Media Workers and TV Researchers - Please seek permission before posting on this site or approaching individuals found here by phone or email - write to the Editor - mail to nick@off-grid.net


Forum Replies Created

Viewing 15 posts - 526 through 540 (of 547 total)
  • Author
    Posts
  • in reply to: DIY Solar Power Systems – ripoff #64449
    elnav
    Member

    mcts 70-640. (weird name; what are you a MS engimeneer? < grin>

    I do not know if you work for FreesunPower or is just an enthusiastic supporter but I just reviewed their website. Several things ticked me off. The Calculations page requires Java script; something I cannot access with my Linux machine. So that part of the website is totally useless to me. Then I got into the section about batteries. What a load of drivel. Instead of having some journalism student who evidently writes a lot about the performing arts they should have a technical expert write the descriptions and then have some journalism student fix grammar, syntax, and spelling. The article was technically flawed and expressed an opinion not supported by facts. If I could rate that particular article I would give it an ‘F’ for failing to be technically correct.

    in reply to: India Game Developer Summit Announces Program and Speakers #64446
    elnav
    Member

    I’m curious. How does this relate to off-grid living

    in reply to: free magnet energy #64445
    elnav
    Member

    This has all the appearances of a bald faced pitch for money. Over the years countless proposals for over unity generators have been made including some with detailed technical descriptions and assembly drawings. Not one of them have withstood the test of someone actually trying to replicate the device. Engineering forums with peer review of the developments have debunked all such attempts of producing a workable ‘free energy generator’ Convince me you have circumvented the immutable laws of physics.

    I’m not convinced by a picture of some rotating pulley and a sound track of what sounds like a sewing machine. We did not see any real work performed by connecting the output to an actual load nor were there are output meters showing actual current and voltage leaving the round ‘thingie’ and doing real work. Being Australian; could it produce 120V 60 hz instead of 230V 50hz? If so how would it do so?

    in reply to: Power Systems beyond generator… #64442
    elnav
    Member

    Dingo3X wrote: “i’m looking more for a basic tutorial,i’m more a do-it-yourselfer… i’m looking more towards information about what kind of components go into the electrical system and the ways the sub-systems interact.

    Comment.

    The above question is probably what many DIYer asks themselves. The answer depends on so many variables its hard to define in an article of 1500 words or less. Broadly speaking hydraulic generated power falls into two catagories. AC voltage usually at a level close to mains voltage or DC voltage close to battery voltage levels. Either way the power must be conditioned before use. There are any number of controllers available to handle the task. Low voltage alternators may include a fixed voltage regulator inside the casing as for example in an vehicle. AC voltage has to be regulated to something that can be used without harm to the load being connected. This can be accomplished electronically and is not recommended for DIY construction except by experienced electronics circuit builders. Close regulation is essential to avoid destruction of the loads connected to this self generated power. For example continually low voltage will cause inductive motors for fans and pumps to burn out. Excessively high voltage will cause insulation to break down and cause a fire.

    If the generator output is DC it must be closely controlled to prevent boiling dry the battery or if too low, it is not going to deliver a charge to the storage battery.

    When storing power a third requirement comes into play. What happens when the continuously running generator delivers excess capacity? Either the generator has to stop or the output is diverted elsewhere. The wind and solar industry has provided solutions for many years, so even a cursory perusal of their product offerings should give the newcomer a good idea of how to deal with that problem.

    Unless the installation is located in winter climates one possible solution is to pump up water into an elevated tank for later use in washing, irrigation or even run through a small water turbine for additional power generation. This concept is called pumped storage and is used extensively in places like the Niagara Falls area as well as in other parts of the world. It is even possible to use this technique for seasonal storage but this involves structures far beyond the capabilites of the average off grid individual.

    From the above it should be obvious that a reliable and sometimes complex regulator or controller is required as a first stage beyond the raw generator powered by the waterwheel.

    Beyond the regulator box power, distribution takes on a familiar look. For AC the typical home panel with breakers or fuses mounted in a metal enclosure will suffice. For DC a fuse panel or circuit breaker box like those sold for RV vans or boats will do nicely.

    It may come as a surprise to newcomers to learn low voltage DC wiring often requires larger diameter wires than AC wiring. This is necessary to avoid excessive line losses.

    However that should be the subject of an entirely new thread.

    in reply to: Solar A/C #64443
    elnav
    Member

    Excellent link 12Vman. Many of the current generation who are looking to go off-grid are too young to remember the first oil crisis we had in the seventies. Back then a number of architectual proposals emerged to take advantage of this earth tempering effect. It ranged from burying houses under several feet of earth to actually digging down underground. The absence of windows was one of the biggest obstacles to widespread acceptance of the concept.

    Today’s ‘geothermal’ systems are an outgrowth of this early thinking. Instead of using air to transfer the heat, liquids such as water or ethylene glycol is used to effect the transfer.

    The downside being the need for a sizable plot of land from which to extract the heat in winter or collect the cold (technical purists please forgive the inaccuracies in that last statement)

    Some geothermal systems use vertical pipes to get around the land area restrictions. Somehow I doubt it would be as successful with an air pipe system.

    Some places have land that does not lend itself as well to this cooling method. Cost of digging or trenching in near solid rock makes it cost prohibitive.

    in reply to: Power Systems beyond generator… #64436
    elnav
    Member

    I realized you are a DIYer but the questions I asked are so basic that if you do not know the answer then you should not be attempting the project. If you do not know the voltage or current coming out of the generator how will you know what to do with it? If it’s AC you can’t just connect a battery or you will damage it and even if it is DC but too high a voltage then you will still damage the battery. If it is too low nothing will happen and you will become frustrated wondering what didn’t work.

    A complete tutorial will run to many pages far exceeding the capacity of this forum text box. There are so many possible tutorials already available on the internet its hard to guide you without knowing what your present level of expertise is. Since you managed to build a generator I assumed you already had some of the fundamentals. The question becomes where do you want to go with the knowledge you already have. Distribution is simply a question of breakers or fuses, some bus bars and switches. As for whether or not you can maybe charge a back up battery. That all depends on what the answers are to my questions. Do you know what voltage and current is coming from the generator. Is it DC or AC?

    in reply to: Power Systems beyond generator… #64437
    elnav
    Member

    … i’m looking more towards information about what kind of components go into the electrical system and the ways the sub-systems interact.

    REPLY

    In a nut shell you need over current protection in case of a short circuit. You may need protection against electric shock hazards that could kill you if the voltage is high enough.

    If you plan to run multiple devices you need to know something about load management unless this generator is far bigger than I think it is. If it is really big you need protection against electrical fires etc.

    As for components you need meters, breakers, bus bars, switches and enclosures. Not knowing what part of the world you are in its hard to tell you what supplier is best bet for getting the right parts.

    in reply to: Power Systems beyond generator… #64434
    elnav
    Member

    Dingo3x

    what do you want to know?

    I design such systems for a living.

    How much power are you generating?

    What voltage and current is your system.

    How do you plan to store the power you generate?

    This forum has limited capacity for extensive replies but I can provide some quickie answers right here.

    in reply to: Canadian well construction. #64429
    elnav
    Member

    Bobcabin, could you please explain in better detail what exactly you mean by “canadian well” I live in Canada and have not heard this terminology used. Are you talking about a drinking water well? In most areas of Canada well water pipes enter the building below the frost line to prevent the water from freezing in winter. Hence your description about condensation on the exterior of the pipes makes little sense. If outside air can reach the pipes so can freezing temps and then the water inside the pipe would freeze in winter.

    in reply to: Solar A/C #64431
    elnav
    Member

    Because the original post talked about running central air from an electric power source I totally forgot a discussion I had with a colleague a couple of years ago.

    I had come across a reference to central air conditioning in the pre-electrified Arabian peninsular. during the discussion my friend said he had visited such a home while working in the United Emirates. well that got my attention. Seems the Arabs of the nor tenth century had developed a form of central air in the same way Romans had developed central heating before the time of Christ.

    As hard working hippie has already mentioned insulation is the key.The Arabs used crushed coral or blocks cut from coral to build walls a couple of feet thick. The design of the building is also key. A central atrium is surrounded on four sides by rooms having few windows and none facing out on the exterior side.

    A corridor goes around the building returning to a corner on the soutnern wall. At one or both corners a square tower at least 30 feet high is erected and the interior is divided by diagonal walls forming triangular vertical air shafts. The tower walls are thin so sunlight heats the south facing wall. The northern wall being in shade is somewhat cooler than the opposite side. The air shaft on the southern side is connected to one end of the corridor circling the building interior and the northern air shaft connects to the opposite end. A wall prevents direct connection of the two ends of the corridor. Solar heating forms a thermal chimney effect in the south side air shaft and hot air rises. Meanwhile the cooler north air shaft permits cooler (relatively speaking) air to drop and enter the corridor as make up air replacing the hot air being exhautsed. As a further cooling effect long strips of fine mesh muslin cloth hangs in the north air shaft and is constantly wetted by water being dripped on the cloths. As the water wicks down along the cloths evaporation causes additional cooling and the air entering the corridor is about 15 degrees celcius cooler than the ambient air.

    considering the owner of the building was an engineers and my fried also ghad considerable technical training I am inclined to believe the description and how it worked. The building in question had been in the engineer’s family for generations and he found no reason to change a non electrical solar powered system when it obviously was working. About the only modernization was replacement of the slaves that used to carry jugs of water to the top of the tower. Now a water pump piped water to the top an

    d sprinkled water on the cloths used as evaporation screens.

    While visiting the south I have experienced evaporation type air conditioning and can attest to how refreshing and cooling it can be. Especially in the desert. in parts of the southern US they are coloqually refered to as swamp coolers. This may give you an ide of how to cool a house with little or no electrical input.

    in reply to: Living off-grid is not hard! #64432
    elnav
    Member

    Lamar how well does your solar composting toilet work during the winter when covered by snow and the outdoor temps is freezing for four months of the year? would it be possible to provide heat from a wood fire?

    What suggestions do you have for a young couple with a growing family regarding lifestyle. 400 square feet could be a bit crowded with youngsters underfoot and possibly confined indoors during inclement weather. You are evidently blessed with a well spring that bubbles to the surface. What would you suggest as the best way to pump water to the surface given your setup. Youngsters below grade school age tend to generate a lot of laundry. How much water do you presently use and how much flow rate can it sustain as a maximum rate.

    in reply to: Solar A/C #64428
    elnav
    Member

    Insulation only goes so far and does nothing to alleviate high humidity. In some coastal climates the air conditioning is as much to dehumidify as it is to cool. I have now lived in both coastal and mountain climates. House air conditioning also called HVAC uses a heat pump that is reversible. Something not often given consideration is the age of the house resident. Especially by younger people looking at energy conserving houses. My clientele tend to be the empty nesters who are approaching(early) retirement age. Guess what? It is almost always the wife who demands air conditioning. Strange I thought. After some thinking about it I realized there was a rational explanation. All of these wives were approaching that age when they suffered from ‘hot flashes’

    The flash of enlightenment happened when my wife complained about not being able to open a window when it was a snow storm outside with -5 C temps. She complained about being hot and I was freezing in the +10C temperatures indoors. I checked it out with a few friends in the same age group. Sure enough the pattern held true.

    To someone in the twenty something to forty something age group it may seem asking for air conditioning but to someone experiencing hot flashes it is a matter of crucial importance.

    in reply to: Integrative Solar Hot Water Heater #64427
    elnav
    Member

    A picture and price would have been nice. This post sounds so much like a sales blurb you might as well give complete information. Very promising but hardly informative regarding the factual details.

    for instance what is the maximum possible flow rate. Will it provide enough hot water for two people to shower consecutively. Once the hot water has been used what is the recovery rate.

    Do I have to mount it on the roof or can I place it nearer ground level to facilitate snow removal and if so, how do I get the hot water up to second story or up higher than the solar collector. The stipulation of no pumps suggest it is gravity driven but the open non pressurized system suggest it is not a simple thermo-syphon either.

    in reply to: Solar A/C #64424
    elnav
    Member

    Salvor, it is technically possible to run air conditioning with an inverter but you probably do not want to incur the expense for the batteries needed. Most of my clients require some A/C because they are in southern climates. but they also spend several thousand dollars on a big battery bank.

    There are two ways to get 220V for an air conditioner. European market inverters normally come as 230V and at least one brand ( Victron also sold in the US ) can be switch selected for either 50Hz or 60 Hz operation. The second way is to use a step up transformer to boost 120V up to 220V. for one recent job we found a 4 kVA rated transformer that only cost USD $109 plus shipping.

    Most of the existing home air conditioners tend to be hard starting. For off grid use I recommend adding a soft start module that eliminates the huge start surge. Submerged well pump owners have been using this technique for several years already.

    For power conservation I suggest you consider using a small RV unit just to cool off the room you intend to use the most be it living room or bedroom.

    Central air conditioning units are often five or ten ton capacity and would require far too much power. Note! one ton = 12,000 BTU

    in reply to: NiMH batteries for power grid #64421
    elnav
    Member

    What kind of amp hour storage do these batteries have?

Viewing 15 posts - 526 through 540 (of 547 total)