Self-Sufficiency is a wonderful goal. However, extremely few people
(yet) seem to approach it appropriately! Some have a hobbyist attitude,
of buying or making small devices which will never possibly pay for
themselves or otherwise provide any actual value. Others spend spectacular
amounts of money for the most recently promoted solar or wind
products, probably because the salesperson was a persuasive talker!
Eventually, it is important to develop a more focused approach, and
this presentation and assorted linked web-pages hope to be helpful
regarding accomplishing that.|
Most companies that try to market alternative energy products tend to focus on ultra-high-tech devices and concepts. I guess they see that as the most profitable for their companies (since PROFIT is the ONLY think they ever pursue these days! Impressive demos are done to allegedly prove the worth of their (expensive) products, but few such concepts are yet decently proven as effective and efficient in real-life use, and they also tend to need a lot of repairs which generally require incredibly expensive technicians to fix extremely exotic equipment! We tend to see value in the other direction! KISS! (Keep It Simple, Stupid!) The majority of the devices and systems described here are extremely effective but are as LOW-tech as is realistically possible, while still providing the level of results which are expected by modern American and European people. Better than that, many of the devices and systems described and discussed here (and in linked pages) are entirely presented including construction instructions so that you could build your own. And still better, many of them only involve a few hundred dollars of purchases from a local store (and some construction work on your part!)
MOST of the needs of human survival and of some level of happiness can be provided by the following various systems. Given that the economy figures to become even more dreadful than now (early 2009), these systems may turn out to become extremely important in coming years. Beginning about 2004, I have strongly felt that by 2012, the American and most European economies will be in desperate shape, where the Great Depression of the 1930s might be seen as not really having been too bad! (Added note early in 2013: It looks like my 2004 prediction is a little early, but I had not known that the government would be willing to print up unlimited amounts of new money to keep the economy afloat! Some authorities now  are saying that the two 'bubbles' we experienced [tech in 2000 and housing in 2007] will be minor when compared to what they think might or will happen when the 'money bubble' bursts.
Most of these concepts are also applicable to Third World remote locations, so a jungle village in equatorial Africa could use these systems to have reliable food refrigeration and freezing, reliable safe water supplies, comfortable building cooling, heating if necessary (such as for bathing water), and several sources of substantial supplies of electricity for a wide variety of uses, and even medical sterilization regarding health issues. Even aspects of enabling a small greenhouse to produce five times the normal amount of food, at extremely high quality, is in the realm (using the HG 3a).
Additional personal opinions: Whether the news of the day has to do with air or water pollution or global warming or dwindling fossil fuel energy supplies, it seems that every week, some company shows up with some idea where they expect to be given billions of dollars of profits. We had seen solar and wind be heavily promoted in the early 1980s and then quickly fade when they did not perform up to the claims. Electric vehicles did the same in the 1990s. More recently, everyone was agog over Ethanol, where the US gave up 1/3 of its entire cropland to grow corn to be processed into Ethanol. No one seemed to be aware that the MOST that crazy (and VERY expensive to the government) effort accomplished was to replace around 5% of the gasoline we use each year! In other words, a pitiful effort at best which experts should have recommending avoiding from the start. And we hear that Hydrogen is going to be the ultimate solution for energy. But no one seems to recognize that Hydrogen does NOT contain any natural energy on its own - it must be GIVEN that energy from processes such as electrolysis of water, which is a VERY energy intensive process. At best, Hydrogen is actually no better than batteries, which also must be re-charged regularly.
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The biggest aspect of all this is the SCALE of our usage of fossil fuels. An anecdote seems to show this well. Sir Richard Branson made many press conferences where he promised to remove all the carbon dioxide from the atmosphere that we (including his Virgin Airlines) put into the atmosphere. And he and others have shown very small-scale demos of a few of over two hundred different chemical processes we already know about to extract carbon dioxide. And everyone celebrates when an ounce or ten pounds of carbon dioxide gets removed in a demo. Fine. But at some point, the SCALE of the problem must be faced! Say that someone actually sets up such an operation (the Solvay Process appears to be the best chance, and it is well proven over the past 150 years). No one mentions that if you do the math, you quickly find that you would have to chemically process NOT the ten pounds of carbon dioxide in a demo for Reporters, but 200,000,000,000 pounds of carbon dioxide EVERY DAY, and convert it all into either compressed CO2 gas or liquid or some other chemicals. These hundred million tons of materials then would have to be HAULED, each day, to wherever they were going to be dumped, which would require TENS OF MILLIONS OF LOADED SEMI TRUCKS carrying the waste products! Wanna guess at how much extra Diesel fuel would be required, and the cost of those millions of drivers and trucks which would forever be forced to repeat that every day?
The point being, each week's news reports of magical solutions, which usually are HOPED FOR breakthroughs which are not quite ready yet, always leave out massively important facts, generally related to the SCALE of the whole works. A few companies are getting extremely rich because they manufacture wind turbine blades, wind turbines, and wind turbine towers, but amazingly enough, no one seems to have ever done any actual calculations, or confirmed any actual long term performance, to see whether such tower windmills could ever provide significant solutions. The reality turns out to be that around 5,000 giant tower windmills would have to be reliably operating to provide just ONE GigaWatt of electricity. (The United States uses around 500 GigaWatts of electricity nearly constantly!)
So IF it is seriously considered for the US to build around 1,300,000 tower windmills (for at least $15 million each) (think about that for a moment, hundreds of times more tower windmills than there are McDonald's restaurants!), yes, a reasonable attempt at replacing the coal now used in the US to produce HALF of our electricity could be possible. But each of those tower windmills is said to contain around 800 moving parts in them, meaning that more than a billion moving parts would constantly be wearing out and failing and needing to be repaired at the top of 250-foot tall towers! Do you seriously think that is PRACTICAL? Shouldn't the "experts" consider such aspects, rather than just wildly roaring ahead as with the Ethanol adventure? Didn't "Thinking ahead" used to be a central part of all leadership? Where did it go?
It used to be that a technology had to be well proven BEFORE it was ever divulged to the public. Now, products are aggressively marketed and even sold, BEFORE they have even shown themselves to be functional products! The assumption seems to be that once the manufacturer gets all the billions of dollars of sales, they will then be able to finance the R&D that would solve the problems their product has! Isn't that rather backwards? (personal opinion!)
It seems to be common these days to hear terrifying news stories, such as a recent one regarding a VERY highly promoted recent medicine where reports now describe that at least 260 people have DIED from that drug since late 2010 (and it is now still early in 2012!) Pharmaceutical Corporations now seem to be free to immediately start MARJETING their latest drugs to start receiving the billions of dollars of profits they lust for. IF they happen to kill off a few hundred Americans in the process, oh, well! It used to be that even if a SINGLE person died or even got seriously sick or disabled, that Corporation would be forced to stop and their Corporate reputation would be forever gone. Things have really changed, haven't they?
Given the coming economic downturns in the US and in Europe, it may become critical for INDIVIDUALS to explore self-sufficiency regarding survival. It seems likely that tens of millions of people will not have employment or other sources of income, and it may come down to each person and each family having to improvise regarding obtaining basic requirements of life. I truly hope that is not an accurate view of the coming future, but it seems worth at least considering. For now, the majority of people seem oblivious to all of this and only a very small fraction of people are yet exploring alternative energy and related concepts. Most people seem quite comfortable in trusting a few giant Corporations to provide for all of our needs, as they do today.
I have discovered a personal complication in some of these Self Sufficiency systems! In general, I feel the modern social need for having AVAILABLE the conventional electricity and natural gas and water, mostly because I do so many experiments that I sometimes find that some idea did not work as well as I expect, and I then need to rely on conventional utilities. But there is an amusing detail that I had never noticed in my utility bills (which is certainly also in yours!) Some months, I provide NEARLY all the electricity I use, but I wind up buying maybe $3 of conventional electricity in that month. The Utility companies list lots of different things in the utility bills, only one of which is actually the electricity! They charge me $24.28 each month for DELIVERY CHARGES. Then, based on the total of product and delivery charges, the government adds in $4.85 in taxes. So even in a month where I only actually BUY $3 of electricity, I have to pay about TEN TIMES THAT MUCH or around $32! The same situation is true for natural gas supply, where I actually USE a tiny amount but every month I get billed for about $30 minimum. The darkly amusing fact is that, in YEARS that I have been really serious about self-sufficiency, and I have actually USED maybe $30 of Natural Gas in a year, I have had to PAY around $400 DURING THAT YEAR (nearly entirely for the AVAILABILITY of conventional utility supply). And about another $400 minimum per year to have conventional electricity supply available!
A darkly amusing result of these things is that even for a man who is so motivated about self-sufficiency as I am, some of the motivation is faded! Even when I now get 'lazy' in not wanting to always carry bags of cut lawn grass for my HG 3a on really cold days, the net annual cost of such 'partial reliance on conventional utilities' is barely noticeable regarding the bills! Having become elderly and having some physical maladies is my usual excuse now, but I think it really is an element of laziness!
Around 1970, the US was known to have more Uranium than any other country. The USA had mined and used up all the Uranium it had during the Cold War, and by around 1992, all the 39 operating Uranium mines in the US had closed due to lack of available Uranium! Ever since then, we have had to IMPORT virtually all the Uranium we use in our electric powerplants! Have you noticed that NO ONE has ever told you about that? Fortunately, Australia and Canada have been selling us Uranium, but even those supplies are getting used up. And the old reliable hydroelectric dams are getting near the ends of their useful lives. The 700-foot tall Glen Canyon Dam (in Arizona) already has frightening amounts of water leaking AROUND IT through the sandstones of the region. This is weakening the attachment of the dam to the bedrock, and when that dam comes loose from the rock and falls over, a true catastrophe seems certain to occur, AND SOON. In addition, the enormous reservoirs of those dams have been filling with sediment for decades, so they have less water in them now and at less depth, so they have far less capacity to make electricity than they used to have. Nearly all hydroelectric powerplants now have to release water FASTER than ever before, just to supply previous (Government contracted) amounts of electricity, and yet the demand keeps increasing! (It may actually be fortunate for that dam's future that the level of the water in Lake Powell has been more than 100 feet lower than it should be, regarding that water leaking around that dam.)
I have studied these matters for more than 20 years and I see NONE of them as being realistic supplies of energy beyond maybe the year 2020. That AIN'T VERY LONG from now! And so I have attempted to consider other energy related ideas.
However, there was a difficulty! It turns out that the US Army Corps of Engineers has absolute jurisdiction and authority over ALL navigable waterways in the US. So I learned that I had to call them to make sure I had their permission. (This was BEFORE they showed themselves to be totally incompetent regarding the miles of dikes they had built around New Orleans, which failed miserably a year later!) The man I talked to on the phone certainly believed himself to be higher than God! He told me that they did NOT want any suggestions from any amateurs. He then explained to me that IF there was any such good idea, that THEIR people would have thought of it, as they had the smartest people on Earth! He then insulted me, finding anyone who claims to be a Physicist to be stupid (and more, including some swear words), and he even felt the need to directly threaten me regarding even thinking about touching any of THEIR dams, before he slammed the phone down on me. The US Army Corps of Engineers has the ONLY game in town, and I will NOT play by such abusive rules! I will NEVER release that (wonderful) system!
OK. That is NOT on the scale of National energy consumption, but maybe much larger ponds could use this Tidal Energy for greater performance.
The friction in the culverts should be minimal as the water flow would be very slow, just 10 miles over a six hour period, less than half of walking speed. Energy conversion methods are not particularly efficient, but even if only 50% could be captured, that would still be around 22 kWh of electric energy captured and converted to electricity, in that six-hour or three-hour period. It would occur again around 13 hours later, so around 40 kWh of electric energy might be available from such a system.
There ARE two serious disadvantages to this idea! One is that salt corrodes concrete and salt deposits might also accumulate inside the culverts. The other is that this method would be intermittent, only providing maximum electricity for about 3 hours out of each 13 hours. STILL, it would be rather cheap to install, and where extremely few moving parts could ever fail!
I only include this idea in the spirit of trying to be comprehensive in considering all available possibilities, and I personally do not see broad application for it regarding our energy needs.
Photovoltaic Cells, PV, Electricity from Sunlight (Jan 2002)
Practical Wind-Generated Electricity (Residential, some Watts) (1975 and April 1998)
Practical Large-Scale Wind-Generated Electricity (Community, 1.2 MegaWatts, a thousand homes) (June 2007) (a million construction jobs and 12,000 MegaWatts of electricity Nationally)
Hydrogen as a Fuel for Automobiles and Other Vehicles (August 2003)
Battery-Powered or Hybrid Cars and Hydrogen-Powered Vehicles (April 2006)
Methods of Storing Energy
Published Actual Energy Supplies, Coal, Oil, Natural Gas, Uranium (May 2010 Report)
How the Sun Works in Making Light and Heat
It would be wonderful if the products were actually likely to be able to do that! But it RARELY actually occurs! It seems likely that SOME DAY those claims may be credible, like twenty or fifty years from now. But for now, there is IMMENSE "optimism" involved! The companies that manufacture such things always do their "official tests" under absolutely perfect conditions. If it is solar, that means perfectly clear weather, exactly at noon, pretty near June 21 when the Sun is highest, wind blocked, and with all other conditions carefully controlled. So, when they advertise "can produce 7 watts per square foot", that is technically and legally true. However, when actual weather is added into the equation, and the fact that the Sun is NOT at that maximum height except for a few minutes on one day each year, and there are many other losses, the REAL yearly performance that people experience is often 1/10 of what salespeople generally try to promote. As far as I am concerned, that is outright deception, as it is the basis on which rather expensive products and systems are being sold. Yes, they are VERY careful to have done those very specific tests so they can minimize losing lawsuits, but beyond that, they generally seem to have just discovered some types of products where customers seem willing to pay out enormous amounts of money based solely on what a salesperson says! They see it as a gold mine! Didn't a lot of people travel around a hundred years ago selling Snake Oil as the answer to absolutely every malady? Isn't there sort of a similarity? That Manufacturers and Salespeople should at least TRY to be honest with customers? Where is THAT today?
There are separate web-pages on photovoltaic cells and on wind power in this Domain, linked at the end of this presentation, if you should want to better understand the actual Physics behind what ACTUALLY occurs. Since I am a research scientist, and not trying to sell you anything, I have no reason to either puff up or denigrate any technologies. Yes, the text below mentions the JUCA woodstoves which I invented in 1973 and which even now keep around 100,000 Americans warm every winter. But I really do not care if you or anyone else BUYS those products (and actually never really did care, except to HELP people!). They just happen to operate far better than any other things that have been sold. I suppose that is a bias of sorts, so DON'T BUY ONE. THERE! My interest in ALL these pages is simply to try to provide you with sufficient information where you might spend your money wisely, whatever you choose to buy!
AND, if you are patient enough to be prepared to wait twenty to fifty years, I suspect you might then be really pleased with a wide range of solar and wind products then manufactured and sold, except maybe with the costs involved!
In my opinion, most major purchases need to meet certain requirements regarding AMORTIZING their own cost. That is, they need to show me that they have a realistic chance of actually saving enough eventually so that they will likely eventually pay off their own (installed) cost. Only then could any of them be considered as ways to actually SAVE people money, where they could ever be seen as a way of actually saving any money on energy needs! When someone spends $12,000 for a wind-turbine, and another $3,000 for a tower for it, my first thought has to do with how long it is likely to last and how much maintenance it will require. For discussion sake, say that it was likely to last about 20 years (relatively unlikely, as very few of the wind-turbines sold in the 1980s are still working), and that it was designed and built so well that ZERO maintenance was needed in those 20 years.
Thought: You could place that $15,000 in a Savings Account and earn maybe 5% interest over those 20 years, which would result in your then having $39,800 in the bank.
If you are an average family, you have monthly electric bills of between $50 and $100 per month, or $600 to $1200 per year. In 20 years, you would spend between $12,000 and $24,000 for electricity. Yes, the cost of electricity WILL go up, but unless the wind-turbine will supply you at least $39,800 of electricity (and it clearly would not, since you will not even USE that much in those 20 years, even with no maintenance and perfect operation for 20 years), it will never even pay for ITSELF, much less actually save you any money! IF you are willing to amortize over 40 years instead, yes, it has a shot of eventually paying for its original cost. I am a patient person, but not THAT patient!
See the general approach to trying to figure out whether such things are worth buying?
This applies to Electric Cars or Hybrids or Wind-Turbines or Solar Concentrating Collectors or Solar Flat Panels and any future devices that will claim to use Hydrogen. Even woodstoves!
How about the guy in Maine that constantly gets massive media attention regarding his "all solar" house? He freely admits that he paid over $50,000 for the equipment on his roof. He even says that he got special deals on that equipment and that it normally would have cost twice that, or $100,000! Reporters always visit DURING THE DAYTIME, AROUND NOON, IN THE SUMMER, and WHEN IT IS SUNNY, so they see the system providing all the electricity his house needs (at that moment), and even a little extra which he can sell to the electric company. However, even on such a sunny day, around 3/4 of the hours of the day are when the Sun is down or too low in the sky, or in the wrong part of the sky, to be of much benefit. And, unfortunately, we only NEED to have lots of lights on AT NIGHT, when no Solar is being collected. So, all night, even his famous house needs to buy electricity from the power company. Since he is a very environment-aware person, clearly he does not leave lots of lights on in rooms that are unoccupied! And the net result, FOR HIM, is that over a summer month, he generally does not pay for electricity he uses.
Again, superficially, that seems incredibly impressive. However, his situation is much like the one discussed above, where during the expected lifetime of the solar panels, there is NO chance that his initial costs will ever amortize themselves. He even admits that, in telling reporters that his system will never actually pay for itself. But I wonder if his aggressive promoting of that approach doesn't mislead others into buying many thousands of dollars of solar equipment, under the impression that they are going to "save lots of money!"
I have not seen any reference to the actual total area of solar PV panels he has on his roof, but it may be around 2,000 square feet. That would mean that the PV panels could realistically produce around 14,000 watts in the hour around noon on a very sunny day. The weather is never that perfect, except possibly in the desert, so the Maine cloudiness factor must be included, and we are down to around an AVERAGE 5,000 watts in that hour, or around 12 to 15 kWh of electricity in that entire sunny day (after geometrical and other losses). Converting this to AC electricity which is acceptable to the local power company is not easy, and involves some very expensive equipment. But say that NO electricity is used at all in the house in a 24-hour period, and all the electricity created would be sold to the Electric Company. Yes, you BUY electricity for around 15 cents per kWh, but for starters, a good portion of that is for Delivery costs and an assortment of taxes. The actual cost of the electricity is probably closer to 10 cents per kWh, but the Electric Company charges you several new expenses, specifically for them to constantly confirm that any electricity you supply is at EXACTLY the correct frequency and EXACTLY the correct phase-angle to be compatible for their equipment. They commonly charge some extra fees simply for having to waste their time to pay attention to you! The result of all this is that you are not likely to even receive 5 cents per kWh for each of those 12 kWh that you could sell them. That's sixty cents you might be able to make on that sunny day. You installed a hundred thousand dollars worth of solar panels FOR THAT? Would that really merit the giant smug smile of "independence"?
You might note that at a MAXIMUM of producing $0.60 of electricity on really sunny days, you might realistically be able to sell a MAXIMUM of around $100 of electricity in a year, even in such an amazing house. So then how many years will it take before that guy in Maine amortizes $100,000 worth of solar panels on his roof? Answer: Around 1,000 years, if everything worked really well and nothing ever broke down! Duhhh???
I actually FULLY support such houses, as EXPERIMENTS! And I think it is wonderful that he is NOT causing massive global warming caused at the electric powerplant. Those things are fine! It is only the "misleading others into being receptive to things that salespeople are ready to tell them to sell expensive equipment," which bothers me!
In the 35 years that solar energy and wind power have been aggressively promoted as sources of electricity, there have ALWAYS been endless numbers of people who CLAIM that they sell electricity back to the power company, always with a giant smile. This statement is nearly always made BEFORE they actually have any real experience! During those 35 years, I have regularly tried to get ANY such homeowner to make photocopies of a year's worth of electric bills, so I could see actual documented evidence of just how much they were paid back by the electric company! NO ONE has yet provided those photocopies! I am certain it is because the most impressive performance they have ever seen would be laughably small! Did their electric bills drop from $150/month to zero? Not even close! Did their electric bill OCCASIONALLY drop from $150/month down to $149.50/month? I could believe that. Actually, their bill reductions might be much greater due to an AWARENESS of conservation. It is all actually a GOOD thing, but I think those owners are ashamed for having spent so many thousands of dollars and done so much bragging, to only have something like that to show to any Reporter! Personally, if I had invested massively to get a full-blown solar installation or a Windcharger system, I actually WOULD have done what is called a Statistical Analysis on the previous year's electric bills and also on the bills of this year, and even if it only resulted in me saving enough money for a cup of coffee, I would certainly have showed the ACTUAL info to Reporters! Please realize that Reporters NEVER see any ACTUAL data regarding these sorts of products, so their news reports are essentially what the person being interviewed wanted to say! And THAT essentially came second-hand from salespeople FROM THE MANUFACTURER! The simple fact that Reporters only visit such houses on bright sunny days (for solar) or windy days (for tower windmills, pretty much stacks the deck regarding what viewers are going to see!
This is IMMENSELY FRUSTRATING for me! Even with my advanced education at the University of Chicago in Physics and Engineering, it took me several months to Engineer and Design the free Air-Conditioning system. To then see thousands of people blow that off, and only read enough to get the basic idea, and then slap something together, simply tells me that they will get INFERIOR PERFORMANCE from what I had tried to provide for them!
Now, there ARE Mechanical Engineers who are capable of doing the math to improve my designs. I have no problem when such people decide to alter what they will build. But that seems to be a tiny fraction of the people who actually build them!
My attitude is meant to be HELPFUL, in nearly every sense of the word. But I DON'T want to feel a responsibility when someone makes bone-head alterations to any of my systems and then winds up having something that barely works at all!
My attitude might be expressed clearly regarding the "self-ice-and-snow-melter" system described below. IF someone can show me that he/she can determine the Reynold's Number which applies inside that device, and then explain to me why that number is desirable, I would welcome and encourage that person to make as many changes as they wish to that device! For anyone else, who could not do that Engineering, I feel that they really need to build something very close to what I have described! Comprende?
This seems to suggest a REALLY simple idea! Consider getting TEN standard car batteries (for around $500 total cost, and maybe less if they give you a quantity discount, or far less if you get used ones.) and connecting them IN SERIES. You would then have a supply of 120-volt DC electricity. Better, a HUGE supply of it! Most car batteries are rated at being able to provide 500 amperes for a short time (to start a car) and around 90 ampere-hours total actual energy capacity. This means that each could supply a continuous 30 amperes for 3 hours before the batteries were drained! Being wired in series like that we would have a supply of around 90 ampere-hours times ten batteries total of 120 volts, or in other words 11,000 watt-hours (or 11 kWh) of available electricity.
That is an impressive amount of available electricity!
Given that our normal family modern-lifestyle use averages only between 1,000 watts and 2,000 watts in the evening hours and far less during other hours, we are talking about having LOADS of electricity with this battery approach! I am talking about a MODERN life style, where kids forget and leave lights on in rooms and all the rest. So you are looking at an electric supply system that can provide ALL the electricity your (NORMAL) life requires for something like 24 straight hours before being drained! And you CAN use things like the kitchen toaster (which operates for such a short time that it uses so little electricity from those batteries as to have virtually no effect whatever!)
A SINGLE car battery contains a LOT of energy in it, enough to start your car engine! Ten batteries contain ten times that amount of energy. Basically, a family could have massive Christmas decorations or operate a buzz-box welder, in other words, have no realistic limitations regarding using electricity!
By the way, the US government makes it relatively difficult to obtain ten USED batteries! Companies that sell new batteries wind up having lots of used-but-fine-for-our-purposes batteries which they then have to dispose of. They are not ALLOWED to sell you or give you any of those batteries! Politicians feel that used batteries are too dangerous to have around and so strict laws were passed to make sure that they are all given to companies that make a fortune in recycling the lead in them! I have discovered that obtaining used batteries is not easy because of this, although I do not see the logic in having to buy 10 brand new batteries when their capability is not necessary. It has been suggested that junkyards wind up having a lot of batteries that they hate to have to pay to dispose of! Hard to say the quality of the batteries from a junkyard, but they should be very cheap!
You can estimate your current usage in other ways. Say your monthly bill is around $60, which means that your daily bill would be around $2. Part of the bill is for other things, so if your electricity rate is 15 cents per kilowatt-hour, this suggests that your (wasteful) daily usage might be around 10 kWh. This is comparable to the 12 kWh that we indicated available from the ten batteries, which confirms that we really DO have an electricity source that can realistically support a modern lifestyle for a family, without having to do Abraham Lincoln type reading by a candle! And even THAT level of usage is assuming that no re-charging was going on at all during the entire day!
(For all the devices that require AC current, you could buy an INVERTER, a device that takes DC current and converts it into AC current. The important point here is that you would have LOADS of available electricity to drive all your TVs and computers and refrigerator and hair-dryers and microwaves and all the rest!)
People who attempt to go off-grid tend to worry about using even 20 watts for a few minutes, and they rarely have more than one or two small lights on at any time. I am talking about being able to have a HUGE Christmas light display, for the hours from dusk to bedtime, every day!
Of course, you would have to be able to CHARGE those ten batteries! This is a bigger issue than it might first seem!
Since one horsepower is equal to about 746 watts, our daily use of 10 kWh to 15 kWh of electricity means that we used up about 13 to 20 horsepower-hours of electrical energy. This is a LOT, and it takes a SERIOUS effort to try to recharge that much electricity!
You COULD try to use photovoltaics to do that, although in my opinion, they provide a pitiful amount of electricity. IF you are going to seriously consider buying many thousands of dollars of them, find someone NOT working for that company who has used them for at least a year, to find out how much electricity they REALISTICALLY are able to use from the solar cells. You may be surprised. IF you had a waterfall or river nearby, you COULD build something to get electricity from a crude hydroelectric setup. But my favorite approach is to simply get a bunch (10) of discarded 55-gallon drums and an equal number of old car alternators (I prefer GM). You probably need to buy a single sheet of top quality exterior or marine grade 3/4" plywood (to make very large wooden pulleys!). Each setup will charge just one of the batteries.
So you cut ten of the drums in half, and make ten simple Savonius rotor wind turbines. In a 10.7 mph wind (the average here in the Chicago area) (that is around 16 feet per second), that Savonius rotates at around 3 times each second (with no load) and around 2 rps with a decent load. That is 120 rpm. The car alternator has a pulley on it that is about 2" to 3" in diameter. SO, if you cut a circle out of that plywood which is maybe 20" in diameter, and make the appropriate groove in the outer edge for a standard car fan belt to fit, you have essentially made a large wooden pulley to drive a fan belt, and you can then simply and easily cause the alternator to spin at 7 to 10 times as fast, that is 840 rpm or 1200 rpm. Most alternators can produce most of their power at those speeds.
Long ago, Rankine found that undisturbed wind contains power from kinetic energy (energy flux) equal to:
E = 0.5 * ρ * V3 * (area exposed to the wind).
Note that this is a simple application of the kinetic energy definition. ρ is the air density or 0.00237 lbf * sec2/ft3.
For the 16 fps average wind discussed above, and for a standard 55-gallon drum Savonius, we have 0.5 * .00237 * 163 * 10 square feet or about 50 ft-lb/sec. Since one horsepower is 550 ft-lb/second, this is therefore about 1/11 horsepower, as shown in the wind page analysis. We also learned there that the Savonius only has an efficiency of around 14%, so we really are only getting around 7 ft-lb/sec available to the alternator. That turns out to then be about 1/80 horsepower, or roughly 10 watts. So with a single simple Savonius made from an old 55-gallon drum, in an average wind, we can expect under one ampere of power (at 12 volts) to try to charge each of the batteries.
(A momentary aside here! You have heard friends brag about they're "about to go off-the-grid and about to be making 2,000 Watts continuously or 5,000 Watts continuously from some sort of wind turbine or PV that a salesperson has told them about! In our wind-energy page, we did the calculations that show that a LARGE farm windmill, 10 feet in diameter, at its higher efficiency of around 30%, can only create about 120 watts of mechanical rotational power! When people repeat what salespeople tell them about 2,000 watts or 5,000 watts, they have no idea how unrealistic that is! Except that in a hurricane, yes, that would probably be true!)
Our 7 ft-lb/second from our little (and cheap) Savonius is around 1/80 horsepower, or around 9 watts of power. The belt and the alternator have mechanical losses, so 6 watts of actual electricity is pretty realistic for our 10.7 mph average windspeed. SO, we set up TEN of these Savonius/alternator setups spread out in a yard or field, each connected so that it charges ONE of the ten batteries. This is rather slow charging, granted, about the equivalent to a trickle charger, around half an ampere of charging current. (Sadly, that total charging rate, of half an ampere at 120 volts or 60 watts, which is 24 hours a day when the wind is blowing, is actually comparable to the DAILY AVERAGE charging of even fairly expensive solar PV roof panel charging systems.) Because the GM alternators have voltage regulators built into them, they can merrily spin or not spin and always gradually be trickle-charging each of the ten batteries.
(Some of this was invented and built around 1974 and improved around 1998. Other approaches have been more recent.)
IF you insist on seeing impressive claims, we could have given performance for when there happens to be a 40-mph wind blowing near you. Yes, that happens, and salespeople seem ready to use things like that as an example. Because wind carries power at the third-power of the speed, when we nearly quadruple the windspeed, we then are working with wind that has more than 50 times as much power (43 is 64) in it. So we could have been discussing here charging currents of 25 amperes for each battery rather than just a half an ampere. And then we could be saying 25 amperes times 12 or 14 volts times ten alternators and we could be puffing about producing 3,500 watts of power being produced continuously. Sure, as long as the wind keeps going at 40 mph!
Now, getting back to reality!
Keeping in mind the massive electrical storage those ten batteries can have, you can merrily use up electricity as we are now all used to doing! You could certainly use a standard kitchen bread toaster! I suppose you could even use an electric heater (1500 watts, around 5,000 Btus of heating) if you wished! But the chargers have to eventually give the batteries back the same amount of electricity. At 0.5 ampere charging current, it could take quite a while if you seriously deplete the batteries by very heavy use!
If you have a lot of space available, and a lot of scrap drums, you could make more Savonius rotor assemblies! If you made FOUR for each battery, then everything would charge at 2 amps, about 250 watts nearly continuously. In one average day, you could then charge the batteries with 24 * 250 or 6,000 watt-hours or 6 kWh. Our modern life, with all of our appliances, generally uses up around double that. SO, if you would want an ABSOLUTE NORMAL usage / wastage of electricity as we now do, where we use up around 12 kWh per day, all you need to do is make EIGHT Savonius rotors for each of the ten batteries! You probably would even have EXTRA electricity that you could share with neighbors! (In general, you have to figure that neighbors would NOT be pleased with your yard! When they would see 80 ugly spinning old drums in your yard, it will be difficult for you to convince them that it is really just modern art!
People who try to be "off the grid" tend to only have one or two small lights on at any time. What we are talking about here is having the house blazing bright, and probably even covered by a gaudy Christmas display in that season!
Note that all this is FAR less expensive than the $10,000 or more that you probably would need to spend for a pitifully inadequate bought photovoltaic or wind-charger system, and it performs easily ten times better! However, if you have close neighbors, they probably would not appreciate looking out and seeing 80 Savonius rotors always spinning! Worse, if you economize by not actually using any bearings, they sometimes squeak when they rotate (like some rooftop ventilating fans do).
If you use GM car alternators, they each already have built in a voltage regulator, which keeps it from over-charging the battery, so the alternator can simply be directly connected to the battery. As to finding enough scrap drums and alternators, that would be up to you!
Obviously, it would be possible to BUILD Savonius Rotors that were larger, say 3 times taller and 3 times wider, so that a single rotor could provide all the electricity for one battery. THEN you would only have ten of these buggers in your yard! Notice that the single car alternator still has massive extra capacity. We would still be only charging at around 4 amperes (the equivalent of eight of the 0.5 amp drum-versions), and car alternators are generally rated at around 60 amperes. Yes, when you have a storm and 30 mph winds, where (27 * 4) 108 amperes of charging could be available, you would be limited to the 60 amperes that the alternator would allow, but that really only means that you could turn on even MORE lights when it is stormy!
There is one further issue to consider. Say that one of the Savonius rotors seizes up or falls over, or a belt breaks or falls off, or an alternator fails. It would be good if you could know that! Otherwise, ONE of your batteries might no longer be charged and might completely get drained. However, there are really simple solutions to this! One of the very simplest is to get 10 electronic resistors of 100K value. Wire them in series, and across the entire 120 volt DC output of your system. Connect a wire from each wire between batteries to the same wire between resistors. Add sensors, voltmeters, or assorted other things to monitor the voltages between each pair of resistors. As long as everything was working right, the voltages should always stay very close to 0, 12, 24, 36, 48, 60, etc. IF any of the voltages got more than a volt away from those known values, you would know that something was wrong in a battery, alternator or rotor. Simple, cheap and easy.
These comments have been focused on Savonius rotors made of old 55-gallon drums, because they are so dirt cheap and quick and easy to make. (See the WIND presentation in this Domain for detailed information.) But solar IS possible, especially if and when solar PV panels get a lot cheaper and a lot more efficient. Also, if you have either a waterfall or a consistently flowing creek or river accessible, that energy could also provide the power to drive the alternators. If you have an outdoor wood-fired boiler, it could produce steam to drive small turbines to drive the alternators. If you approach this all creatively, you can find good solutions to nearly anything!
Personally, I like the idea of making an INDEPENDENT set of wiring inside the house for 120 volt DC. The same SIZE of wire, 14 gauge or 12 gauge, is fine, but I recommend getting some different color wire, such as pink or blue so no one would ever confuse it with the house's 110 AC wiring! Each room could have two separate ceiling lights, possibly in a single device, one being a bulb that was supplied by 110 AC and the other bulb that was supplied by the 120 DC. Wiring the light switches might be an adventure, but certainly easily solved.
In any case, during 2010, I have discovered a variant of that earlier device, one that has the performance of my 2003 system but which is remarkably cheap and simple to build in around two hours! I may soon be living in a tent on vacant property, if that strange man Nolan has his way in Demolishing my house to punish me for challenging his infinite authority, but I am currently providing the necessary instructions for that new device, like I have done for several other useful systems. It is at mb-soft.com/public3/electzzz.html My demos of this are constantly impressing even me, and THAT is not very easy to do!
The second concept was briefly mentioned above. It seems certain to be something that will require years of research and refinement before it could ever be used on a practical basis. As a young man, I chased at least half a dozen tornadoes, as I was impressed with the power they contained. Above and in a linked web-page, my fascination has persisted and between 2000 and 2009, I learned how the physics of tornadoes operates, and even got up enough nerve to create a few dozen of them (REALLY little, very CONTROLLED ones!) I proved to myself that there seems some potential there when I kept a tiny tornado spinning for around two continuous hours (in my basement!). Being practical, I do not see that the tornado concept has any realistic chance of providing significant electricity before the year 2020 or so, or maybe even later yet. But it is the sort of thing that intrigues me!
It is a variation of the residential-scale Savonius Rotor approach, but with several sophistications added in for greater performance. And also built on a far larger scale!
It turns out that the NORMAL wind (at around 10-mph speed) that passes through one square foot of area contains about 5.0 Watts of mechanical (kinetic) power in it. If through an area 100 feet tall and 2,000 feet wide, and including the effect that windspeeds are higher at higher altitude and that the power in wind is proportional to the CUBE of the windspeed, that area of wind contains around 4.4 megaWatts of wind power. It turns out that by building some large concrete walls, and a few other simple devices, a reliable 1.2 megaWatts of electricity (and usually much more) can be captured from this area of wind. THAT is about the amount of electricity that roughly one thousand modern homes USE NOW!
A local business or bank would need to agree to put up around $1.8 million dollars for construction. Nearly half of that will be paid to about 100 LOCAL construction workers in building the concrete walls! About one-third of the total cost will be spent on buying and trucking in a lot of sand and gravel and Portland Cement with which to mix the concrete (on-site).
At a common cost of electricity today, 15 cents per kiloWatt-hour (nearly half of which is often Delivery fees and taxes), with really constant wind, that amount of electricity might be sold for around $1.7 million EACH YEAR! In a year, or certainly before two full years, the ENTIRE FACILITY would have paid for itself in profits from the electricity produced! (NONE of the giant wind-farms can even say if or when they will ever be able to be a profitable business! And they concede that dependence on many tower windmills will RAISE the cost of electricity a LOT!)
In addition, it turns out that in 1992, the US Government initiated a Program called the Production Tax Credit (PTC) which is now 2.0 cents credit for every kiloWatt-hour produced for the first ten years of operation. Even if all the electricity produced was given away for free, this credit can be about $210,000 for each of the ten years, in other words ENTIRELY paying for the entire $1.8 million construction cost of the whole facility!
In addition, such LOCAL projects in each small town could encourage and inspire local businesses and local banks to again get back into their normal operations! If only 10,000 towns decided to each do this, each hiring 100 construction workers in the process, you might notice that is a MILLION NEW JOBS, all of which are good-paying and full-time! Not bad, eh?
(This was first fully Engineered in 2008)
This system is presented at: Practical Large-Scale Wind-Generated Electricity (Community, a thousand homes) (June 2007)
There are many brands of woodstoves which now have decent efficiencies. The older Potbelly and Ben Franklin stoves only had around 25% efficiency, but modern airtight woodstoves are often above 60% efficiency (although they brag about even higher numbers in carefully controlled tests). Unfortunately, the airtight woodstoves have two enormous problems. The first is that by forcing a fire to try to burn without sufficient oxygen, it cannot burn very well and that both tends to create pollution and creosote and also has lower efficiency as a result. The second is that the price of nearly any of the quality airtights is over $3,000, and they are all really tiny products (which was necessary for their air-tight products to pass government pollution testing), making it difficult for an owner to ever haul and burn enough wood to even pay for the woodstove! (That amortization thing again raises its head! Partly due to the tiny firebox not being able to burn enough wood to make using it very worthwhile, and partly because many owners tend to stop using it after one winter of enthusiastic use!) Again, the only exception to this that we are aware of was the (NON-airtight) JUCA B-3B/B-3A woodstove, which, since 1973 had an overall seasonal efficiency of around 81%, and which was actually a central furnace which happens to burn wood. However, the JUCA units had a disadvantage in that they all use rather large and powerful blowers to spread the heat throughout a house. That is normally not a disadvantage, except when the electricity for the blower must be generated on-site! The JUCA woodstoves were invented in 1973. (A link to the JUCA web-site is in the links at the end of this presentation.)
Therefore, far better than any of the above is the HeatGreen 3a unit which YOU can build with around $200 of common local materials! (Some day there will be an HG 4a unit!) This system is unique in NOT having any flame or fire! It allows waste organic materials (cut grass, leaves, weeds, crop residues, etc) to NATURALLY decompose, which happens to release amazing amounts of energy, which this technology then efficiently captures. It still boggles my mind that the cut lawn grass and leaves and other organic residue from a single acre of land ABSORBS around 170,000,000 Btus of sunlight in the process of photosynthesis in making those materials, which then all must be RELEASED because of the Conservation of Energy! So that single acre calmly and quietly releases around 170,000,000 Btus of heat energy during the year, while your house likely only needs a supply of maybe 50,000,000 Btus for the entire winter! Duh? Entirely GREEN, too! The operation of an HG 3a seems to be an acquired skill, but once it is mastered, the operation commonly releases more than 95% of the chemical energy in the organic materials that are put into it to decompose. That is tremendously better than any woodstove or fireplace! (This was invented in 2007) (This system was offered to Europe, the European Union, and the government of the Ukraine in 2007, and then to dozens of leaders in the Ukraine in 2008, although no one then seemed interested in enabling homeowners to keep their houses warm, when the Russian supplies of natural gas were shut off those two times.) Two web-pages are important regarding that device, the first of which explains what it is and why it works, at:
HeatGreen - A Non-Fossil-Fueled Home Heating Furnace System (March 2007) (biodecomposition)
The second contains all the instructions to build one!:
High-Performance HeatGreen Home Heating System Version 3a (Construction) (March 2007) (biodecomposition)
We have yet other non-fossil-fuel approaches to heating a house and its hot water. One is low-tech and the other is higher-tech!
Low-Tech Active Solar Heating for Buildings and Water (April 2007)
Heat and Cool a House without a Furnace or Air Conditioner (hidden) (1977, Nov. 2000)
Finally, in a more sophisticated way, and higher-tech, if you do not want to have to carry grass and leaves to put into a HG 3a for heating, there is an alternative, but it is somewhat more expensive to have. It is the NorthWarm whole-house 100% solar heating system. It was invented and fully Engineered in 1978 and 1979. There are two Versions. The first is most efficient, where the house is NEWLY built with the Version 1 system intimately being part of its structure: (We are confident that a Version 1 would be able to ENTIRELY solar heat a home for the entire winter in most locations in the southern half of Alaska, and certainly nearly anywhere else.)
NorthWarm Totally Solar Heated House - Version 1 (1979)
The Version 2 is a more limited variation of Version 1, for EXISTING houses, where a separate two-car-garage-sized out-building must be built and with underground heat tunnels between that structure and the existing house.
NorthWarm Solar-Heated House - Version 2 (1979)
The Version 1 of the NorthWarm system is so efficient and so effective that it INCLUDES an air conditioning system as part of Version 1! That air conditioning system has been made available to the public (for free) beginning late in 2000, and it is the Free A/C system discussed below.
Alternatively, if some spectacularly strong water pump could be obtained, two much smaller pipes might be sent down a single borehole. The premise would be to pull water up that 3500-foot deep well, and since that water was always at around 120°F, just send the water through standard hydronic room radiators, to heat each room of a house, forever. The problems here, in addition to the cost of the 3500-foot borehole, are that the pump (at the bottom) would have to pump water at around 1700 PSI, and that all the pipes would have to be extra-heavy to withstand that pressure.
Say that you have a bedroom which is ten feet square and eight feet tall, a little smaller than average, maybe, but it will be used here for this example. That bedroom therefore has a TOTAL SURFACE AREA of 520 square feet (easily calculated). Now say that you insulated the heck out of the walls, ceiling and floor of that bedroom, to somehow get everything up to R-100 insulation. (Most bedroom walls are not insulated at all, except for the walls that are exterior walls.) (You should note that R-100 takes a LOT of insulation! It is 20" thick of foam insulation, and even thicker fiberglass!) Now say that the average temperature of adjacent rooms is left to cool during the night (unheated, to save money on heating bills) and they drop to around 45°F during the night. And you like to have your bedroom at a cozy 70°F, even warmer than most people do. We can calculate the total heat loss of that bedroom from these figures! It is the total surface area times the temperature differential divided by the R-factor of the insulation. In our case, this is 520 * (70 - 45) / 100, which is about 130 Btu/hour.
It turns out that the human body, when asleep, commonly burns up around 80 Calories per hour, which converts to about 320 Btu/hour.
If that bedroom had been absolutely sealed tight, the (one) human body inside it during the night would be GIVING OFF around 320 Btu/hr, while the room was only LOSING around 130 Btu/hr! (due to the incredible levels of insulation installed surrounding it). This is actually the EXACT same reason that a sleeping bag works to keep you warm in any climate!
You can also see that these calculations show that even if the adjacent rooms were at below zero temperatures, that one human body would STILL be able to keep the room as cozy as desired!
There IS a disadvantage in this system! The heating source (the one body) has such low heat output that at the START of a night, the room could take some time to warm up, because the air in the room and all the objects within it must all be warmed up as well. Again, when you FIRST get into a sleeping bag, you can be cold for a minute or two, but then become toasty warm fairly soon. In this case, we need to heat up a LOT more mass of materials to get the whole room warmed! And also, IF a door is opened where really cold air was able to fill the room, it would again require some time before all that air was again heated to the desired temperature.
I have tried this and it works! Amazingly well! But I actually then modified my experiments to involve the equivalent of a canopy bed, where the delay of warmth was then rather minimal in getting the air inside the canopy chamber and the bed warmed, just a few minutes, where then I would loosen the canopy walls once I became toasty in bed, where the room then gradually warmed during the night.
One WONDERFUL aspect of this is that IN THE MORNING, I always woke up to a wonderfully warm bedroom, even though it was technically unheated and even when the outdoor temperature was below zero! LEAVING the cozy bedroom to go to a rather cold kitchen, was a different matter!
Note: It is NOT a good idea to SEAL such a bedroom, because during the night you consume oxygen from the air, and you don't want to cause any situation where you might not have sufficient oxygen in the air you were breathing. In fact, THAT is why we used the parameters we did, where the heat being released by the body is nearly three times what is actually necessary to heat the room, such that a MODERATE amount of air circulation can be allowed through the room. Again, it is NOT a good idea to get ENTIRELY inside a sleeping bag, but to arrange it so that your nose is able to use air which is outside the sleeping bag! Otherwise, you could easily use up too much of the oxygen inside the sleeping bag and possibly have a health emergency result.
So a variant of the HG 3a device is designed to only have enough capability to heat the domestic hot water and not also heat the whole house. The standard HG 3a also has the capability of having a long coil of large diameter water pipe inside it to be able to do both jobs at once.
However, there are MANY ways to try to heat domestic hot water! There are many products sold which try to use solar energy to heat the tank, but they tend to have very minimal effectiveness. They are sort of variants of the black plastic bag you can buy for camping where you hang it to get heated in sunlight so one person can later take a shower. They WORK, but with very limited capability. There are products sold as swimming pool heaters which are similar, and which can have some value, but it is limited.
There are a LOT of ways to heat a MODERATE amount of domestic hot water! Some small tanks have been manufactured and sold to go inside a woodstove or fireplace, which work, but many were poorly designed and they have the capability of bursting due to extreme high steam pressures which can develop in such environments. Such devices must have several safety valves on them to release excessive pressure.
Here is another approach. I have never heard of anyone trying to do this, but it certainly has plenty of capability of heating domestic hot water for a family. It is actually based on an OPPOSITE application of a characteristic of Ideal Gases of what is described below for providing food refrigeration, food freezing, and the earliest (1846) form of building air conditioning. In this case, the SAME device is used, but the underground cooling is not used, only the heating effects of compressing air. See the animation graphic below of the air conditioning system. It is a simple and cheap Savonius rotor windmill driving a simple large rigid piston in cylinder to MODERATELY COMPRESS natural air, in this case into HALF the volume. The ideal gas laws show that when natural air which starts out at a deep soil 52°F temperature is COMPRESSED into half its volume, the air HEATS UP to around 215°F temperature! We picked the deep soil temperature as the LOWEST temperature of available air to draw into the cylinder. If the weather happened to be warmer, then the temperatures would be higher still.
The device for this purpose would NOT have the outlet pipe underground, and indeed, it would need to have very good (R-20 or better) thermal insulation around it. We would WANT it to get up near that 215°F and to STAY there! So we would now have very hot air inside a long 4" diameter pipe, which has excellent insulation surrounding it. We then put a 3/4" copper tubing inside the middle of that hot air, and send pure water INSIDE that copper pipe. That water would gradually HEAT UP from the extremely hot air surrounding it! Presto, a supply of hot water for any faucet or shower or bathtub!
WHY does this work? Well, you have probably seen an air compressor. The head and block of that compressor has cooling fins all around it, but it still gets so hot that you can seriously burn your finger by touching it. That heat is ENTIRELY due to the air getting hotter as it gets compressed! Specifically, the actual Ideal Gas Law which applies for air when it is being adiabatically compressed, is T2 / T1 = (V1 / V2)0.4. Temperatures are measured in absolute scales. So you can confirm that if we compress the air to HALF the original volume, this simple formula shows the 215°F resulting temperature we mentioned above.
The actual temperature you would get depends on diameter of pipes and if you are using a storage tank and other such things, but the point is that a temp of 215°F is surprisingly easy to produce, and WITHOUT needing any fire or flame! Down below, we describe how to overcome the effects of the volume of a storage tank and the piping.
The QUANTITY of hot water depends on how long the pipe is and how much copper tubing is inside it. It MIGHT even be possible to combine this water heater with a standard hot water TANK to then have a supply of 40 gallons or whatever of hot water for reliable usage. It also strikes me as possible to have each of the hot water pipes to kitchen and bathroom faucets fed by separate co-axial heater tubes, so that INSTANT hot water would come out of any faucet. (I HATE waiting for the heated water from a tank to have to run through the house piping to get to where I am waiting for it!)
It might also be possible to create that heat due to the air compression, use it to heat water up, and THEN send that compressed air down into an underground tube or tank (as described below regarding food refrigeration) and therefore get yet another benefit from the simple device! Cool?
Yet another possibility is to focus on the compression-heating effect to create WARM AIR to try to heat a house! I will probably try that in the process of doing these other things, but I personally doubt that the power that can be captured by a Savonius Rotor would be sufficient enough to do significant heating of a room or house. Heating domestic hot water? Easy! Doing food refrigeration and freezing? Easy. Bigger scale energy needs require greater amounts of energy to start with, per the Conservation of Energy!
for the explanation and simple plans to build an inexpensive system provide plenty of safe (distilled) drinking water. If there is NOT available any well or river or other source of water around, the systems can usually provide around 10 gallons per day in US climates. The systems are easily enhanced to provide larger quantities of water. If rainwater is collected, it can be processed. Also contaminated river water can, or most other supplies of water, to provide as much as 250 gallons of ABSOLUTELY PURE (distilled) water per day. And if you happen to be near an ocean, the second link above is the same system used to desalinate seawater (or nearly any other source of water, such as gray water or even sewage), to provide absolutely pure water to drink or bathe in.
When people try to go off-grid, they often do not realize that if they need to have a deep well drilled, the pump then necessary uses a LOT of electricity in raising that water a thousand feet or whatever! On top of that fact is that often the giant trucks that carry the well drilling equipment often cannot get to really remote locations, and huge extra charges are then involved in boring the well in the first place. These systems presented here do not require boring a well or even having a powerful pump. They actually remove humidity from the atmosphere, in amazing quantities!
(This system was invented and Engineered in 2007. We had previously invented a rather different system to provide pure drinking water using any source of water, whether it was seawater, graywater, polluted river water or anything else, in 2004.) (It has been amazing that UNICEF and OXFAM and the other giant NGOs have had absolutely no interest in this and the earlier devices for this purpose. When the Boxing Day Tsunami killed hundreds of thousands of people, and eliminated safe water supplies for millions more, we and several similar small companies OFFERED to provide FREE SYSTEMS which could have immediately been sent to the damaged villages. We (and the other companies) were told to SELL the equipment we had and then to send them the money from those sales, so that THEY could then decide to allocate the money to buy what they, the "experts", decided was needed. Bureaucracy often drives me crazy, and that was a prime example. Several of our companies had systems which were ready to be crated up to be shipped to Indonesia, where the people there would then have had good access to excellent water within a few days. Instead, UNICEF and OXFAM bought bottled water from companies in the US for several dollars per bottle, paid a fortune to ship them around the world to get there, and then handed them out for a few days, until their supplies of bottled water ran out. The local people then had NO good supplies of water for at least a year afterward, and many still do not, even several years later. Why can't bureaucrats comprehend common sense?)
Free Home Air Conditioning (1978, December 2000)
A guideline is the temperature of the deep soil (four feet deep) in any location. There are two easy ways to determine this number. One is by adding the day and night average winter temperatures and the day and night average summer temperatures and dividing by four to get an overall average temperature for that climate. The deep soil will be very near that temperature. The second method is to pump some water up from a well and measure its temperature, which should be close to that same number. If that number is lower than 60°F (16°C), the Free A/C should work fine, including removing humidity from the air. If it is up to about 70°F (21°C), it can provide moderate cooling but probably no dehumidification, meaning a dehumidifier would be needed OR the Hot Climate device below could be used. If the deep soil is above 70°F (21°C), the Hot Climate device will likely be a good idea, although the Free A/C can still PARTIALLY cool down an extremely hot house or room, down to near the deep soil temperature.
That presentation is VERY long and comprehensive, in order to include all the necessary information for understanding the concept and the system and for actually building it for a few hundred dollars total cost. It essentially is a Technologically Engineered version of a natural cave, where summer coolness is natural. However, in the realization that some people have applications that are in peculiar climates or soils or the building is a giant tennis club complex, we made available a Technical Packet of the Engineering data and equations. For that, from the start in November 2000, we have asked that a person give an anonymous $250 to any worthy Charity such as a Soup Kitchen or Homeless Shelter or Food Bank or others. Amazingly, over 5,900 people have requested the Technical Packet so far! Assuming they all gave the requested gifts, that means that as a side effect of this Free A/C, nearly $1,500,000 has been given to needy causes! Cool! In many ways!
Specifically, this drawing is for an EXTREMELY hot climate, where we chose a 4 PSIG pressure differential in order to produce really cool air no matter how hot the air or building or ground is. Because of that relatively high pressure differential and the large amount of cool air needed for air conditioning, this configuration would require a substantial amount of power, from the wind or from a river or waterfall. In a less severe climate, or if less cooling boost is needed for the standard Free A/C, it might be possible to change the crank offset to 1.9" instead of the 3.8" we chose here. That would create a lower pressure differential, around 2 PSIG instead of the 4 PSIG we selected here, and also less air would be processed, making the power need from the Savonius Rotor far less. For a climate where the soil is only moderately warmer than usable for the Free A/C, such a change, or even less yet, might make sense. The basic construction would still be identical.
Artwork provided by Niranjan Boteju
(If you have taken a long time reading the above, this animation may have stopped working, and you might REFRESH your browser to see it all working.)
This drawn example pumps about 1.5 cubic feet of air in each stroke, around 50 times per minute, so it would provide about 75 cubic feet of cool air per minute, not a lot but useful, because it can be quite cool. The maximum pressure that this arrangement could produce (due to the ratio of the fraction of the drum volume at max and min, 32.5"/25.75") is around 4 PSIG. When air at that pressure is released to atmospheric pressure (inside a house), it naturally expands and cools by about 41°F. That process is technically called the Joule-Thompson Effect, an application of the Ideal Gas Law, where the air is throttled through a narrow escape path. (You HAVE already seen this, big time, in using a carbon dioxide fire extinguisher! The CO2 inside the tank is at a pressure, and essentially at room temperature. When you squeeze the release trigger, carbon dioxide is released through a tiny throttle orifice. You have noticed both how COLD the escaping carbon dioxide it but also that white ice crystals form around the orifice due to the amazingly cold escaping gas! We do NOT want or need the high pressures of such fire extinguishers, but the concept is the same.
On a 120°F afternoon in India, and the deep soil temperature is 85°F, this system could fill an underground tank with some SLIGHTLY compressed air (4 PSIG) which was first heated due to the compression but then cooled to 85°F due to contact with the deep soil. When that compressed air gets released (inside a house, that Joule-Thompson Effect) that air can cool by an additional 41°F, and that air arrives in the house as cool as 44°F. Since the air is at below 60°F, humidity condenses in that air so that the house air is not only cooled but dehumidified, exactly what traditional air conditioners do!
A modest supply of air at 44°F can easily cool and dehumidify the air of one or two rooms in a very hot house on a 120°F afternoon in India! Duplicate units or one of larger size and capacity could easily cool and dehumidify the air of ANY entire house!
Notice that this is a RECIRCULATING system, where the house air is re-used over and over. A popular habit in some countries such as India is to use Single-Pass Ventilation, where windows stay open and any cooling effect is immediately discarded, which is extremely wasteful of cooling effect! All advanced Air Conditioning systems recirculate the house air, as does ours. Instead of having to start with outdoor air at 120°F, it is far easier and more efficient to start with air from inside the house which may only be at 95°F.
There is an extremely wide range of climates and house sizes for which this system might be used. If you choose to just make something similar to this drawing, it will certainly work, but some Engineering calculations can be useful to make sure to build a system which works GREAT!
Some numbers: The device as drawn processes 1.25 cubic feet of air every second, and compresses that air by 4 PSI or 576 pounds per square foot. Multiplying, we see that 720 ft-lb/sec of mechanical power is involved. This can be converted to 1.3 horsepower or 980 watts of mechanical power. One PSI is equal to about 6900 nt/m2 (or Pascals) and 1.25 cubic feet of air is equal to about 0.0354 m3. Multiplying 0.0354 * 6900 * 4 equals 977 Watts, confirming our numbers. A relatively large Savonius Rotor would need to be built to capture this much wind power. At the other end of the system, we have 75 cfm of air or about 360 pounds of air per hour that is released to capture around 41°F temperature differential from the house's air. Air has a thermal capacity of about 0.25 Btu/pound. Multiplying, this is around 4,000 Btu/hr of cooling. That is not an enormous amount but it certainly could cool a room or two very well. If the deep soil is cooler than 85°F, the cooling performance can be much greater.
The local average windspeed determines how much power there is in the wind's motion. You want to make sure that the windmill is powerful enough to compress the air with the winds that are usually around! For example, in the US, a common windspeed is around 10 mph, and that speed wind contains around 5 watts of power per square foot of wind area. This can indicate how LARGE a Savonius rotor or other power source might be necessary. The pressure that the piston has to push against and the area of the 22" piston and the rate at which the piston is moved, determine how much power is used in compressing the air. In the process of compressing that air to this example 4 PSIG (in a standard adiabatic process), the Ideal Gas Laws show that the air naturally heats up by around 42°F in temperature, up to about 127°F. Additional cooling power is gained by then letting that self-warmed compressed air cool off in the underground pipe and storage tank (down to around 85°F), and then we have already noted that releasing the pressure causes the air to drop down to around 44°F in being released inside the house. You can see how it is possible to estimate how much air conditioning effect can be obtained just from some math calculations!
I CHOSE the dimension of the crank offset of about 3.4" to set the 6.8" distance the piston moves back and forth inside the drum cylinder. Note that the drum does NOT have a lid on the back side. I CHOSE the length of the connecting rod to set the RATIO of the two volumes of air inside the drum cylinder (32.6" / 25.75"), to establish the (maximum) PRESSURE created and therefore the added cooling effect when the partially-cooled-by-the-deep-soil compressed air is released into the house. I strongly suggest doing a little simple math if you intend to change any of the dimensions shown here.
Please notice that BOTH of the two large pipes connected (toward the right in the drawing) are ALWAYS underground, in order to gain cooling effects from the deep soil, and both go completely to the house and inside it. The INTAKE pipe draws hot air from INSIDE the house, up near the ceiling, at say 95°F, which gets cooled to the deep soil temperature of 85°F in that first (INTAKE) underground pipe. The compression in the drum cylinder causes that air to heat up to around 127°F. As that self-warmed air passes through the OUTLET underground pipe, it cools back down to around 85°F again, but it is now compressed. There CAN be some additional benefit of burying a storage tank in that OUTLET pipe near the house, in order to give that air some extra time to cool down to the deep soil, but that can depend on many variables. Once the OUTLET pipe is INSIDE the house, it needs to be controlled by a pressure release throttling valve, which can also be a reduction in diameter of the pipe and a solenoid valve. A wall thermostat could control that solenoid valve to then only release the very cool air when a room called for it.
This hot climate A/C is actually a variant of the Refrigeration and Freezer system discussed below. This modified A/C system was invented in 2008.
Air conditioning is a process that uses up a good deal of power (as you may have noted by the powerful compressor running outside your house which eats up massive amounts of electricity). So the A/C version here is likely to require a larger Savonius Rotor than old 55-gallon drum which is adequate for the refrigeration or freezing usage, is likely not large enough for significant A/C production. Below, we describe how simple changes can be made to change the crank throw and the connecting rod length to greatly change the capacity and performance of this system.
The refrigeration system involves underground tubes, but also some added components that enhance the effects. It is actually based on one of the first inventions of refrigeration around 1844, by a man named Gorrie. Some external power is necessary, which is obtained from either a simple and inexpensive Savonius Rotor windmill or from flowing or falling water. Then there is some mechanism that acts as a low pressure air compressor. Here is a drawing of the general arrangement. Many variations are possible.
Artwork provided by Niranjan Boteju
This drawn example, which involves a SMALLER 20-gallon steel drum, pumps about 0.6 cubic feet of air in each stroke, 30 times per minute, so it would provide about 18 cubic feet of cold enough air per minute for usage in a refrigerator. We will consider an example here of deep soil at around 65°F. The maximum pressure that this arrangement could produce (due to the ratio of the fraction of the drum volume at max and min, 18.6" / 14.7") is around 4 PSIG. When air at that pressure is released to atmospheric pressure, by that Joule-Thompson Effect of releasing the pressure through a throttle valve, it drops by about 41°F. No matter what the air temperature or deep soil temperature or house air temperature might be, air that is drawn FROM the refrigerator box should not be above around 40°F. The deep soil temperature is generally of no use whatever for this INTAKE air as it is already cooler than the deep soil is, as it likely would WARM the air up, just the reverse of what we want! Therefore, we use SMALLER DIAMETER 2" PIPES for this (as compared with the A/C presented above) AND that INTAKE pipe needs to have GOOD thermal insulation around it. The (slightly) compressed air gets released (inside a refrigerator box) and that air can cool (as it expands) by an additional 41°F. After it is compressed to our 4 PSIG pressure and then cooled by contact with deep soil, the compressed air should get down near 65°F and then drop by that additional 41°F due to the expansion, to arrive in the refrigerator as cool as 24°F. That is cool enough to refrigerate food safely in the 35°F to 40°F temperature range.
The PRESSURE needed for the refrigeration is dependent on the SOIL TEMPERATURE. As a guide, if your soil temperature is lower than about 65°F, 4 PSIG is fine. Up to 75°F, a longer connecting rod should be used so that a higher pressure of 5 PSIG is created (nothing else needs to be changed). Up to about 85°F soil temperature, 6 PSIG should be created. The reason for this difference is that the goal is to provide air at around 32°F, and that requires different amounts of differential cooling down from the deep soil temperature that we have available in a specific location.
In other words, in nearly any location in the US, if you choose to just make something similar to this drawing, to create a max of 4 PSIG, it will certainly work well.
Some numbers: The device as drawn processes 0.6 cubic feet of air per stroke or 0.3 cubic feet every second, and compresses that air by 4 PSI or 576 pounds per square foot. Multiplying, we see that 170 ft-lb/sec of mechanical power is involved. This can be converted to 0.3 horsepower or 230 watts of mechanical power. One PSI is equal to about 6900 nt/m2 (or Pascals) and 0.3 cubic feet of air is equal to about 0.0085 m3. Multiplying 0.0085 * 6900 * 4 equals 234 Watts, confirming our numbers. A relatively common-sized Savonius Rotor could capture this much wind power. At the other end of the system, we have 18 cfm of air or about 85 pounds of air per hour that is released INSIDE THE REFRIGERATOR BOX to capture around 41°F temperature differential from the refrigerator's air. Air has a thermal capacity of about 0.25 Btu/pound. Multiplying, this is around 900 Btu/hr of cooling. That is not an enormous amount but it certainly could cool a refrigerator full of food very well.
The local average windspeed is likely to be sufficient to produce the limited amount of cooling needed inside a refrigerator box, as long as the door of the refrigerator was generally kept closed, so that a crude 55-gallon-drum Savonius Rotor should be sufficient. The pressure that the piston has to push against and the area of the 18" piston and the rate at which the piston is moved is moderate, and those parameters determine how much power is used in compressing the air. In the process of compressing that air to 4 PSIG, the Ideal Gas Laws show that the air heats up by around 42°F in temperature, up from the initial 40°F to about 82°F. This newly-warmed compressed air is then cooled off in the underground pipe and storage tank (down to around the local deep soil temperature, which is 52°F near Chicago but will be assumed to be 65°F in this example for a more southerly location). So now we have a supply of air compressed to 4 PSIG which has cooled in the OUTLET pipe (and storage tank, which might be an old hot water heater tank), which is NOT insulated such that it can COOL down to the soil temperature, so the air drops to about the deep soil temperature of 65°F. We have already noted that releasing the pressure causes the air to drop down by about 41°F, to around 24°F, in being released inside the refrigerator box.
I CHOSE the dimension of the crank offset of about two inches to set the 4" distance the piston moves back and forth inside the drum cylinder. Note that the drum does NOT have a lid on the back side. I CHOSE the length of the connecting rod to set the RATIO of the two volumes of air inside the drum cylinder (18.6" / 14.7"), to establish the (maximum) PRESSURE created and therefore the additional cooling effect when the compressed air is released.
Notice that BOTH of the two pipes connected (toward the right in the drawing) are ALWAYS underground and both go completely to the house and inside it. Also that the INTAKE pipe is wrapped with thermal insulation. The INTAKE pipe draws relatively warm air (maybe 40°F) from INSIDE the upper part of the refrigerator box. The thermal insulation around the INTAKE pipe keeps that somewhat cool air from being heated by the soil which is likely warmer than it is. The compression in the drum cylinder causes that air to self-heat by the 42°F we have already discussed, up to around 82°F. As that self-warmed air passes through the OUTLET underground pipe, it cools back down to around 65°F of the deep soil again, but it is now compressed. There CAN be some additional benefit of burying a storage tank, such as an old hot water heater tank, in that OUTLET pipe near the house, in order to give that air some extra time to cool down to the deep soil temperature, but that need can depend on many variables and many locations will not need it. Once the OUTLET pipe is INSIDE the house, it needs to be controlled by a solenoid valve, which can also be a reduction in diameter of the pipe. The existing temperature thermostat inside the refrigerator could then automatically control that solenoid valve to then only release the very cool (24°F) air when the refrigerator thermostat called for it.
A common 55-gallon drum Savonius Rotor should be adequate for the refrigeration or freezing usage, for most climates.
For all of these drum-compressor systems, the ACTUAL pressure you will create will be less than we have calculated! How much less depends on specifically what you build! Here is why. We used the ratio of the volume INSIDE the drum under the piston to calculate the pressure ratio and therefore the maximum final pressure. That is not actually the case! The OUTLET flapper valve does not actually separate the volume of the drum from the volume of the pipe connected to it, including any storage tank you might include, all the way up to the solenoid valve that can release the air pressure. Fortunately, there is an extremely simple way to correct for this! You could INCREASE the dimension of the crank on the Savonius Rotor shaft (and you will then also have to change the connecting rod length to cause the RETRACTED position of the piston to be the same as before). These are simple changes which you could make at a later date if you so decided that they were necessary. There are only two concerns about doing this. (1) If you are using a drum which has ridges for structural strength, you can't have the piston try to pass by such a ridge during its movement, both for the air leakage which would occur and for mechanical problems of the piston possibly getting stuck in that groove! (2) If you use a storage tank that is LARGER in volume than the drum-compressor is AND you operate it to produce a high pressure, the movements of the piston might get very extreme.
Note that TWO or more of these systems could feed compressed air into the same buried storage tank and house. Regarding providing Air Conditioning, this might be a simpler solution than in building a giant Savonius and drum-compressor!
For doing the actual calculations, you would need to use ABSOLUTE temperatures, based on -459°F. Therefore, a deep soil temperature of 65°F [like for Alabama] can also be described as being 524°R, in a temperature system based on absolute zero).
You have dug a pit a few feet deep where you have securely mounted the (horizontal) steel drum and also the mounting supports for the Savonius Rotor windmill, completely below the surface of the ground! We create a crude low-pressure air compressor, and can even use a disk of plywood for the piston, which we then surround with weatherstripping to reduce air loss past the piston. Our crude compressor only has two Strokes, Intake and Compression/Exhaust.
You will then simply dig at least one trench to bury maybe 100 feet of the appropriate diameter PVC or metal pipe. (If you are going to do A/C, you may need to dig several [parallel] trenches and put several PVC pipes in, to be able to provide the amount of airflow necessary for cooling a whole house.)
The entrance of that/those pipe(s) is/are connected (underground) to the house/refrigerator air. So step one is to COOL the (house) air (or NOT HEAT the refrigerator air!) in the (first) underground tube(s) down to near the deep soil temperature
The exit of that/those PVC pipe(s) is/are connected to send the air past the INTAKE flapper valve inside the drum-cylinder. As the piston recedes inside the cylinder, it causes a suction effect which causes the flapper valve to be pulled open, allowing the incoming air to enter. The Flapper Valve can be as simple as an eight-inch square piece of thin rubber such as from an automobile inner tube, with two pieces of thin aluminum metal attached to it. A STRIP of aluminum is BOLTED to the drum end, ABOVE the pipe entrance, squeezing the flexible rubber between. This allows the rubber piece to HANG FREE and block off the opening due to gravity. The other piece of aluminum is mounted to the BACK of the hanging area, possibly with strong adhesive, and being a CIRCLE of maybe 6" diameter. The purpose of this piece is to keep the rubber FLAT, so it would not get blown open by air pressure! An additional RING of rubber might be attached (by adhesives) AROUND THE OPENING in the drum end, to even better ensure air-tightness of the flapper valve when it is closed.
The Savonius windmill, spinning up above at around one time per second, turns the simple crankshaft lever. The two Flapper Valves then automatically open and close as necessary. The piston never moves at even walking speed, so friction and wear and tear against the drum walls is minimal.
This then creates slightly compressed air, which gets sent into the second pipe. The pressure begins very low, but as long as there is wind to blow, pressure would keep being added into the OUTLET pipe (and buried storage tank), as long as air was being provided at least as fast as it was being removed for usage. Here is the first really important part here. In the process of compressing air, it heats up! This is a natural situation which always occurs. So Step two is in compressing the air in the drum/compressor, to CAUSE it to heat up like that! Air is pretty close to what is called an Ideal Gas regarding such things. This is technically called an isentropic adiabatic compression, because it does not change the Entropy of the air in the process of the compression. There are simple and standard equations (provided below) that can calculate the temperature the (compressed) air gets up to, due to this effect of the adiabatic compression.
Step Three is in sending that self-warmed air through a second underground tube, to again let it cool down to the deep soil temperature.
When you RELEASE that pressure, the same formulas apply again! But this time, since we are releasing the pressure, the air COOLS DOWN. This is the fourth and final step in the process, where cool or cold air is produced!
FYI, the science of the description above is nearly EXACTLY what happens in your home A/C system and your own refrigerator and freezer! We are just describing very low-tech ways of accomplishing each of those steps, without having to use Freon or Ammonia or other refrigerants. In case you are curious, before Freon was discovered, all refrigeration and freezing equipment used either ammonia (which is a very dangerous material and not like the very diluted stuff you use at home) or compressed-air refrigeration. So this is not as though we are recommending some bizarre concept! It is actually generally considered an OBSOLETE concept, as THIS concept of refrigeration was actually invented in 1844 by a guy named John Gorrie! Compressed-air refrigeration was used fairly broadly for the rest of the 1800s and into the 1900s, but when Ammonia refrigeration was developed, it rapidly took over the bulk of the refrigeration market. Unfortunately, when such Ammonia equipment would fail and release concentrated Ammonia gas, people tended to die! So safer substitutes, generally the family of Freon refrigerants, were invented! (Freon or ammonia or any other refrigerant has one advantage over our type of air-based refrigeration. During the phase just after the compression, the refrigerant CHANGES STATE from being a compressed gas to becoming a liquid. The heat exchanger which does this is therefore called the Condenser! That change-of-state involves a great deal of energy being removed from the refrigerant, far more than just cooling a gas or liquid can give up. This then allows GREATER refrigeration effect when that compressed [and cooled] liquid refrigerant later has its pressure released.) Our theme here is that YOU can accomplish the SAME refrigeration or freezing processes with a low-tech crude cylinder air-pump that you can make. Yes, you will be using Gorrie's technology of 160 years ago, but it is certainly WELL proven! And it works excellently! You are free to spend $700 on a conventional refrigerator that forever uses a lot of electricity! Gorrie's and our approach is DIRT cheap (pun intended!) and it uses very little external power, which a crude Savonius rotor windmill can provide. Ditto for Third World people who have no available electricity and do not have $700 to buy a new refrigerator anyway! Finally, you may have thought ahead and considered using a furnace BLOWER or a FAN to do the compression. Won't work! Blowers and fans are great at MOVING air, but they are lousy at COMPRESSING it. Some (expensive) Industrial blowers can develop 1 PSI or 2 PSI pressure, but we will see below that that is not enough for our needs.
If you have ever used a carbon dioxide fire extinguisher, you know that frost forms around the outlet, and the valve can even freeze up and clog! It is NOT because carbon dioxide is naturally cold or anything! But it was COMPRESSED when it was put into that fire extinguisher. When that pressure is released during use, the rapidly expanding carbon dioxide that comes out can become extremely cold, due to this exact same Ideal Gas effect we are discussing here (in our final phase of the releasing of the pressure).
(For now, we are still discussing here a moderate climate where the deep soil is around 65°F [like maybe Alabama]). Say that we only compress the air to just around 8 PSIG. This is REALLY easy to do! (With just your mouth, you can provide around 2 PSIG pressure to blow up balloons, etc, so 8 PSIG is a very minimal pressure to be producing with the drum-compressor.). After this minimal compression, the air only rises to around 599°R or 140°F. This rather warm air goes through the second underground tube system and is cooled back down to near the 65°F of the deep soil. Remember that our air cannot CONDENSE, but it accomplishes the same effect in that second underground tube as a Condenser does with a refrigerant. When we later release that pressure, we find that the air gets cooled by around 65°F. For this climate being discussed, this would result in air at 0°F, which would be excellent for sending into a food freezer.
But in a hotter climate, as in an African jungle where the ground temperature is near 100°F, this would result in air at around 35°F, suitable for sending into a refrigeration box, not cold enough to create ice, but still plenty cold enough to preserve food. For that extremely hot African climate, a slightly higher compression would be necessary to provide freezing of food. We will consider a variety of other climates and applications below.
You might see from this example that you may want to select a specific pressure for the system depending on the climate that is present and the application you intend to accomplish. That pressure can be established by choosing how much air you will run through this system to compress, AND by how fast you will be releasing that compressed air at the other end to produce the desired cooling effect. It NEVER hurts to over-design a system, where it either does or can provide more compressed air at higher pressure than you actually need, because you can always control the actual cooling effect by adjusting the rate that air is released in the refrigerated chamber. Below are the formulas and a bunch of examples to guide you regarding this stuff.
You could even provide less air conditioning! You might choose 2 PSIG pressure. The compressed 85°F air from the house warms by about 17°F to around 102°F due to being compressed in the drum-cylinder, and then drops back down to the 65°F deep soil temperature in the outlet tube, and then drops down an additional around 18°F when the pressure is released, down to around 47°F. That is low enough (below 60°F) to cause nearly all the water vapor in that air to condense, which dehumidifies the air to the desired level. That air would then be sent directly back into the house (where it had initially come from!) as cooled and dehumidified air!
All three of these functions will work fine no matter how hot the climate is! So any house or building anywhere in the world can have refrigeration, a food freezer, and air conditioning, without using any electric power at all! Even a remote hut in a jungle near the Equator can therefore have air conditioning! And more importantly, safe food preservation! The only difference, as we will soon see is regarding the pressure we need to compress the air to!
We are needing a VERY MINIMAL compressing of air (and nothing else), and so there are many alternate ways of doing this moderate air compression. You could find a piece of large diameter metal pipe or sturdy tubing, and make the cylinder-pump out of that instead of using a drum
You might be surprised to learn that MANY commercial air compressors use such flapper valves to allow air into and out of the compressor cylinder, and they can generally produce more than 100 PSI of pressure! Your homemade flapper valves may not be that excellent, but they do not need to be, because the pressure you will need are far lower.
These devices are simple enough and they are made of items that may be available even in Third World locations.
T2/T1 = (P2/P1)(n-1)/n
n is a number that is specific to a type of gas and the process occurring. For air in isentropic expansion or compression, n is very close to 1.4. This results in that exponent being around 0.287.
T2/T1 = (P2/P1)0.287
All you need to remember is that these are ABSOLUTE pressures and temperatures, meaning that a normal day might start out with 15 PSI air (atmospheric pressure) (called 15 PSIA, which is also 0 PSIG, or gauge pressure) and 527°R temperature (the absolute temperature that is the same as 68°F.)
so the fraction is
Because of the exponent, the ratio of the pressures is therefore
Since the ambient air pressure is 15 PSIA, this means that the bellows or cylinder would need to produce around 15 * 2.245 or 34 PSIA which is also 19 PSIG. This can be hard to achieve, especially with bellows. So for full food freezing when the air temperature is 120°F, the underground intake tunnel may be necessary. In that case if the 120°F air is cooled to the 80°F deep soil temperature before it gets compressed, and we would have a different calculation, where the fraction would be:
so the fraction is
Because of the exponent, the ratio of the pressures is therefore
This results in needing only 15 * 1.75 or 26 PSIA or 11 PSIG rather than 19 PSIG to get the needed freezing. This is a significant improvement, and it is ENTIRELY due to the effect of the INTAKE DUCT cooling the air BEFORE it is compressed! It still would be solid freezing food at 0°F on a day when the air temp is 120°F, an impressive accomplishment!
so the fraction is
Because of the exponent, the ratio of the pressures is therefore
This results in only needing 15 * 1.59 or 24 PSIA which is 9 PSIG to be provided by the bellows or cylinder to provide the needed refrigeration.
And finally, we can consider using the underground intake tunnel for this refrigeration. In that case if the 100°F air is cooled to 70°F before it gets compressed, we would have a different calculation, where the fraction would be
so the left fraction is
Because of the exponent, the ratio of the pressures is therefore
This results in needing only 15 * 1.31 or 19.5 PSIA which is 4.5 PSIG where a bellows or a simple cylinder pump can easily provide that for the desired refrigeration.
We have not really discussed here the AMOUNT OF ENERGY involved. THAT is the analysis which can determine just how large and powerful the air pump must be. For food preservation by refrigeration or freezing, we feel those calculations should be unnecessary here, as the dimensions and figures described above should all be fine for any climate (for one family). But even if it should turn out that not quite enough refrigeration is obtained for an application in Indonesia, we would then simply recommend making a duplicate second system to provide the additional refrigeration needed. (The calculations can be fairly involved.) For full air-conditioning applications, those calculations are likely necessary to do, and a local Engineer should be found to do them for you. They involve first determining the total amount of energy (actually power) that would be required for the cooling effect desired. Then a multiplier is used to account for the fact that the different processes here are not perfectly efficient. This then gives the amount of power that would be needed to be removed in the phase where heat is lost from the compressed, heated air in the (second) underground tube, and you can then work backwards to calculate the amount of power required in compressing the air in the first place.)
However, the food cooks rather slowly, much like a Slow-Cooker or a Crock-Pot.
So, as either a side-benefit of the HG 3a heating the home, or as an independent system exclusively to service the greenhouse, the HG 3a unit can enable a small greenhouse to produce five times the fruits and vegetables during a normal growing season, in addition to the possibility of heating the greenhouse all year and thereby producing far more crops yet. Generally, really small greenhouses are hardly worth the effort as they produce so little, but if that same small greenhouse can produce five times as much, or possibly ten times as much food as normally, the whole concept of self-sufficiency regarding food becomes far more realistic.
Now, I realize that some people might be scared at the idea of going into a greenhouse which had a carbon dioxide concentration of three times the outdoor natural of around 388 ppmv. I suppose that 1100 ppmv might SOUND scary! But carbon dioxide is NOT dangerous at all, and you will likely be very surprised to learn that in YOUR house during the winter, the relatively closed house tends to accumulate the carbon dioxide that you exhale all winter, along with some more produced when your (gas) kitchen stove cooks. How high does it get? 4,000 ppmv is not unusual, and is NOT DANGEROUS! If you have ever attended a really long lecture in a really old auditorium, have you ever gotten drowsy? The reason might have been more than just the boring subject! Thousands of people exhaling carbon dioxide in an auditorium that has a poor air circulation system can have 10,000 ppmv of carbon dioxide late in the lecture! And when amounts get that high, the most common first symptom is drowsiness!
It occurs to me that there is an entirely different subject which I am not aware any scientist has ever researched! Lots of people grow house plants. Some of those plants seem to grow amazingly well DURING THE WINTER, behind glass windows! The FACT that the house air likely contains (wonderful?) added carbon dioxide MIGHT be providing this effect for those house plants!
You have already figured out the rest! A cold sidewalk which is covered by ice or snow at 32°F or lower normally needs YOU (or a teenaged son!) to go out to shovel it clear. But by opening that damper, your house heating system, whether a conventional furnace, an HG 3a device or the NorthWarm Version 1 Totally Solar Heated house (heat storage in that case) can feed warm air through those tubes. That warms the ground around the tubes. Heat naturally rises so the concrete sidewalk immediately above it quickly warms up. Getting the concrete up to 50°F is easy and does not take too much house heat. The snow and ice laying on top of that nicely warm concrete sidewalk quickly melts!
In fact, if you plan ahead maybe an hour, you can have the sidewalk ALREADY at 50°F as the snow or sleet begins to fall, and it IMMEDIATELY MELTS and your sidewalk REMAINS CLEAR of any snow or ice. Not even just avoiding having to shovel snow, but absolutely ice-free sidewalks that NO visitor might slip and fall on and sue you!
Pretty cool, huh? Or WARM, actually!
Late in 2010, I discovered what I consider an even better version of this! NO HEAT FROM THE HOUSE IS EVEN NECESSARY OR WASTED!
NO ducts from the house heating system here! Find some nearby Farmer who has a tractor with a posthole auger on it, and with compliments, possibly money and possibly beer, have him drive his tractor to your building site! He would bore what seem like a LOT of postholes, in either two or three rows (depending on how wide your sidewalk is) and every foot or two along its whole length.
Because YOU are then going do DROP into each of those holes a VERY SIMPLE and VERY CHEAP "thermosiphon heat exchanger" into each of them, and cover them all up with a few inches of dirt or gravel ballast for the sidewalk. By the time the concrete truck shows up to pour the sidewalk, they would never know that there is anything underneath!
Why do this?
Have you figured it out? In a climate like Chicago's, the DEEP SOIL never drops to below about 52°F during the winter. You are going to make simple HOLLOW TUBES with END CAPS to drop into each hole. There is a natural process called Thermosiphoning where WARM air or water RISES and COOLER air or water SINKS. Inside each tube, the air near the bottom is HEATED by the 52#176;F soil surrounding the tube (WARM) and up near the top the air inside the tube is COOLED by the winter cold surface temperatures (COOL), including the concrete sidewalk.
Thermosiphon immediately occurs (just like in the pot of water you boil on a kitchen stove) and the net effect is that HEAT from the deep 52#176;F soil gets moved to warming air inside the top of the tube, and therefore the soil and concrete sidewalk above it.
The result of this is that YOUR SIDEWALK then ALWAYS stays near 52#176;F through the entire winter, constantly and continuously being warmed from the Earth's enormous supply of heat!
You then have that situation of the pre-heated sidewalk, where snow or sleet immediately melts as it falls! Snow accumulates on your yard on both sides, and can become 12" inches deep, but the sidewalk will ALWAYS remain snow-less and ice-less!
Details? For a sidewalk, in anywhere except northern Alaska, Siberia or Antarctica, 4" PVC or iron pipe seems to be fine. Iron pipe end caps cause that choice to be a little more expensive, but if you have a welding machine, you could weld on end disks of steel onto the pipe. In fact, the TOP end cap might then be an 8" square plate of 1/4" plate steel, to create an even LARGER SURFACE of the warmth to more widely warm the sidewalk which will later be above it.
How deep, or equivalently, how long should these things be? Certainly THREE FEET is a minimal, even for a sidewalk. No more than four or five feet for any sidewalk application. The Tractor posthole borer (without some simple modifications to go deeper) can commonly only bore holes which are three or four feet deep, so you might check with the Farmer first before making them.
IF you want to go top-drawer, you could complicate things a bit. It turns out that this arrangement causes thermosiphoning that is somewhat disorganized inside the tubes, and therefore less of overall efficiency in transferring heat up to the sidewalk. For a sidewalk, I do NOT see the following improvement to be necessary! But a smaller tube (2" diameter PVC or iron pipe) can be installed INSIDE each tube, centered and about four or six inches SHORTER than the main tube is. This allows the heated air to rise through an OUTER passageway, where it is also exposed to sidewalls which are somewhat warm, and the cool air at the top sinks back down through the smaller central tube passageway. Thermosiphoning works a LOT better this way! That inner tube must NOT go all the way to either the top or bottom, and needs to be HUNG to permit easy and smooth airflow.
To make a driveway self-melting, I recommend LARGER tubes, 8" in diameter and WITH the central smaller tube inside, AND longer, and therefore deeper. The posthole auger needs to then have that modification to be able to bore deeper holes. And the holes can be a little farther apart, where I consider a grid of holes two feet apart in both directions should be fine. I consider a MINIMUM of 5 feet and an ideal 8 feet deep to be the goal. PVC is not available at reasonable prices in such diameter, so I recommend buying several 20-foot lengths of the 8" iron pipe or steel tubing (at least 1/4" thick) and using welding equipment to cut them to the lengths you will need and then weld on the two end plates of 1/4" steel, again with the top one being optionally square and larger, maybe 16" square. You will then also be able to weld in either an inner steel tube or at least support brackets to support an inner 4" PVC plastic tube.
Under a new garage concrete slab floor, the driveway guidelines are fine. The garage would then always stay at 52°F or warmer, so the engine will always start immediately and you will get into a car which is NOT horribly cold!
There ARE other applications of this which are obvious. EVERY city now spends MILLIONS OF DOLLARS to buy a bunch of snowplows to mount on the city's trucks and for the wages of the snowplow drivers and for many tons of road salt that they use up every winter to try to melt fallen snow. So each town and city can obviously SAVE MILLIONS OF DOLLARS normally spent that way (every year) by adding this snow-melting feature under every street as it is scheduled to be repaved.
By the way, since the PAVEMENT is then NEVER SUBJECTED TO FREEZING TEMPERATURES, NO POTHOLES COULD EVER FORM (which are not only ugly and dangerous but expensive to fill in and re-patch). And the LIFE OF THE PAVEMENT would certainly be MANY YEARS LONGER, meaning millions of dollars which now has to be budgeted for annual road repairs might be far less!
The City Attorney of every town and city should also love this, as there would then be VERY FEW VEHICLE ACCIDENTS since cars and trucks would not be sliding around on snow or ice covered roads! They simply cannot occur!
Those same City Attorneys should love the fact that pedestrians would be SUING THE TOWN LESS OFTEN, as they would not be falling due to slipping on public sidewalks or when crossing public roads!
Continuing this theme, city store owners would love being able to have a parking lot for their customers which would NEVER HAVE ANY SNOW OR ICE! MORE customers, eh? And walking FROM that ice-free parking spot to their store? Ice-free sidewalks, of course!
Not bad for a system which is invisible, requires NO fossil fuels ever, and which should last for more than 40 years, and which is not horribly expensive to install in the first place!
State Highway Departments might also want to try to make ice-free highways, although their situation might not be cost effective due to having to modify so many miles of roads.
But AIRPORTS definitely SHOULD install this IMMEDIATELY for their runways. Imagine an airliner being able to land on a PERFECTLY CLEAR AND DRY RUNWAY, even in a snowstorm or hailstorm or sleet storm? Only a 50-foot-width of the runway probably needs to be modified, but most of its length should be. Yes, that might be a fairly expensive project, BUT IT ONLY EVER HAS TO BE DONE ONCE in the airport's lifetime! The devices for an airport runway should be sturdier than I have otherwise described above.
These first several are simply a pattern of buried PVC or field tile tubes, buried at TWO different depths! One set of the tubes would be at a depth of at least three feet, so the surrounding temperature of the deep soil would be around 52°F or so. The other set of tubes would be just a few inches below a specific surface area. IN WINTER, the 52°F air going through those tubes (pushed by a blower of some sort) would WARM up the surface immediately above it.
See the general theme here? With some creative thought, there are an immense number of uses for nearly unlimited amounts of 52°F air. It is certainly excellent for air conditioning in the summer, but these examples show ways it can also be very useful in winter, even though it is at such a low temperature (52°F) that it might initially not seem useful at all!
Similarly, there are a lot of possible uses of the 150°F humid air that the HG 3a unit can provide. Etc.
There are also SUMMER applications for the two-sets-of-tubes concept. Here is a rather silly application, which will never be installed! I spent much of my adult life playing semi-pro volleyball, and a lot of that was in extremely hot beach sand! Most players wear little stockings to keep from burning their feet during long tournaments! Obviously, I realized that if this arrangement of two sets of underground tubes was installed, with one set four feet deep to capture the coolness of 52°F deep soil (or sand) and the other set just six inches deep, to run that cool air through the extremely hot (120°F) sand, we could have enjoyed far more pleasant tournaments! The expense of doing that is far too great for just the benefit of some sissy volleyball players not having to wear socks!
Imagine buying around 30 lengths (ten feet each) of 4" diameter PVC (thickwall) pipe, along with the couplings and solvent cement for it. They will be erected in a vertical tower, with guy wires for stability, or inside a drilled well or in a cave. At the very top of the PVC pipe would be a funnel that could collect rain from an area that might be 6 feet square. The bottom of the whole thing would be blocked off with an end cap, but first there would be a Tee and reducers to provide a small (1/2") connection to standard piping.
When this was first installed, it would be empty of water, right? But a first rain, of maybe 1/2" total rainfall, would funnel around 1.5 cubic feet of water (ten gallons) into the tube. That would fill around 18 feet of water into the tube. Very little water would ever evaporate from inside it, so after about 15 more rains, the entire 300 feet of the tube would be filled with water.
Why is this of any use?
Well, the PRESSURE in the water increases by about 15 PSI for each 32 feet of vertical water stacked up. So we have provided around 150 PSI of water pressure to the standard piping we attached at the bottom. This pressure could be brought to a nearby air tank arrangement, where a tank of compressed air at 150 PSI would then be available. This could power things like paint sprayers or automotive pneumatic tools or assorted other equipment.
The pressure of the water itself could be used for hydraulic equipment. It may be best to use the pressurized water to transfer pressure to hydraulic fluid (to avoid corrosion issues) but then some hydraulic equipment could be driven by this energy source!
As always, note that this is absolutely GREEN, and where the results are comparable to conventional air compressors or hydraulic pumps, but without needing any electricity to run any motors or any other fossil fuels to drive any other power supplies.
This is another concept which may not be of any great value. It's inclusion here is again mostly to show you that some creative thought can find wonderful new solutions to many problems of modern life!
So, try to avoid those few web-pages of mine, as I guess I was not as nice and friendly as I try to usually be!
One of the central aspects of attempting to be Independent is that you would not need a steady stream of repair people coming to fix things that had gone wrong! Another is that the ONLY sources of energy required for these things are absolutely GREEN! The HG 3a unit operates entirely on leaves and grasses that you can certainly find locally. The refrigeration and freezer and electricity recharging MIGHT require some wind power from some very simple and crude Savonius rotors (unless you have a waterfall nearby or other obvious source for mechanical power). The devices to provide safe drinking water are equally independent of any power-grid or LP gas delivery truck or any gasoline tank!
By the way, the HG 3a presentation mentions a FUTURE capability that I believe that system will be capable of, that of creating a substantial amount of electricity, possibly based on the Seebeck Effect of thermoelectric generation, but somewhat modified. If someone every finds a way to use an HG 3a for such a function, it might provide a whole new way of supplying us all with electricity, even maybe for future electric/battery-powered vehicles! But that is liable to be some years off! (I expect to add a variant HG 4a device sometime soon!)
So in my unique ways of finding unusual solutions to problems, I bought FOUR 42" flat screen TVs (which were on serious sale!) I used the mounting bolts that they intend for the TV to be hung from a wall, to instead hang them from the ceiling above my office desk, in a 2 x 2 pattern. So they covered around four feet by seven feet of ceiling area. I chose TVs which have the capability of accepting input signals from a computer, and so all four were connected to receive their video signals from the computer. I then used a set of four cheap cameras to record videos of four adjacent areas of the sky on a sunny summer day with white clouds going by!
I then LOOPED the videos to repeat, and so a wonderful blue sky with small white clouds are a wonderful distraction as a SKYLIGHT, even though it is not a skylight at all! I made a variety of videos, including a summer rainstorm, flocks of birds passing over, and others, which I can display as I wish. I actually made another video where the Sun slowly passes over, just like I was outside, but I have not watched that one because I am not sure that the very bright image of the sun might damage the flatscreen TV screen by being too bright.
This is also GREAT at night! I have wonderful stars every night, including patterns of stars like the Southern Cross which are not even visible from the US! I have the Moon go over occasionally, and even have it do a Lunar Eclipse! Even better, I can hit a few computer keys and see a telescope view of the Moon or of Saturn or of the Pleiades or the Andromeda Galaxy or about anything else. I suppose I could even have Superman pass overhead! (Or Santa in his sleigh!)
My BRAIN knows that it is not actually a skylight, but the rest of me seems to fully accept it! Maybe when flat-screen TVs get even cheaper, this idea may become more practical!
Bodyfat, Weight Loss, the Physics of Body Weight Control
Accurate and Easy Bodyfat Determination
Determining Your Accurate Bodyfat Percentage (Automatic Calculator)
A Physicist's Weight Loss System A Sleeping Weight Loss System!
Shouldn't self-sufficiency also relate to controlling bodyfat???
C Johnson, Theoretical Physicist, Physics Degree from Univ of Chicago