Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?

Off Grid Via Slow Moving River? 452

einstein writes "I live out in the middle of nowhere, and I lose power at the drop of a hat. My house is right next to the Susquehanna river, and all the kinetic energy going past my house makes just want to go off grid. Most homebuilt hydro power is lower volume/high speed. What would be a good, unobtrusive way to generate electricity from a high volume/low speed body of water? I'm between two large hydro dams, so the water level is fairly constant, but does tend to fluctuate 4-6ft in the winter due to ice floes and melting snow. I think maybe a miniature version of one of the recent submerged tidal generators might work... Does anyone have some suggestions on how I might go about this project?" More than a few people have done this before.
This discussion has been archived. No new comments can be posted.

Off Grid Via Slow Moving River?

Comments Filter:
  • The Romans (Score:4, Interesting)

    by panxerox ( 575545 ) * on Sunday April 11, 2004 @03:23PM (#8831881)
    did something similar, they had a line of floating grain mills across the Tiber (no ice there though) in the late empire period. Find a good high current area and build a paddlewheel boat basically with the drive attached to a generator and use anchors in the riverbed. It might not generate a steady high elec current so you might want to put in a bank of batteries and converter for peak demand. Since the paddlewheel is in the back the boat draft would break up at least thin ice. With underwater turbines your talking alot of cost both in construction and maintainance. Hers another option
    • Re:The Romans (Score:5, Insightful)

      by mikewas ( 119762 ) < minus herbivore> on Sunday April 11, 2004 @03:34PM (#8831953) Homepage
      Probably easier to build a dock, floating or fixed. A dock is something that the local officials will understand so any permits or approvals should be easy. Then attach the paddlewheels.
      • Re:The Romans (Score:3, Interesting)

        by snerdy ( 444659 )
        In Joe Sacco's excellent comic documentary "Safe Area Gorazde: The War in Eastern Bosnia 1992-1995" he talks about how the residents of Gorazde built floating water-powered generators in order to run lights and electric applicances like TVs and VCRs during the siege of their town. The generators were called something like "mini-turines?" (I borrowed the book from a friend and have since returned it.)
    • Stupid Romans (Score:5, Insightful)

      by fm6 ( 162816 ) on Sunday April 11, 2004 @04:11PM (#8832194) Homepage Journal
      The party line in all the history books I've read is that the Romans had water mill tech, but it only accounted for a tiny portion of their flour production. The Roman economy was based on plentiful slave labor, so finding way to do things with fewer people (in this case, hand-powered versus water-powered mills) was not a big priority.

      If you know of references that rebut the standard historical theory (wouldn't be the first time), please post links or titles. I'd want to read them

      Anyway, it's my understanding that water mills began serious development during the "Middle Ages". Modern Western culture is descended from the great cultural renaissance of the 15th century, and we've inherited their prejudice against the "Middle Ages", that 1000-year period after the fall of Rome where Western progress supposedly ground to a halt. But this period was when people started playing with technology seriously, and thinking about ways to use it to make life easier -- and to get rich. In short, it was the period that gave birth to the techno-geek!

      • So clearly the solution is to invade some neighboring town, taking the people as slaves to turn a giant generator for you.

        Those Romans were smart people...
      • Middle Ages (Score:3, Insightful)

        by ChrisMaple ( 607946 )
        Dark Ages: ~476 C.E. to ~ 1000 C.E.

        Middle Ages: ~500 C.E. to ~1500 C.E.

        Renaissance: mid 1300's C.E. to mid 1700's C.E.

        The Dark Ages are rightly named. The late Middle Ages is when civilization reversed its deteriorating trend.

    • In fact, I have seen people rig up homebrewed windmills fairly easily with bicycle parts to transfer the energy and to experiment with different gear ratios. Bike parts are tough, cheap, plentiful and easy to work on. It seems to me that you could build a paddlewheel boat fairly easily and link the paddlewheel to a generator with some old beater bike sprockets. Go with steel, aluminum wears to fast for constant use. Instead of lubing the chain with oil, use grease. A nickel plated chain will resist corrosi
  • by Anonymous Coward on Sunday April 11, 2004 @03:23PM (#8831882)
    If you manage to generate your own power (wind, water, solar, whatever), stay on the grid because YOU can feed the grid, and the power company (usually) has to credit you. Yes, keep some of your own power stored up in batteries, but sell the excess and pay off the costs of setting this up.
    • An energy efficient home in the uk that generates it's own power through wind (people high up on hills) can pull a tidy side income to help pay for that next holid^H^H^H overclocked uber pc.
      • A friend of mine makes over $600 a month by staying on the grid and setting up a few wind towers.
      • There are people in Australia who get money from the electricity people through their solar panels feeding back into the grid too.
    • I believe that's a federal law here in the US, and if not, it's at least a state law here in PA, but I don't know about NY (PA and NY are the two states the Susquehanna river is in).
    • by MrChuck ( 14227 ) on Sunday April 11, 2004 @03:44PM (#8832021)
      I'm in the process of Solarizing an odd grid house...

      Battery system will add a bit to the cost (but still might be worthwhile for keeping "absolutely needed" systems up (refrigerator)). But unlike solar, rivers run always. You can start without it and power your house, sending extra to the grid and making money on it.

      But note that a Rolls 375AH battery will cost you $600-$700 and you'll want a few of those. Plus charging systems for them. And replacing them every 5-8 years. (tho fuel cell systems are expected to work for this use within 3-5 years).

      HomePower Magazine [] is online and in libraries and just had something (Feb? March?) on home hydro []. It's often used with creeks. You can also buy their entire archives on CD.

      If you need pressure, but don't think your river has it, note that running water into a large pipe and getting smaller makes pressure enough to turn things.

      The easiest way to handle it is with a, er, hill. Divert some of the water off through pipes, let it drop, let it hit your generator and route it back to the river. Filters and cats at the top keep fish out.

      • storage (Score:5, Informative)

        by zogger ( 617870 ) on Sunday April 11, 2004 @04:10PM (#8832183) Homepage Journal
        I have a lot of experience maintaining a large bank of rolls/surrettes and some trojans ( and others). One, they'll last a lot longer than 5-6 years, especially is you install a desulphator on the battery bank. They *work* as advertised, I highly recommend them. I've actually rejuvenated some marginally rank batts with them. neat stuff, the gov and some industries use them a lot to, to keep starter batteries "fresh" for long unused storage conditions with vehicles that only get occassional use.

        On the batts, the rolls are definetly good, and definetly expensive, along with the crowns. I have found cost comparing, it might be useful to check out local forklift companies and get a battery bank from them. These are deep cycle "traction" batteries in steel boxes. Whoppers, and with batts, it's the lead, the size, bigger is better more or less. You can get a 12 volt bank for around 6-800$ that will hold twice (roughly) as many amp hours as the equivalent-in-money rolls batts. Plus, if you are near any big city with the foirklift dealer, you can go get the thing yourself,(heavy, be prepared for some egyptian engineering to get them in place with levers and ramps and dollies and whatnot) usually rolls batts need to be shipped in,too, kinda spensive...

        the forklift batts come 12/24/ 36 / 48 volt so you can pick your voltage requirements. Most home systems are 24 or 12 volt at the storage, depends on how far away your panels are, and how much thick expensive copper wire you want to run. You can (if you really want to) CAREFULLY cut the welded busbars on the top of the forklift batts and do your own custom series/parallel wiring as well,to get whatever voltage you want (say knocking down the 48 to a 24) but I'd recommend just sizing for your needs and purchasing appropriately.

        Good luck!
      • Filters and cats at the top keep fish out.

        But what happens when the cats over-eat, get fat and die?

        • Gorillas (Score:5, Funny)

          by AtariAmarok ( 451306 ) on Sunday April 11, 2004 @04:22PM (#8832256)
          But what happens when the cats over-eat, get fat and die?

          Then you get dogs to eat the cats. If these become a problem, you get gorillas to eat the dogs. The gorillas won't be a problem, because, come winter, they will freeze to death.

          I don't think the cats will be a problem, however. Garfield has been over-eating and very fat for 30 or so years now, and I still see his sarcastic face in the funny papers every morning.
      • by rpeterman ( 230092 ) on Sunday April 11, 2004 @05:00PM (#8832509)
        "running water into a large pipe and getting smaller makes pressure enough to turn things."
        This is incorrect. I regularly teach irrigation-related hydraulics classes to professionals in many fields, and this is one of the most common misconceptions about hydraulics. Decreasing pipe size increases velocity, not pressure. Increased velocity in pipes is usually associated with friction loss, or loss of water pressure. Water pressure is only created by the weight of water (with minimal additions from atmospheric pressure) or by mechanical means (pumps).
        Increasing the velocity may be beneficial in certain situations, but in this case I would convert the low pressure, low velocity energy from the river to electricity by using gears, pulleys and other mechanical aids. The river has plenty of mass to drive a large water wheel which would, with a high reduction ratio, turn a small shaft on a generator at the speeds needed to generate electricty.
    • by fm6 ( 162816 ) on Sunday April 11, 2004 @04:29PM (#8832288) Homepage Journal
      In theory, yes, the local power company often has to buy your surplus. In practice, though, it's often less simple [].
    • by vikingpower ( 768921 ) on Sunday April 11, 2004 @04:33PM (#8832329) Homepage Journal
      Absolutely: DO stay on the grid. For 2 obvious reasons: 1) what if, you never know, your installation breaks down beyond repair ? 2) it's profitable I am in a monastery in the Netherlands. We are going to generate our own electric power, with windmills ( we are very close to the North Sea shore, have 200+ days of wind per year ). Not only for the monastery-house itself, but also for the candle factory with which we earn our money: heating paraffine eats kilowatts. But even under these favorable circumstances we would be mad to go off the grid.
  • by no_such_user ( 196771 ) <jd-slashdot-2007 ... mal l d a y .com> on Sunday April 11, 2004 @03:26PM (#8831901)
    I'm a big fan of Home Power magazine []. They focus more on solar solutions, but you'll catch an occasional article on hydro. Best part is you can download the current issue [] for free (after registration).
  • by niko9 ( 315647 ) * on Sunday April 11, 2004 @03:27PM (#8831909)
    You woudn't happen to wear a 50's era bifocals and live in a van down by the river?
  • Township Approval (Score:5, Informative)

    by Anonymous Coward on Sunday April 11, 2004 @03:28PM (#8831910)
    What would be a good, unobtrusive way to generate electricity from a high volume/low speed body of water?

    You'll need township approval before even thinking of constructing something that could possibly damn or slow down the flow of water.
    • John Ashcroft (Score:3, Insightful)

      by EventHorizon ( 41772 )
      We need government approval to think? Damn. That's worse than 198


    • by itomato ( 91092 )
      In some places, as long as you don't completely block the flow, just about anything goes. It may be inconsiderate, but if it is, then you've got more than a few neighbors downstream to contend with when they find out it's you!

      Common sense, fairness, and respect go a long way in the country. That's why it rules so fucking much!

    • by tunabomber ( 259585 ) on Sunday April 11, 2004 @03:58PM (#8832109) Homepage
      You'll need township approval before even thinking of constructing something that could possibly damn or slow down the flow of water.

      Crap. Better rethink my plans to build a Church of Satan on the bank of the Animas River (in my backyard). The people of Durango might not be too happy that their river has been condemned to eternal damnation, especially since "animas" is Spanish for "soul".
  • by Anonymous Coward on Sunday April 11, 2004 @03:29PM (#8831924)
    I've noticed while wearing socks and walking on carpet, I often generate static electricity. Is there any way to harness this electricity to power my home, rather than shock me when I touch metal objects? In a related question, could I somehow generate power by rubbing balloons against my hair?
  • High torque (Score:5, Interesting)

    by 680x0 ( 467210 ) <vicky.steeds@com> on Sunday April 11, 2004 @03:30PM (#8831928) Journal
    I bet you could build a low-speed, high-torque paddle wheel (it would need to have a lot of surface area being pushed on by the river). Then, using gear ratios, you can convert that to high-speed, low-torque that may be needed by your generator. Not being a mechanical engineer, I'll leave it at that. :-)
    • Re:High torque (Score:5, Informative)

      by SatanicPuppy ( 611928 ) <> on Sunday April 11, 2004 @04:21PM (#8832250) Journal
      Submerged wheels are less efficient than wheels powered by falling water, which is something to look into if you live on a rough sort of incline. You could run a sluice to a smaller wheel for the same amount of power if you have a small decline on your water frontage. (Or you could dam the river, ha ha).

      A big wheel could run afoul of your winter time ice floes...A nice sized chunk of ice could wreck your system.

      A full underwater system (i.e turbines) would look better, and would probably be safe from ice. Turbines are much more expensive though.
  • Wind Power! (Score:3, Funny)

    by Anonymous Coward on Sunday April 11, 2004 @03:30PM (#8831930)
    The basic idea behind hydro power is that you take the potential energy of water falling a vertical distance, and convert it to electrical energy. You will have trouble with that in your area. The fact that the river is slow movign tells me that the gradient in the area is very gradual, so it will be difficult to rig up a system where the water is able to travel a vertical distance. Basically you would have to build a dam to block the flow of water so it rises on one side.

    I don't think tidal power would work unless the river level fluctuates daily (tidal generators produce power only during a level change).

    My suggestion: forget hydro power, and build a windmill!
    • Potential energy extraction is not the only possibility.
      You can also extract *kinetic* energy of the water in undershot water mills.
  • by polished look 2 ( 662705 ) on Sunday April 11, 2004 @03:31PM (#8831940) Journal
    ok, say this person puts in a paddle-boat or what-not which drives a generator. Does this remove energy from the river? will the downstream hydro-electric plant have less energy?
    • Without understanding hydro dynamics at all I can comfortably say that if you gain some energy from the water then yes it has either lost some kinetic energy (or some mass)
      • I'd feel comfortable assuming he's not going to convert any of the water's mass directly into energy. Still, an above poster noted that the downstream dam just stores the water in a resivor, so they won't notice the difference from this project.
    • by RallyNick ( 577728 ) on Sunday April 11, 2004 @03:43PM (#8832016)
      yes, but just momentarily. once past your paddle, the water will be accelerated again by earth's gravitational pull, so the downstream power plant won't ever notice.

      p.s. it wouldn't notice anyway since they just store the water in the dam and let it free fall on their turbine from there. so your plant will make the water take longer to reach downstream but it'll have just as much energy once there.
      • There is a difference between undershot and overshot waterwheels.

        Undershot waterwheels use primarily the kinetic energy of the water (the situation you depicted above).

        Overshot waterwheels use mainly the difference in potential energy. This is (in essence) the technology which is used in all the big dams and you can draw a lot more energy from that. But you have all the consequences - you have to create a pond, build the dam etc.
      • by FrankDrebin ( 238464 ) on Sunday April 11, 2004 @05:16PM (#8832601) Homepage

        yes, but just momentarily

        Huh? Let's not forget the law of conservation of energy. Of course a waterwheel/generator takes energy from the river as it puts out electrical energy. There is nothing "momentary" about it.

        But this energy is otherwise "lost" to heat as the water flows downstream anyway. IIRC it was Joule [] (whose energy scale we use today) that originally did the science on waterfalls, showing the water temerature at the bottom of the falls is higher than at the top. As water flows downhill, it pummels into itself, and the gravitation potenital energy is converted to heat.

        A waterwheel simply takes some of this energy and converts it to rotation instead of heat. With a waterwheel in place, the temperature of the water will be ever-so-slightly cooler downstream.

        The downstream reservoir has a level, and it is the difference between this elevation and the tailrace (water exit) elevation that determines the amount of energy the hydro plant can extract. The difference is called "head" (I kid you not).

        So the energy of the water used by a waterwheel is not "stolen" from the downstream plant... because it would have already been "lost" to heat as it reached the reservoir anyway.

  • hydroelectric power (Score:3, Interesting)

    by gordona ( 121157 ) on Sunday April 11, 2004 @03:32PM (#8831942) Homepage
    You'll probably have to divert some water through a small sluice, but you'll have to find out if you legally can do this. You can emphasize that it will be 100% conservative, ie., no water will be consumed. A turbine in the sluice can be geared to drive an generator at higher speed. Will no doubt have to play with the size of the sluice and the gearing etc, since you will have essentially no head to play with.
  • Wind Power (Score:3, Interesting)

    by Denix ( 125207 ) on Sunday April 11, 2004 @03:33PM (#8831946) Homepage
    I'm not an expert on this but I believe you would also get wind off the river. So you could combine water turbines and windmills.

  • Traditionally, the old grain mills used a big water wheel, which turned at a low rpm, to drive the mill stones.

    An undershot wheel, where the water goes under the wheel would work, if you can force the water under, and not around it.

    From there, simple gearing will give you what ever speed you need.
  • by gleekmonkey ( 737957 ) on Sunday April 11, 2004 @03:36PM (#8831964)
    Why not just use humans? Just make a computer based reality world to keep them happy, and harness the energy.
  • Do Some Homework (Score:5, Informative)

    by klausner ( 92204 ) on Sunday April 11, 2004 @03:36PM (#8831966)
    There is a huge amount of material from the 19th century on mill design, and how to get the most out of river power. Try doing some research in a major library.
  • Govt Regulations (Score:3, Informative)

    by codepunk ( 167897 ) on Sunday April 11, 2004 @03:38PM (#8831973)
    You may need to rethink that idea if you have any sort of state regulations like we do here in Wisconsin. Here you cannot make any sort of man made diversion, dam etc without drawing a serious amount of heat. It is quite likely you will run into the same sort of problems where you live as well.
  • by ramk13 ( 570633 ) on Sunday April 11, 2004 @03:38PM (#8831975)
    You either need water moving at a good velocity (kinetic) or some sort of height difference (potential) to generate a reasonable amount of power. (assuming you don't want a enormous paddle) I doubt you'll be able to dam the river in any way yourself without getting some sort of permit, because dams can have serious environmental impacts.
  • Permits? (Score:5, Interesting)

    by pherris ( 314792 ) on Sunday April 11, 2004 @03:40PM (#8831987) Homepage Journal
    While it does sound like an interesting idea I suspect that the county and/or commonwealth will want you to pull somekind of permit. After they stall you for a year or two just to come up with the regulations they most likely want engineering data concerning possible damage to the riverbed and the generator's effect on river currents. Of course this really makes no sense but local politics never did.

    Years ago my family spent a few years trying to get a 30' fix pier (that others on our street could use for free) built by our property. Between the hassles of the town, state and MEPA we gave up. Strangely a few years later a neighbor (and state senator) who opposed to our project build his own from our prints 100' away. I guess we didn't grease the right gears.

    My advice, make it small, discrete, quite and easily removable. Be forward that running your own generator over a long period is probable cause for the DEA to search your house as a suspected grow-op. It sounds crazy but again it's all about politics.

    Bonne Chance.

  • by zogger ( 617870 ) on Sunday April 11, 2004 @03:41PM (#8831993) Homepage Journal
    ... but there exists a tow-behind your sailboat generator I have seen. Looks like a dinky torpedo that is trailed behind, the little props spin, you get juice. It would do what you are looking for, easy to install, some power. Legalities of tying it directly to some point out in the stream-no idea, plus the safety factor of someone smacking into it.

    found it

    with that said, unless a stream goes entirely through your property, ie you can control both sides of the bank and build a proper dam etc, which is a ton of hassle and permits and whatnot usually, I would recommend doing the normal tried and true approach of wind/solar/fuel genny hybrid as an adjunct to your grid power. Re arrange where you put your money into first which of the first two works better for your locale. You usually want all four for true backup solution in most places. that is a generalization, but mostly true. It's really a variable, it has to be customized to your location and needs. Site survey maps exist on the web that will show mean average sun shiney hours and mean average winds for your area that will help you make a determination of which method gets priority. the reason why the "hybrid" approach is so good is that usually most places in the US get a lot of wind in the winter, but less wind but more sun in the summer. but that just depends, some places it's so windy all the time wind alone with the fuel genny backup is good, other places solar is better,etc--just depends..

    me = grid, some solar, backup aero-marine wind genny, two fuel gennys

    good luck! Once you get your rig up and working, you'll ask yourself "why the heck didn't I do this years ago?" It's really comforting knowing you always have SOME power no matter what, and even better to OWN it.

  • Let me ask a follow-up question to this. If one were to generate power this way and stay on the grid to try to feed back power and mak some income (as well as have power if your system greaks down), how do you keep your river driven system in sync with the 60 cycle grid (which obviously must be done if you plan on feeding the frid)?
  • what about building some kind of water-wing that, when placed in the water, oscillates from low position in the water to high position in the water - then somehow pull energy in off of that.
  • by unixwin ( 569813 ) on Sunday April 11, 2004 @03:41PM (#8831998) Homepage

    well here goes -- move
  • Is your land hilly? (Score:2, Interesting)

    by WindBourne ( 631190 )
    One thing that you can do is use a small hydraluc ram to move water up a hill. Once in a small, resivoir you then allow gravity to do its work. Nice thing about this approach, is that if you use a big enough pipe/ram, you can pump up enough water for using on other projects such as irrigation or a simple open flowing water stream.

    And for many here, the ram does not use electricity.
  • submerible generator (Score:5, Informative)

    by SuperBanana ( 662181 ) on Sunday April 11, 2004 @03:46PM (#8832027)

    Real Goods catalog sells a generator that looks like a boat trolling motor or a minisub thruster, only with a bigger propeller. You anchor it in the river, and it uses the large volume of water flowing past it. I believe the river still needs to be moving at several feet per second, and has to be at least 2 feet deep- we're not talking mountain stream here. Needs to be a -river-.

    The other way is to lay pipe along the river for quite some distance, to as low a point as possible. You need quite a bit of "head"(vertical delta) or a lot of waterflow; Real Goods' other generator system uses a turbine, with a customizable configuration of nozzles.

    As for selling electricity back to the grid (aka intertie systems)- you can't always do that(ie, "sell" the electricity back), and even if you can, there are often limits on how much electricity can be generated. The power companies also get pretty pissy about people powering the grid, because if there's an outage, and a lineman goes to work on the lines he thinks are dead...well...fried lineman. Most inverters these days designed for intertie(which is what we're talking about) have safety features to prevent it from powering a grid by itself, but power companies still like to make excuses and may demand one of their engineers check out the system(at your cost of course).

  • by AtariAmarok ( 451306 ) on Sunday April 11, 2004 @03:47PM (#8832038)

    Sneak out and clamp 12 to 120 volt convertors on passing motorboats, with wires going back to your house. The wires had better be long

    Stand on the shore with a big shotgun, and demand that passersby pay you a toll in killowatt hours in order to pass.

    Provide all the catfish with treadmills connected to generators.

    Per Max Screck [] of Batman 2, set up your own power plant and connect to the nearby hydro plants. Provide a lot of paperwork that no one reads, that includes the part that says that your power plant actually drains power from the grid instead of adding to it.

    Power hot air turbines from meetings of the Susquehanna River Basin Commission. []

    If all else fails, I'm sure that the orgone writings of Reich, the magic energy fields of Tesla, or the spoonbending force of Uri Gellar will give you an answer.

  • by StateOfTheUnion ( 762194 ) on Sunday April 11, 2004 @03:48PM (#8832046) Homepage
    If your relying strictly on the flow of the water (no gravitational potential energy due to elecation changes) you can measure the speed of the river flow get some idea how much head pressure the river can deliver. If it's a slow moving river (as you said in the header of the post) there may not be a lot of pressure head to deal with (which would imply a large volume of water to generate significant current).

  • by danharan ( 714822 ) on Sunday April 11, 2004 @03:48PM (#8832047) Journal
    Seriously, almost any solution will cost more than conservation. Not only can you have a smaller generator, but you won't need as many batteries to store energy for peak periods.

    Check out real goods [] and other suppliers. Good lighting, gas-powered hot water heaters, fridges and cooking... there are lots of nice appliances that can reduce your reliance on electricity.

    As for generation- keep your options open. It may not be legal for you to install a micro-hydro generator, and solar or wind might be cheaper.
  • by panurge ( 573432 ) on Sunday April 11, 2004 @03:51PM (#8832063)
    It was obviously written for settlers in the early 20th century and had all kinds of stuff on the different types of paddlewheels for different applications. By the sound of it you would need an undershot wheel with large buckets, unfortunately far from unobtrusive. Noise could be a major problem unless you used sucessive belt step-up drives rather than gearing, but the basic setup would need to resemble an automotive alternator system, which can produce a fairly constant output power despite fluctuations in rpm.

    However, there would be many potential problems, especially the difficulty and cost of fixing a large overhung wheel with an asymmetric load over a river with fluctuating height (the wheel axis is going to need to rise and fall) and the regulatory problems: I guess you would need a license and it might be hard to obtain.

    Another solution might be a hydraulic ram. There is the remains of one near where I live, that could raise water nearly 200ft. without an external power source, and was very simple and reliable. I guess some sort of license would be needed, but they are unobtrusive- there is nothing to see above water level but the exit pipe and the compression tank. Once the water is in a storage tank at high level, it can power a conventional turbine or an overshot wheel (more efficient than undershot), and the output can be adjusted to give fairly constant generator rpm regardless of load. Hydraulic rams can be noisy.

    However, I wouldn't recommend going down either of these routes unless you are a qualified mechanical or civil (structural) engineer or both, and have good contacts in other disciplines.

    The smallest hydro generator I have seen working, by the way, is at the end of the River Lyn in England. It's way bigger than you are likely to want ( I think I recall it's about 100KW) but when I was there in the early 90s it was still working. It attracts a lot of visitors from the US, and the whole place (including the water powered gravity railway) is a wonderful example of English quaintness.

  • by waytoomuchcoffee ( 263275 ) on Sunday April 11, 2004 @03:55PM (#8832091)
    You have Federal, State, and local regs you need to check out.

    First, Federal. The Corps of Engineers handles 404 permits. You need this to discharge dredged or fill material into waters of the United States - fill material includes structures as well. You might be exempt (usually if you affect under 1/10 acre you will be), but you need to make sure. If you are going to affect any Federal Endangered/Threatened species (are any in/near the river?) you will need clearance through the US Fish and Wildlife Department and or National Marine Fisheries Service. This is usually coordinated through the Section 7 process of your 404 permit, but if you DON'T qualify for a 404 permit and there are endangered species, you have to do your own Habitat Conservation Plan and prepare a document under the National Environmental Quality Act (NEPA).

    Second, State. The Pennsylvania Fish and Boat Commission regulates fish movements. "No dams, ponds, or other devices which prevent free migration of fish shall be erected or placed by a person licensed to propagate and sell fish in a stream flowing over the person's property".
    I am sure you also have some type of dam safety office as well, if you go that route. Also, I don't know how water rights work in your state, but you need to check into that as well. You also might have a state version of NEPA (many states do).

    Third, local. Check your local Planning department for applicable rules and regs.
  • Off Grid Living (Score:5, Informative)

    by Fortress ( 763470 ) on Sunday April 11, 2004 @04:07PM (#8832162) Homepage
    I would suggest that hydro power is not the best way to go for an off grid home power system. You really need high volume/high head water source to harvest any appreciable energy; from what you've described, there is no appreciable head (vertical drop) to the river near you. As well, as others have pointed out, building anything in the water entails a lot of bureaucratic red tape.

    I would say that solar or wind power is more feasible for most people. Solar is cheap in maintenance costs but expensive to set up, and you really need a lot of panel area to hope to supply your needs. Wind power is cheaper up front, but more maintenance is required because of moving parts, and noise from the rotors can be annoying.

    Either solution will require a battery bank to store power to use when the plant is not producing, plus a good inverter to supply consistent 120v 60Hz power. If all you are looking for is protection from outages, the battery bank with a generator may be ideal from a cost/benefit perspective. The payback time of most alternative energy projects is in excess of 50 years, so think carefully before you invest.
  • by caffeineboy ( 44704 ) <skidmore.22 @ o s u . edu> on Sunday April 11, 2004 @04:10PM (#8832189)
    If you can get access to both sides of the river, you could try rigging up a floating power generator. They seem easier to home-brew than a turbine, and are probably accordingly less efficient.

    There is a company in britaing that specializes in this kind of generator - one application that it lends itself to is water pumping from bodies that have a deep draft and a large amount of excess flow. nergy/ []

    I know that these are available from other places as well, and I'd be surprised if you couldn't make something like this yourself if you have a little motivation...

  • DEP Regulations (Score:5, Informative)

    by spenceM7 ( 683840 ) on Sunday April 11, 2004 @04:11PM (#8832193)
    Assuming you mean the Susquehana River in Pennsylvania, you have to deal with DEP permits. A quick glance at the regs indicated you'd need

    a) Dam Permit - application fee of $1500-$3000
    b) Environmental Assessment Approval - free
    c) Limited Power Permit for Hydroelectric - $5 application fee and $10-10000 annual fee (depending on capacity)

    Not to mention any local or federal regulations (did you check the EPA yet?) or the permits you'll need for construction, etc.

    There's also a 30-day public comment period before the DEP rules, and they estimate it will take 220 days or so to complete the paperwork.

    Reference is from the massive PDF found at Department of Enviromental Protection []

    In short, you probably don't want to build a dam.
  • Not feasible. (Score:3, Insightful)

    by /dev/trash ( 182850 ) on Sunday April 11, 2004 @04:42PM (#8832401) Homepage Journal
    The money you would spend in getting Federal, State, and local permits would offset any savings you would incur from being off grid.

    Since you said you are in the middle of nowhere I'll assume you are closer to NY than MD. Not that it matters, I'm just trying to think of a place that is in the middle of nowhere on the Susquehanna.
  • Grain Mills (Score:3, Interesting)

    by Ironsides ( 739422 ) on Sunday April 11, 2004 @05:09PM (#8832557) Homepage Journal
    Old grain mills were always built by the side of a river and hill. A bit of water would be diverted from a stream, to slew gate. It would then flow to the top of a 30 foot paddle wheel with buckets to keep the water in. The wheel turned a shaft that was then geared down to turning the mill wheel. If you have seen the movie 'The Princess Bride', they have something similar in there where they are torturing the main hero. The buckets are important as they keep the water in until they are horizontal, getting the most out of gravity. Something similar should be possible if you have a hill near you. If you can get a picture of the mill at Appomatix Court House you should be set.
  • Easy Method (Score:3, Informative)

    by Long-EZ ( 755920 ) on Sunday April 11, 2004 @05:38PM (#8832723)
    I saw some similar /. concepts to the design that popped into my head. Also some total /. crap.

    Build a floating dock. Very common for people living on the river. Make it as wide as you can manage without drawing attention. Eight feet would be good. If you have a lot of river frontage, you could even build two or three docks. The velocity is low, so you need to capture a lot of mass. This is kinetic energy, proportional to the mass and the square of the velocity.

    Put a paddlewheel across the downstream width of the dock, maybe five feet in diameter, with two feet submerged. Nothing high tech is required. This doesn't need the optimal vane shape of a high pressure hydroelectric turbine. I'd use a shape that sheds debris to minimize maintenance.

    Use a large belt around the outer diameter of the paddlewheel to drive an automotive alternator (very large gear ratio) with an external voltage regulator. This will cost about $20 at a scrap yard. Adjust the voltage regulator to produce 14V at the batteries to null the loss in the long wires, which should be at least 10 AWG. Use a circuit breaker at the batteries and the alternator. A charge controller will prevent overcharging if the regulator fails.

    Charge a parallel bank of 12 V deep cycle discharge batteries, as used in golf carts, small boats or RVs. These are available for a decent price locally. Sealed batteries are good. Low maintenance, and no worry about explosive hydrogen offgassing. Keep the batteries warm, but vented to the outside air.

    Use a power inverter to create 120 VAC. You can buy one that syncs to the power grid if you you want to sell power back to the utility, but I wouldn't bother. I'd cut the cord completely. You can buy inverters on eBay. Trace makes good inverters.

    An alarm should monitor battery voltage and possibly charge rate. If river debris jammed the paddlewheel, you'd want to know sooner rather than later. A true geek would have it email if there was a problem.

    I'd build a big cover over the paddlewheel assembly and maybe make it look like a barbeque grill or storage locker. I wouldn't go out of my way to inquire with the authorities. Better to beg forgiveness than ask permission. "Gee, I didn't know I couldn't generate my own power."

    You'll be surprised by how much energy you get from a small & slow moving paddlewheel. Unlike sun or wind, water power is 24/7, so your battery bank can be a lot smaller with a hydro power system. For about $500 initially and battery replacements and alternator brushes every few years, you can be off the grid. Most of us don't have a river and need to use solar.

  • by igzebier ( 582821 ) on Sunday April 11, 2004 @06:18PM (#8833044)
    Here's something that sounds just like what you're looking for:
    In the east channel of the East River, next to Roosevelt Island and in the shadow of the largest power plant in NY State, Verdant Power [] has been deploying a small farm of low speed turbines to tap the force of the tidal stream that flows back and forth in the channel.

    In the scale you're interested in, a ten foot turbine can power 25 homes.

    There is an article about it at the Roosevelt Island Wire website [].
  • Hydro Radio (Score:3, Interesting)

    by AikenDrumGotWired ( 566948 ) on Sunday April 11, 2004 @06:40PM (#8833220)
    Since the poster did not state which branch of the Susquehanna he lives near I am not sure of he is close enough to the location of
    for them to be able to render him any assistance or inspiration. WJFF is a public radio station that is run entirely off a hydro generator(water conditions permitting). It makes a nice little case study for those who say it can't be done, or for those who do not live in a state that has net metering laws, or one with intolerably cumbersome restrictions.
  • by Halvard ( 102061 ) on Sunday April 11, 2004 @06:52PM (#8833319)
    A sling pump doesn't use electricity to pump, rather the stored energy of the moving water. So use that to fill a tank at higher elevation feeding a small turbine. With a sling pump you just have to moor it (or tie it off to a dock) on a body of moving water. Check out Rife Ram [] for an example. I suppose if you were really industrious, you could use the runoff from the turbine to feed a hydraulic ram pump [] to fill the tank back up or another tank to, say, water the garden and lawn.
  • by rspress ( 623984 ) on Sunday April 11, 2004 @07:44PM (#8833714) Homepage
    The paddelwheel method is the way to go but actually putting it in the river would not be.

    More than likely this would be an illegal to do and dangerous as well. A better way to go would be a diversion channel that diverts a small amount of water from the river. At the top of the project or head would be a simple weir or gate to control the flow of water during the changing levels of the river. Depending on the amount of drop between the head and the wheel might give you higher speeds than the river itself could create. After the wheel you simply channel the water back to the river. The channeling back may be the hardest part of the project. As changing river levels might be harder to control and water may back up into the system. It depends on your situation. You may be able to gain a little elevation by using a shallower slope than the river has. Water needs at least a .15 of inch drop every 100 feet to move..and that is slow moving water.

    In any case, you would need to survey the job and use an optical level or a laser level to determine the drop between where you pull the water out and where you put it back in. This could be a costly project depending of the generating needs and your state laws, county laws..etc. But the way stated above is probably the only way to do it legally.
  • by Charcharodon ( 611187 ) on Sunday April 11, 2004 @07:55PM (#8833806)
    Take a look at =1200&sd=1201&ts=1017104

    They sell a product called the Jackrabbit. Orginally it was used for oil survey sleds that were towed. This way you could mount them without having to build anything elaborate to change the water flow. This should work nicely for what you are wanting.

  • by Anonymous Coward on Sunday April 11, 2004 @08:38PM (#8834088)
    If you google for "micro hydel iit" you'll find
    interesting hits on this topic. NOTE: Hydel is
    the Indian-English term for Hydro power.
    When I was working at IIT Delhi I interviewed
    a young woman who had just completed a research
    assistantship during which she and her professor
    developed a generating unit that would fit your
    requirements. They used a type of rotary pump
    that is mass-produced cheaply in India (used it in
    reverse of course), and they got good results.
    Unfortunately I wasn't able to hire the young
    woman, and I don't have any references for you.
  • by RubberJohnny ( 653235 ) on Sunday April 11, 2004 @08:48PM (#8834136)

    I don't know what the average flow of the Susquehanna is but I doubt it's really a slow river. I do know the Mississippi is typically moving about 4 knots and it is considered by boatmen to be an absolute bear to travel upstream. Recreational boating in the main Mississippi channel is near zero because the current's just too strong. I'm betting your river is faster.

    A sailboat (monohull recreational boat big enough to have a galley) is making fair time if he averages six knots. Six knots is enough to generate a helluva lot of electricity using a water generator (they call them "spinners" and some of them will convert to wind generators if you get the urge). These things are not even that expensive.

    Contrary to some of the alarmist nonsense being posted here, as long as you are not messing around in a wetland (swampy, boggy marshy place) and you don't propose to do any dredging, the Corps of Engineers presumes that all docks and piers for small boats will be approved for riparian use on ALL navigable waterways as long as you don't interfere with navigation. Possibly you have stronger local regulations, but get your COE permit and I think everything else will fall into place pretty easily. Sink a couple pilings, hang the spinners deep enough to keep from freezing and I expect you're in business.
  • by pr0cess ( 770458 ) on Sunday April 11, 2004 @09:36PM (#8834468) Homepage
    Some people build what's known as "microcentrals", which are esentially rotary water pumps working backwards. They make water flow into the pump so it turns the turbine and makes the engine act as a generator. I guess some modification is required to stabilize and clean the resulting current, but it shouldn't be too difficult to do. But no matter what system you're going to use, if you want a steady, reliable electric production you're going to need a water and some supplementary infrastructure (pipeline, energy dissipators, etc). That's where the city and environmental agency folks come in, and that's where it gets bumpy.
  • by John Murdoch ( 102085 ) on Sunday April 11, 2004 @11:30PM (#8835137) Homepage Journal

    You're in either Pennsylvania or New York. And you're on a river that has been actively dammed and controlled for over two hundred years. Which means that your property either has deeded mill rights, or it doesn't. And if it doesn't, you have no legal right to divert the water in the river to power a generator. Which is to say, attempting to divert river flow to generate electricity could get you in a world of trouble.

    What about in-river systems?
    Good question--and I'm sure that your state environmental agency will tell you. And I'd bet money their first answer will be "no." Bureaucrats are bureaucrats--and anything that is likely to cause them additional work is almost certain to be turned down.

    This doesn't mean you're dead
    What you can do to help grease the skids with your state authorities is to contact your local state legislator. If you're in Pennsylvania you'll find that a lot of legislators are extremely interested in "constituent service." Call the legislator's district office, and explain where you live (make sure you live in that legislator's district) and what you're trying to do. You want to know if the state has any information on the subject, and how you can go about finding out. You will be talking to an intern--a breathless, endlessly enthusiastic young person who is just itching to find answers. You may find it astonishing how quickly you will get answers--and since the question came from Rep. Stuffedshirt's office, the answer is far more likely to be "yes."

    Visit the county courthouse
    If your property at the river's edge shows any kind of swale or evidence of an old channel, go to your county courthouse and ask for the Recorder of Deeds office. Ask for help in searching for mill rights--and whether or not your property ever had mill rights assigned, or was subdivided from property that had mill rights. If the answer is yes, you should ask your county bar association for a referral to an attorney with experience in real estate law--what you're looking to do is assert that you want to take advantage of mill rights that were deeded with the property years ago.

    On the off chance that mill rights were awarded to your property years ago, you may be able to do this. In the more likely event that you do not already have mill rights, you'll have to do some design work, get a registered professional civil engineer, and go through a planning process that will include the state environment regulators, the utility company that owns the hydro dam downstream (most likely PP&L), and probably the U.S. Army Corps of Engineers. And unless you have a very long stretch of shoreline, you'll have to get permission from your neighbors to dig a mill race upstream, and a tail race downstream. (This, of course, means that you'll be providing them with free electricity too.)

    But what about a floating generator in midstream?
    If you're in Pennsylvania, good luck. The Susquehanna is full of boaters and fishermen, and the state is going to regulate you to death with concerns about who might hit it, how you'll secure it during the winter, and whether you have adequate insurance coverage for any possible liability.

    In short--I think you'll find that the licensing, permitting, and assorted legal folderol will make the project economically infeasible.

  • by Ricdude ( 4163 ) on Monday April 12, 2004 @01:01AM (#8835577) Homepage =1200&sd=1201&ts=1017104 []

    Jack Rabbit Submersible Hydro Generator

    No Pipes or Dams! Power from any Fast-Running Stream or Tidal Flow!

    The Jack Rabbit is a special low-speed alternator mounted in a heavy-duty, oil-filled, cast aluminum housing with triple shaft seals. Orginally designed for towing behind seismic sleds for oil exploration, this marine-duty unit is ideal for home power generation near a reasonably fast-moving stream. In a 9 mph stream (slow jog) the Jack Rabbit produces about 2,400 watt-hours daily. Ina 6 mph stream (brisk walk) it produces over 1,500 watt-hours. The 12.5" propeller requires 13" of water depth. A rock or timber venturi can often be constructed to increase stream speed and power output.

Never buy from a rich salesman. -- Goldenstern