, the inflationary monetary policy of the Fed has caused the US dollar to depreciate by over 80 percent, so that a $100 note in 2010 possessed a purchasing power of only $16.83 in 1969 dollars. That is less purchasing power than a $20 bill in 1969!
Despite this enormous depreciation, the Federal Reserve has steadfastly refused to issue notes of larger denomination. This has made large cash transactions extremely inconvenient and has forced the American public to make much greater use than is optimal of electronic-payment methods. Of course, this is precisely the intent of the US government. The purpose of its ongoing breach of long-established laws regarding financial privacy is to make it easier to monitor the economic affairs and abrogate the financial privacy of its citizens, ostensibly to secure their safety from Colombian drug lords, Al Qaeda operatives, and tax cheats and other nefarious white-collar criminals
Now the war on cash has begun to spread to other countries. As reported a few months ago, Italy lowered the legal maximum on cash transactions from €2,500 to €1,000. The Italian government would have preferred to set a €500 or even €300 maximum limit but reasoned that it should permit Italians time to adjust to the new limit. The rationale for this limit on the size of cash transactions is the fact that the profligate Italian government is trying to reduce its €1.9 trillion debt and views its anticash measures as a means of cracking down on tax evasion, which "costs" the government an estimated €150 billion annually.
The profligacy of the Italian ruling class is in sharp contrast to ordinary Italians who are the least indebted consumers in the eurozone and among its biggest savers. They use their credit cards very infrequently compared to citizens of other eurozone nations. So deeply ingrained is cash in the Italian culture that over 7.5 million Italians do not even have checking accounts. Now most of these "bankless" Italians will be dragooned into the banking system so that the notoriously corrupt Italian government can more easily spy on them and invade their financial privacy. Of course Italian banks, which charge 2 percent on credit-card transactions and assess fees on current accounts, stand to earn an enormous windfall from this law. As controversial former prime minister Berlusconi noted, "There's a real danger of crossing over into a fiscal police state." Indeed, one only need look at the United States today to see what lies in store for Italian citizens.
Meanwhile the war on cash in Sweden is accelerating, although the involvement of the state is less overt. In Swedish cities, cash is no longer acceptable on public buses; tickets must be purchased in advance or via a cell-phone text message. Many small businesses refuse cash, and some bank facilities have completely stopped handling cash. Indeed in some Swedish towns it is no longer possible to use cash in a bank at all. Even churches have begun to facilitate electronic donations from their congregations by installing electronic card readers. Cash transactions represent only 3 percent of the Swedish economy, while they account for 9 percent of the eurozone and 7 percent of the US economies.
A leading proponent of the anticash movement is none other than Bjorn Ulvaeus, former member of the pop group ABBA. The dotty pop star, whose son has been robbed three times, believes that a cashless world means greater security for the public! Others, more perceptive than Ulvaeus, point to another alleged advantage of electronic transactions: they leave a digital trail that can be readily followed by the state. Thus, unlike countries with a strong "cash culture" like Greece and Italy, Sweden has a much lower incidence of graft. As one "expert" on underground economies instructs us, "If people use more cards, they are less involved in shadowy economy activities," in other words, secreting their hard-earned income in places where it cannot be plundered by the state.


The deputy governor of the Swedish central bank, Lars Nyberg, gloated before his retirement last year that cash will survive "like the crocodile, even though it may be forced to see its habitat gradually cut back." But not everyone in Sweden is celebrating the dethronement of cash. The chairman of Sweden's National Pensioners' Organization argues that elderly people in rural areas either do not have credit or debit cards or do not know how to use them to withdraw cash. Oscar Swartz, the founder of Sweden's first Internet provider, a supporter of the phasing out of cash, argues that without the adoption of anonymous payment methods, people who send money and make donations to various organizations can be "traced every time." But, of course, what the artless Mr. Swartz does not see is that this is the whole point of a cashless economy – to make even the most intimate economic affairs of private citizens transparent to the state and its fiscal and monetary apparatchiks, who themselves hate and fear transparency like vampires do sunlight. And then there are the benefits that accrue to the government-privileged banking system from the demise of cash. One Swedish small businessman shrewdly noted the connection. While he gets charged 5 kronor (80¢) for every credit-card transaction, he is prevented by law from passing this on to his customers. In his words, "For them (the banks), this is a very good way to earn a lot of money, that's what it's all about. They make huge profits."
Fortunately, the free market provides the prospect of an escape from the fiscal police state that seeks to stamp out the use of cash through either depreciation of central-bank-issued currency combined with unchanged currency denominations or direct legal limitation on the size of cash transactions. As Carl Menger, the founder of the Austrian School of economics, explained over 140 years ago, money emerges not by government decree but through a market process driven by the actions of individuals who are continually seeking a means to accomplish their goals through exchange most efficiently. Every so often history offers up another example that illustrates Menger's point. The use of sheep, bottled water, and cigarettes as media of exchange in Iraqi rural villages after the US invasion and collapse of the dinar is one recent example. Another example was Argentina after the collapse of the peso, when grain contracts (for wheat, soybeans, corn, and sorghum) priced in dollars were regularly exchanged for big-ticket items like automobiles, trucks, and farm equipment. In fact Argentine farmers began hoarding grain in silos to substitute for holding cash balances in the form of depreciating pesos.
As has been widely reported recently, an unlikely crime wave has rapidly spread throughout the United States and has taken local law-enforcement officials by surprise. The theft of Tide liquid laundry detergent is pandemic throughout cities in the United States. One individual alone stole $25,000 worth of Tide detergent during a 15-month crime spree, and large retailers are taking special security measures to protect their inventories of Tide. For example, CVS is locking down Tide alongside commonly stolen items like flu medications. Liquid Tide retails for $10–$20 per bottle and sells on the black market for $5–$10. Individual bottles of Tide bear no serial numbers, making them impossible to track. So some enterprising thieves operate as arbitrageurs buying at the black-market price and reselling to the stores, presumably at the wholesale price. Even more puzzling is the fact that no other brand of detergent has been targeted.

What gives here? This is just another confirmation of Menger's insight that the market responds to the absence of sound money by monetizing highly salable commodities. It is clear that Tide has emerged as a subsidiary local currency for black-market, especially drug, transactions – but for legal transactions in low-income areas as well. Indeed police report that Tide is being exchanged for heroin and methamphetamine and that drug dealers possess inventories of the commodity that they are also willing to sell. But why is laundry detergent being employed as money, and why Tide in particular?
Menger identified the qualities that a commodity must possess in order to evolve into a medium of exchange. Tide possesses most of these qualities in ample measure. For a commodity to emerge as money out of barter, it must be widely used, readily recognizable, and durable. It must also have a relatively high value-to-weight ratio so that it can be easily transported. Tide is the most popular brand of laundry detergent and is widely used by all socioeconomic groups. Tide also is easily recognized because of its Day-Glo orange logo. Laundry detergent can also be stored for long periods without loss of potency or quality. It is true that Tide is somewhat bulky and inconvenient to transport by hand in large quantities. But enough can be carried by hand or shopping cart for smaller transactions while large quantities can easily be transported and transferred using automobiles.
Just like the highly publicized war on drugs that the US government has been waging – and losing – for decades, it is doomed to lose its surreptitious war on cash, because the free market can and will respond to the demand of ordinary citizens for a reliable and convenient money.





March 21, 2012
Joseph Salerno [send him mail] is academic vice president of the Mises Institute, chairman of the graduate program in economics at Pace University, and editor of the Quarterly Journal of Austrian Economics.




Saturday, March 17, 2012

How To Bug In: FEMA Instructional Video

You may remember the advice by FEMA, during the 2001 anthrax scare, to stock up on duct tape and plastic sheeting. Jokes notwithstanding, FEMA did actually produce public service videos to instruct citizens in the use of those and other survival items in the event of a biological or chemical emergency, whether accidental or as a result of enemy action. This is one such video which FEMA distributed in 2002 to residents of Oak Ridge, Tennessee; home of the Oak Ridge National Laboratory and historical home of the Manhattan Project. It specifically addresses a scenario involving a chemical accident, but the information could also be useful in the case of a biological event such as disease outbreak or, especially, biological attack.

Thursday, March 15, 2012

Nuclear Weapon Effects on People And Property

This is "Operation Cue," a US government atomic bomb test from 1955. The test was conducted in Nevada with a real nuclear weapon, and used houses of differing construction, canned goods, a large propane tank, and test dummies to measure the extent of damage caused by the initial blast. This film is in the public domain.

Tuesday, March 6, 2012

Back-Feeding Electrical Panels

Back-feeding refers to the controversial practice of shutting off the main breaker in an electrical panel to isolate the panel from the utility grid, followed by feeding the output of a generator into a secondary circuit (for example, the clothes dryer circuit). Note that I do not recommend this practice, and specifically disavow any responsibility should you decide to do so. In fact, it very well may be illegal in your area to backfeed the service entrance panel. I received an email from a man in the UK noting that it is a felony in his country to tamper with the electrical system. My purpose here is to offer some safety tips that are applicable to any usage of a backup generator, regardless of how the user goes about connecting it. If you decide that you are going to use a generator during power outages, whether you use extension cords, a transfer switch or any other method, here is what I recommend:
Make a plan on paper detailing a safe way to use your generator. Do this when everything is normal, not during a power outage. Make a list of exactly what equipment or circuits you will need to power, equipment (such as a larger gauge extension cord, for example) you will need to do so safely, and which circuits will need to be switched off before you do anything else. Buy any equipment you will need to do the job safely, and store it in a permanent location where you can always find it when you need it. Right beside the generator would probably be a good place. Add a flashlight with fresh batteries, gloves, any tools you may need, etc. so you are not having to cobble something up or chase down needed supplies during a power outage.
Now for a very important part: make a checklist. Think about it, do the math pertaining to loads, load balancing and wire sizes, and decide upon the safest order of the steps that need to be done. Make a second checklist for returning to normal after the public power is restored.
Now, keep that checklist where you can access it every time you need to run the generator. No matter how well you know what you are doing, follow the checklist and check the steps off as you complete them. Also add notes to the checklist about anything noteworthy: problems, ideas on how to do it more safely and efficiently, etc. You should be referring to the checklist every single time you ever run the generator, making notes and revising the checklist after the event is over.
That is the safe way to do any complex task. And it is a lot easier than stumbling around, trying to decide what to do in the midst of a power outage.

Related post: How I Connect My Generator To The House

Monday, March 5, 2012

Induction Generators


Induction generator

From Wikipedia, the free encyclopedia

An induction generator or asynchronous generator is a type of AC electrical generator that uses the principles of induction motors to produce power. Induction generators operate by mechanically turning their rotor in generator mode, giving negative slip. In most cases, a regular AC asynchronous motor is used as a generator, without any internal modifications.

Principle of operation

Induction generators and motors produce electrical power when their rotor is turned faster than the synchronous frequency. For a typical four-pole motor (two pairs of poles on stator) operating on a 60 Hz electrical grid, synchronous speed is 1800 rotations per minute. The same four-pole motor operating on a 50 Hz grid will have a synchronous speed of 1500 RPM.
In normal motor operation, stator flux rotation is faster than the rotor rotation. This causes the stator flux to induce rotor currents, which create a rotor flux with magnetic polarity opposite to stator. In this way, the rotor is dragged along behind stator flux, at a value equal to the slip.
In generator operation, a prime mover (turbine, engine) drives the rotor above the synchronous speed. The stator flux still induces currents in the rotor, but since the opposing rotor flux is now cutting the stator coils, an active current is produced in stator coils, and the motor now operates as a generator, sending power back to the electrical grid

Excitation


Equivalent circuit of induction generator
Note that a source of excitation current for magnetizing flux (reactive power) for stator is still required, to induce rotor current.
Induction generators are not, in general, self-exciting, meaning they require an electrical supply, at least initially, to produce the rotating magnetic flux (although in practice an induction generator will often self start due to residual magnetism.) The electrical supply can be supplied from the electrical grid or, once it starts producing power, from the generator itself. The rotating magnetic flux from the stator induces currents in the rotor, which also produces a magnetic field. If the rotor turns slower than the rate of the rotating flux, the machine acts like an induction motor. If the rotor is turned faster, it acts like a generator, producing power at the synchronous frequency.

Active power

Active power delivered to the line is proportional to slip above the synchronous speed. Full rated power of the generator is reached at very small slip values (motor dependent, typically 3%). At synchronous speed of 1800 rpm, generator will produce no power. When the driving speed is increased to 1860 rpm, full output power is produced. If the prime mover is unable to produce enough power to fully drive the generator, speed will remain somewhere between 1800 and 1860 rpm range.

Required capacitance

A capacitor bank must supply reactive power to the motor when used in stand-alone mode. The reactive power supplied should be equal or greater than the reactive power that the machine normally draws when operating as a motor. Terminal voltage will increase with capacitance, but is limited by iron saturation.

Grid and stand-alone connections


Typical connections when used as a standalone generator
In induction generators the magnetizing flux is established by a capacitor bank connected to the machine in case of stand alone system and in case of grid connection it draws magnetizing current from the grid.
For a grid connected system, frequency and voltage at the machine will be dictated by the electric grid, since it is very small compared to the whole system.
For stand-alone systems, frequency and voltage are complex function of machine parameters, capacitance used for excitation, and load value and type.

Use of induction generators

Induction generators are often used in wind turbines and some micro hydro installations due to their ability to produce useful power at varying rotor speeds. Induction generators are mechanically and electrically simpler than other generator types. They are also more rugged, requiring no brushes or commutators.
Induction generators are particularly suitable and usually used for wind generating stations as in this case speed is always a variable factor, and the generator is easy on the gearbox.

Example application

We must use 10 hp, 1760 r/min, 440 V, 3 phase induction motor as an asynchronous generator. Full-load current of the motor is 10 A and full-load power factor is 0.8.
Required capacitance per phase if capacitors are connected in delta:
Apparent power S = √3 E I = 1.73 * 440 * 10 = 7612 VA
Active power P = S cos θ = 7612 * 0.8 = 6090 W
Reactive power Q = \sqrt{S^2-P^2} = 4567 VAR
For machine to run as an asynchronous generator, capacitor bank must supply minimum 4567 / 3 phases = 1523 VAR per phase. Voltage per capacitor is 440 V because capacitors are connected in delta.
Capacitive current Ic = Q/E = 1523/440 = 3.46 A
Capacitive reactance per phase Xc = E/I = 127 Ω
Minimum capacitance per phase:
C = 1 / (2*π*f*Xc) = 1 / (2 * 3.141 * 60 * 127) = 21 microfarads.
If load also absorbs reactive power, capacitor bank must be increased in size to compensate.
Prime mover speed should be used to generate frequency of 60 Hz:
Typically, slip should be similar to full-load value when machine is running as motor, but negative (generator operation):
Slip = 1800 - 1760 = 40 rpm
Required prime mover speed N = 1800 + Slip = 1840 rpm.

References

  • Electrical Machines, Drives, and Power Systems, 4th edition, Theodore Wildi, Prentice Hall, ISBN 0-13-082460-7, pages 311-314.

External links


Related posts: Generator From Electric Motor Induction Generator Load Test