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    OOps, perhaps I should have posted that on the stirling design thread, and not the LTD thread. so sorry.
    John



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    Quote Originally Posted by bower
    I hope I don't step on any toes here. I've been reading the posts here, and doing my own stirling research, Re: stirling engines and power generation.
    I am looking at a project to use as "proof of concept", to re-use one, or some of the thousands of "C" Band satellite dishes littering our landscape as a framework for a stirling generator project. Thinking along the lines of designing a solar/stirling generator to mount directly in the dish framework and then make use of the power to either charge batteries or to sell the power back to the grid......
    Just like Mac Donalds, duplication as a business model. I'd like nothing more than to have to get up early in the am, and see to several generators, and then cash the check from the utility co. to supplement my retirement.
    John
    That is also the track that I intend to pursue, with the exception of selling power back to an electrical utility. Attempting to sell power back to a utility company with the required auto connects/disconnects/ WH meters/Phasing equipment, and so forth will require more investment than one can ever recoup in one's lifetime. Utility companies are not in business of buying back energy from their customers.

    Jerry



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    Bower - I like your idea of re-using a redundant satellite dish. Neat.
    I'm not sure what the availability of old dishes is on this side of the pond, but it seems like a much better use of the metal than the original.
    Oops, nearly got on my hobbyhorse there.
    John

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    Quote Originally Posted by bower
    I hope I don't step on any toes here. I've been reading the posts here, and doing my own stirling research, Re: stirling engines and power generation.
    I am looking at a project to use as "proof of concept", to re-use one, or some of the thousands of "C" Band satellite dishes littering our landscape as a framework for a stirling generator project. Thinking along the lines of designing a solar/stirling generator to mount directly in the dish framework and then make use of the power to either charge batteries or to sell the power back to the grid......
    Just like Mac Donalds, duplication as a business model. I'd like nothing more than to have to get up early in the am, and see to several generators, and then cash the check from the utility co. to supplement my retirement.
    John
    John,
    Feel free to edit add to my Sterling Engine wiki (http://www.pminmo.com/wiki/index.php...irling_Engines) as I too want a proof of concept generator. As to selling energy back to the utility, and individual that has room and is willing to do the investment can probably supplement their income. But it will take a fair amount of generation capability, which means many machines not just one.

    Distributed power generation is how most grids are now, but just huge power generators. A project that create plans that the serious homebrew types can complete successfully is my goal. i.e. "build it an they will come" Maybe in a decade there could be megawatts of home built power genrators, two decades hundreds of thousands of megawatts.

    Same for electric vehicles, people generating their own electricity could fuel their own electric vehicle.

    As long as old man Sun stays running, everybody could become energy independent. Hmmm, what politician will come up with a Sun tax?

    I've created a Try Wiki article on my wiki, feel free to play/edit with it.
    (http://www.pminmo.com/wiki/index.php?title=Try_Wiki) some quick instructions are on that page, create your own article if you like or a garbage article to learn/try. Keep it clean and to the subject.

    Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
    Vist my websites - http://pminmo.com & http://millpcbs.com


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    Phil - this is a drum I've been banging for over thirty years, that every village should have it's own power source.
    Then, methane digesters were flavour of the month (ugh!), but that changed to solar water heating, then wind power,and so on.
    Over here, our government is now talking of restarting the nuclear option, but also subsidising alternatives as a sop to the green lobby. Is the world full of politicians who say they listen, but chose to ignore ?
    Oh dear, another hobbyhorse exposed.
    The sun's over the yardarm, so time for a little something.
    Cheers
    John

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    Yup,
    Don't get me wrong, governments are necessary. (probably also politicians, but I reallly have to stretch with them)

    The real problem is people continually looking to their government for the magic bullet, the fix, the solution. And in some aspects government does need to be "out there". For example space exploration over the last 40 years. But now even that is starting to become less of a government project.

    --> if you haven't seen the movie "Field of dreams" this may not make sense<--
    The web is the field ("build it they will come"), for me I see my one little website as one "point of light" of information ("my baseball diamond in the corn field"). The people that participate in building machines, doing the experiments, posting their successes and failures ("old baseball players playing the game") are the key players.

    My goal for my homelife is to generate my own electricity, convert a vehicle to plug and play electric (plus onboard small onboard IC engine and generator to assist in extending range) and making my home or building one highly efficient, and minimize the "compromize" of current on grid energy consuption and vehicle comfort and safety.
    I'm doing this out of practicality, not because I've had this "Green awakening", and because it is just common sense, the technology isn't a big issue these days.

    Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
    Vist my websites - http://pminmo.com & http://millpcbs.com


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    Have'nt seen the film, Phil, but the image is very clear. the direction, too.
    Parallel lives possibly, leading to parallel aspirations.
    the only formal training has been as a technician, but the life experience has been as a craftsman/artisan. Now age, and retirement from that particular world, has directed us(me and SWMBO) towards finding out what is important for us, and it is through the technology formulated on forums like this one that has enabled us to drive our dreams forward.
    Regards
    John

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    Thanks for all the positive comments.

    I live in Eastern Oklahoma, next to a very large lake, (Man Made, to supply flood control and Make-up h2o for the Arkansas river navigation system, Lake Eufaula has 629 miles of shoreline). We were fortunate enough several years ago to put a law on the books requiring our public utilities to buy back power, truthfully, I haven't yet examined the actual costs involved to do it.

    I had in mind several generators ballparking that the 10' dia. dishes have around 2 sq. meters of area with a 20 percent conversion, that's still 400W per dish, per min, per hour, per day..........

    It might be better in the long run to go with a bank of solar collectors charging a "heat Battery" and running a much larger med. temp diff, stirling motor on this heat with a much larger generator. I am not an engineer, and I don't play one on TV.

    I do however like to tinker.......



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    Default World Energy Conference - Brazil

    I found this site which covers many aspects of solar, bio-fuels, wind power, water/wave power and so forth. It says that a solar powered stirling engine system is the most effective method of producing electricity. It is a large site and gives lots of data about the efficiency of different systems. It is based on the World Energy conference.

    http://www.inforse.org/europe/dieret/dieret.html

    Jerry

    Last edited by CJL5585; 07-19-2006 at 07:03 AM. Reason: To add information.


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    Has anyone ordered any parts, begun any work on any project yet?

    Seems the thread has just ceased to exist.

    I have purchased some parts off e-bay, but have yet to receive most of them. Also, have to buy some additional equipment for my lathe to machine a Solar Stirling engine for my Proof of concept project to generate electricity.

    Jerry



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    Hi Jerry.
    Yes, I've got 20metres of aluminized melinex(space blanket) 76cms wide(or 22yds x 30" for your side of the pond) as a start towards a solar sterling.
    I plan to make a single dish 30" diam first, as I've got a motorised telescope mount already set up in the garden doing nothing(another project in waiting). This will enable me to get the mount sorted first, then I can bolt on each attempt at a sterling and run tests on each design mod as it evolves.
    Currently, I've spent several evenings trying to come up with a simple constructional method for producing a circular air-tight drum. Several ideas in competition, but not settled on one yet.
    The current heat wave here is slowing down the brain cells.
    John

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    I'm not sure if it will come into the definition of this thread as I don't know quite what "low temp differential" might cover, but for the time being, until asked to start another thread here is the first project drawing of the mirror sections I'm considering.
    They're all based on the idea of using a thin membrane pulled down under lowered pressure to form a spherical mirror.
    The sterling will be used to generate electricity as a first goal, but it may well get diverted into other uses.
    John

    Attached Thumbnails Attached Thumbnails Low Temperature Differential Stirling-mirror_section-jpg  
    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    John,
    Good to hear from you. I had a bid in on a glass parabolic dish 30 inches in diameter, but some guy oubid me by $1.00 US in the last 10 seconds. So, I am have to either convert or build some kind of dish.

    I have a bid in on some mylar covered cloth. The cloth looks like aluminum foil except it is very flexible. It has a mirror finish. I thought about stretching one of these pieces over a round frame..... and since I have some expertise working with the rubber backed mylar, I surely hope to have some sort of success in creating a dish.

    I am working on the design of a single piston Sterling engine. I am hoping to have a self-starting unit without any flywheel. A HUGE challenge. The next challenge will be to build a prototype with a horizontial stroke for use with a linear electrical generator.

    Got plenty of work cut out for me to accomplish this and work past the dead ends.

    Jerry



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    Quote Originally Posted by greybeard
    I'm not sure if it will come into the definition of this thread as I don't know quite what "low temp differential" might cover, but for the time being, until asked to start another thread here is the first project drawing of the mirror sections I'm considering.
    They're all based on the idea of using a thin membrane pulled down under lowered pressure to form a spherical mirror.
    The sterling will be used to generate electricity as a first goal, but it may well get diverted into other uses.
    John
    I like your idea. I was considering a round frame with the mylar stretched like a trampoline with some sort of disk fastened to the center so I could change the parabolic curve (or focus) by pulling the center section toward the rear of the unit where I would have a mounting frame. Sounds simple enough in idea form. However, that would be a lot of bungee cord.

    Jerry



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    John,
    Just had another brainstorm. The other day I saw some NEW hula hoops for sale at a discount store. 2 or 3 spliced togather with wooden dowel pins MIGHT give me something to test a concept with. At least the outside circle.

    Jerry



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    Ok it's confession time.
    My first idea was to take a bicycle inner tube, inflate it, then use double sided sellotape to stick the mylar film to both sides. The problem of then reducing the pressure inside the "drum" led me to replacing the second film with a rigid layer, say plywood.
    Then I thought that the whole thing would be too flexible, and that some sort of conical back would solve that.
    Part of my past craft work has been to make frames to display fans in, so I've some experience of making semicircular "drums" with a single layer of 1.6mm ply bent round an MDF hoop. They are remarkably strong for their flimsy construction, but currently I don't have and ply in stock. Another idea was something I've seen wood turners do to make bowls from a flat layer of wood. Cutting a continuous spiral into a disc of 10mm MDF, then pushing it down in the centre would give a very strong cone/dish.
    It would have to be made air-tight with plenty of paint.
    I want to try to keep reproducibility in mind when I do make the final decision on which method.
    Perhaps we need vacpress on board to give us a simple method to vac form the dishes ?
    John

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    Sounds like a new thread I would like Vacpress to start.

    "How to create a Vacumn Press formed parabolic dish for solar experiements."

    Think he could be conned? I tried to send him a PM but his mailbox is full and it would not accept any more messages.

    Jerry



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    Default Almost parabolic dish

    Make an open ring out of wood or metal. Support it horizontally and attach your film to the ring. Push the film down and fill it with water; the weight of the water will cause the film to form a catenary curve which is probably close enough to what you need. Now the more awkward part; fiberglas the bottom side of the film so it retains the shape when you empty out the water.



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    With the number of projects he's got on, I'm not suprised at the full mailbox !

    Just made my first mirror in 2minutes - plastic wastepaper bin/double sided tape/mylar.
    It's flat cos I couldn't wait to try the tape as an adhesive. No problems there except you've got to get it right first time - it wont let go !
    John

    Attached Thumbnails Attached Thumbnails Low Temperature Differential Stirling-first-mirror-jpg  
    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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    Hi Geoff.
    Yes, I think fibreglass is the way to go for the production method.
    I'd pondered simillar thoughts along the lines of concrete/plaster of paris - whatever was available really. But my final idea was vacuum forming, with an equally simple set up. It does have the elegance of only requiring a single sheet of material, but I think I'd still use the mylar film for the mirror, a slightly deeper curve for the vac form, and a low pressure gap. Mylar film is cheap, and so is acrylic plastic of a suitable thickness, but I would guess that aluminised acrylic might be a silly price ?

    It's like doing jigsaw puzzles in the dark.
    Enjoy today's problems, for tomorrow's may be worse.


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