MOST of the needs of human survival and of some level of happiness can be provided by these 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. 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, 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 amount of food, at extremely high quality, is in the realm (using the HG 3a).
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 many 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 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!). 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 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 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!
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 the Electric Company subtracts off several expenses, and you are not likely to even receive 10 cents per kWh for each of those 12 kWh that you could sell them. That's a buck twenty you could make on that sunny day. Would that really merit the giant smug smile of "independence"?
You might note that at a MAXIMUM of selling $1.20 of electricity on really sunny days, you might realistically be able to sell a MAXIMUM of around $200 of electricity in a year. So then how many years will it take before that guy in Maine amortizes $100,000 worth of solar panels on his roof? Ans: Around 500 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!
If you have explored the energy-related pages in this Domain, you probably have noticed that most take a "blue-collar" approach to most things, of discussing LOW-COST approaches to such subjects. Also, low-tech approaches to solving such needs. This is the case here, where a VERY practical electrical supply approach is presented, which actually allows you to live a pretty normal life! The people who are now off-the-grid have to constantly be aware of whether it is sunny or not, regarding whether they can turn on a light bulb! They tend to have an ACTUAL available electricity supply of maybe 250 watts to 400 watts (IF they spent a lot for the equipment!) So they could NEVER consider using a vacuum cleaner or a toaster or a hair-dryer that uses 1500 watts or so! I propose a "better approach" here, and it is also generally FAR less expensive!
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.
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 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!)
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 10 cents per kilowatt-hour, this suggests that your daily usage might be around 15 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!
(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 12 kWh to 15 kWh of electricity means that we used up about 16 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 * r * V3
* (area exposed to the wind).
Note that this is a simple application of the kinetic energy definition. r is the air density or 0.00237 lbf * sec2/ft4.
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 to try to charge each of the batteries.
(A momentary aside here! You have heard friends brag about their "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 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 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 have 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.
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, that amount of electricity can and will 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 1.8 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 $190,000 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: http://mb-soft/public/wind7.html
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 it 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, 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 the owners tend to stop using it after one winter of enthusiastic use!) Again, the only exception to this that we are aware of is the (NON-airtight) JUCA B-3B/B-3A woodstove, which, since 1973 has an overall seasonal efficiency of around 81%, and which is actually a central furnace which happens to burn wood. However, the JUCA units have 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! 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. (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:
http://mb-soft/public3/globalzk.html
The second contains all the instructions to build one!:
http://mb-soft/public3/globalzl.html
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!
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.)
http://mb-soft/solar/index.html
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.
http://mb-soft/solar/solar2.html
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.
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.) 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° 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 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.
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 was invented and Engineered in 2007). (It has been amazing that
UNICEF and OXFAM and the other giant NGOs have had absolutely no
interest in this and some 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?)
http://mb-soft/solar/saving.html
A rather different system can be used in extremely hot climates, where the Free A/C does not perform very well because the ground is not cool enough. It still involves underground tubes, but also some added components that enhance the effects. It will be discussed and presented just below, as it is actually a variant of the Refrigeration and Freezer system. This modified A/C system was invented in 2008.
Several different methods of installing this follow. They are all actually the same concept. For people in America and Europe, keep reading, and after you understand the concept, a fairly simple and easy way of providing food refrigeration and food freezing will then be described, all developed in 2008.
First, the general description of the greatest capacity system. There is an underground tube system, essentially a smaller and simpler version of the Free A/C, but where the air ONLY comes into it from the house air. In other words, this is a RECIRCULATING system, very much like all home heating/cooling systems in the United States. As that air passes through the underground tubes, it gets cooled to near the ground temperature. For discussion sake here, we will say that is for a climate probably too warm for the Free A/C, where the ground temperature is around 65ºF [like for Alabama] (which is also described by around 525ºR, a temperature system based on absolute zero).
You have dug a pit a few feet deep where you have the car engine sitting, completely below the surface of the ground! A lot of it gets removed, and only the main engine components are needed here, as we essentially use it as a simple air pump or air compressor. It does NOT ever operate as it originally did as an engine! It is actually incredibly convenient for us! The way an engine normally works is that it SUCKS IN air through the intake manifold as the pistons move down in their cylinders and then the air is COMPRESSED and then PUSHED OUT into the exhaust pipe when the pistons move upward. The engine already has valves that open and close to cause this to happen. We are simply going to use this Air Pump aspect of an automotive engine without any of the other parts of how it works! Unfortunately, because of the way auto manufacturers make the engines, they always include camshafts which do not really excel at trying to build up high pressures, but these concepts do not need high pressures anyway (unless you intend to be making dry ice [frozen carbon dioxide] at around -109ºF!)
(Also unfortunate is that automotive engines are nearly all 4-cycle Otto design engines, which causes our usage to waste some effort in compressing and then releasing the pressure during two of the strokes that we do not need. In the vehicle, those were called the Compression and Power strokes. All we are interested in are the other two strokes, Intake and Exhaust!)
You will then simply dig at least one trench to bury maybe 100 feet of the 4" PVC 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 air. So step one is to COOL the (house) 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 into what is called the intake manifold of the engine. The Savonius windmill, spinning above the engine at around two times per second, turns the crankshaft of the engine (which then spins at around 120 rpm, far slower than when used as a car or truck engine).
This then creates (generally slightly) compressed air, which you collect from the outlet of the exhaust headers. 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 engine/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 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 compression. Since most car engines have a compression ratio of around 8:1, the maximum they can create is a cylinder compression pressure of around 105 PSIG to 120 PSIG.
IF you could actually collect the air at this pressure (which is quite hard to do due to the camshaft issues mentioned above) the formulas show that the air should wind up HOT at 940ºR or 480ºF. How can this be a good thing??? Well, say you then ran that hot compressed air though a SECOND underground PVC pipe system (another hundred feet of PVC is good), where it was again cooled down to near the ground temperature of our 65ºF. (All that heat would be transferred into the soil, and then conducted away through the soil.) Now you have some compressed air inside the PVC tube at our new 65ºF. This is step three of the process, cooling the compressed air back down with the deep soil.
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! Again, if we assume the extreme limiting case of our compressed air being at around 105 PSIG pressure, when we now use the formula, we find that the released air winds up at around 293ºR. That is around -165ºF, impressively cold! Only a very small quantity of that high a pressure air could be generated, but it could actually be used to produce very small quantities of dry ice at -109ºF!
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 this type of air-based refrigeration. During the phase just after the compression, the refrigerant CHANGES STATE from being a 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 EITHER a medium-tech (using the old car engine) OR a low-tech (using a bellows or 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).
But in a hotter climate, as in an African jungle where the ground temperature is near 100ºF, this would result in air at around 35ºF, 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.
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 have been discussing using an abandoned car engine, mostly because it should be available nearly anywhere and probably for free. But since our use of it is for a VERY MINIMAL compressing of air (and nothing else) there are many alternate ways of doing this moderate air compression:
If the needs are just for Refrigeration or Food Freezing, a much smaller piston pump could be made, using any available piece of 4" pipe, iron, PVC or otherwise, for sufficient airflow. Something greatly resembling a hand-level water pump can be used.
Regarding the larger diameter approach, one end of the pipe would be blocked off and (two) flapper valves mounted there, so that the motion of the large piston would draw air in on INTAKE strokes and blow it out on EXHAUST strokes. If you make rings or seals that are REALLY good enough, this setup can produce as much pressure as the car engine would. But that is not actually the intention here, but only creating enough pressure for our modest needs. Note that since there is never any fire inside the cylinder, standard PVC plastic pipe or a concrete culvert is fine for the cylinder!
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.
Both of these Third World variants can also have the bellows or cylinder pump above ground, where it might be easier to connect to a Savonius rotor to cause the pumping action. However, EITHER of them MUST still use the underground tube to take the compressed air away! That underground tube can go toward a house, where it would then only come up right near the (hopefully insulated) box that will become the food refrigerator or freezer. That end of the (PVC) pipe will have a reducer coupling or bushing to get down to 1" diameter (PVC) pipe that will actually go INTO the insulated box. A VALVE on that smaller pipe will control how much of the pressurized air is released, which therefore determines the (naturally refrigerated) TEMPERATURE of the air that comes out! That is not quite the automatically controlled temperature inside an expensive refrigerator, but with some attention and possibly a thermometer inside the box, safe food preservation can be accomplished very easily! But if you are a creative sort, you could certainly place an electric thermostat INSIDE the refrigerator box, and another INSIDE the freezer box, where that on-off switch would release some cooling, expanding air whenever the chamber had gotten warmer than what you set the thermostat at! So you CAN get the same automatic operation that we are used to in America and Europe!
The tank does NOT need to be under the house, or even very near it! The available coolness is as compressed air at approximately the deep soil temperature, so a small (PVC) pipe could carry some (a small amount) of that air a considerable distance to where an insulated box could be used as a refrigerator or a food freezer.
Three of the pipe connections are used, with any other pipe fittings removed and replaced by threaded pipe plugs, with suitable thread sealer. The tank should be placed in a position where one of the pipes will be connected at the lowest point, which will be a drain for any accumulated water. Since the tank is always pressurized, if a pipe valve is simply opened on this line, any accumulated water which has condensed would be expelled out. The other two pipes need to be the largest diameter connections (and pipes) as possible, as they will actually be used for AIR flow and not water flow.
The first of these two goes upward, to ANY air pump or air compressor, even a bellows. That is the SOURCE for the compressed air in the tank. The second is the pipe which carries some of that compressed air to the insulated box which is to be used as the refrigerator or freezer. That pipe could be split into two branch pipes. Each would have a solenoid valve controlling air flow through it. The one to the refrigerator box would have that solenoid valve controlled by a thermostat switch INSIDE the refrigerator box. If the box thermostat rose ABOVE 38ºF, then the solenoid valve would open, releasing some of the compressed air into that box, where it would expand and greatly cool down (as discussed in this entire presentation). If that box thermostat dropped to below 34ºF, it would shut off and disconnect electricity from that solenoid, thereby stopping any further cooling of that chamber. The refrigerator would therefore always stay in the range of 34ºF to 38ºF temperature. A second branch pipe, with its own thermostat switch inside a freezer chamber, would do the same, but with the thermostat set at 15ºF and 25ºF, ensuring that everything inside that freezer chamber would always remain frozen.
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 527ºR temperature (the absolute temperature that is the same as 68ºF.)
579ºR/459ºR
so the fraction is
1.2614
Because of the exponent, the ratio of the pressures is therefore
2.245
Since the ambient air pressure is 15 PSIA, this means that the bellows or cylinder would need to produce around 19 PSIG. This can be hard to achieve, especially with bellows. So for full food freezing when the air temperature is 120ºF, the underground intake tunnel may be necessary. In that case if the 120ºF air is cooled to the 80ºF deep soil temperature before it gets compressed, and we would have a different calculation, where the fraction would be:
539ºR/459ºR
so the fraction is
1.1743
Because of the exponent, the ratio of the pressures is therefore
1.75
This results in needing only 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!
559ºR/489ºR
so the fraction is
1.1431
Because of the exponent, the ratio of the pressures is therefore
1.59
This results in only needing 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 100ºF air is cooled to 70ºF before it gets compressed, we would have a different calculation, where the fraction would be
529ºR/489ºR
so the left fraction is
1.0818
Because of the exponent, the ratio of the pressures is therefore
1.31
This results in needing only 4.5 PSIG where 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. 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 they 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.
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 52ºF or so. The other set of tubes would be just a few inches below a specific surface area. IN WINTER, the 52ºF 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 52ºF 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 (52ºF) that it might initially not seem useful at all!
Similarly, there are a lot of possible uses of the 150ºF 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 deept to capture the coolness of 52ºF deep soil (or sand) and the other set just six inches deep, to run that cool air through the extremely hot (120ºF) 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!
So try to avoid those 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!
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C Johnson, Physicist, Physics Degree from Univ of Chicago