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Thread: Every Hydro Installation Is A One-off

  1. #1

    Default Every Hydro Installation Is A One-off

    After filling my head with endless you tube videos, talking to Chinese providers I met through AliExpress, I've come to the realization that this is going to be a big project.

    The easiest part is the actual hydro unit. Apparently they are everywhere in SE Asia (does SE Asia include China?). Indonesia. Vietnam.

    There is, on the surface, not too much to it. You have the hydro generator, a unit that includes a drive wheel of some sort,, a penstock, which is the line heading from point A to B, a source of water above point B, and a load, so the generator doesn't run amok and self destruct. Wind has this latter problem too.

    Hydro electric is not an electrical challenge, at least not at my level of endeavor, but rather a mechanical engineering effort. You couldn't want a better electrical generation source, steady, consistent. Compare that to wind and solar.

    So,, no mppt controller, just something that won't fry the batteries, and accounts for the voltage drop in the line as the current increases and decreases, as the batteries come to full charge. At some point the dummy load kicks in,, a simple relay will manage that.

    I was going to use a large water heater I have, but I think that I will go with baseboard heaters instead. Cheap to buy, and this is winter after all,, I could use a little heat where I'm at.

    The problem with the water heater is,, once the tank is heated, I have no more dummy load. I need something more confiable,, expecially if I'm not there. Anyone can open a valve - - - - slowly,, water hammer can be destructive.

    In fact, that will be the most critical part of the design, making it Nica proof

    The most aggravating part of a hydro system will be avoided, almost in its entirety. THAT is the intake. That was the biggest problem my Sierra Nevada friend had, keeping his intake clean,, and probably the biggest problem MrHydroHead had with his unit throughout the 18 videos I've watched. OK,,, he had some other issues too, like when the creek washed out his penstock. But he redesigned his intake at least three times.

    Coming out of the bottom of my lake,, a screened intake about two feet above the lake bottom, I will avoid everything but a bit of waterborne silt. Nor will I have to deal with the temperature extremes of some installations.

    Only wanting 1KWH helps a lot. I currently have a 6" pipe coming out of the lake, and that flow is amazing to see. I'm going to use 4" sanitario as a penstock.

    Designing a steady and even fall that won't allow for an air pockets, and supporting the pipe securely, are my two challenges. Sweeps, instead of elbows, a lot of it is common sense, and due dilligence in supporting the penstock. A lot of people just put it on the ground,, and realize a lot of problems doing so.

    I have a long run to get the power back to the house,, but 1 KW ?? Copper #10 THHN should do it. I'll cover it with that cheap black manghera, I've had good luck with that.

    I'm a long way from a final plan.

  2. #2

    Default Re: Every Hydro Installation Is A One-off

    The first step in any project is gathering as much information as possible. This is especially true with a hydro electric project. I found a design firm in Utah who not only offered to coach me (probably in hopes of selling me the turbine), but whos website was a trove of good information.

    Particularly useful was their description of a Google Earth tool that describes not only the elevation between points A and B, but also the terrain. In most small installations I've seen, the penstock follows a more or less straight line, and the terrain is often challenging. Most often the penstock winds up being a PVC or polyethylene pipe that simply sits on the ground. This pipe is favored for its low internal resistance, a bit less than PVC, but requires a special tool to heat fuse the joined ends.


    If you have more head than you can need, I've seen corrugated plastic pipe used.

    Head is one of those "Be Careful What You Wish For" things. To a point it's wonderful, but beyond some reasonable number, it adds to the cost and the complexity for a DYI installation. 100 PSI is great,, manageable,, 350 PSI,, not so much.

    So, yesterday, The K Unit and CookShoe walked the path and took some pictures. While we still don't have a number for the lowest point because of the lack of signal in the bottom of the barranca and the tree cover, We were able to determine the fall to be between 150 and 200 ft.

    We also looked at another small dam in the second barranca. We built this dam from dirt filled feed sacks, covered with black plastic. It has a 4" drain, and we use it for irrigation.. The barranca drops steeply from this dam, to the lowest point on the farm,, and while it's only about a 30 ft drop, the flow when it rains would be huge. I would use 6" sanitario here,, and this would only be a viable option when it was actually raining. But, this water would not diminish the level of my lake.

    As you can see from the pic, the water is not clean like the lake water, so an intake would have to be built that kept the debris out of the penstock, and could be cleaned without too much trouble. The debris size has to be limited to less than the nozzle diameter of the hydro unit.

    One huge advantage I have over a larger,, more conventional hydro installation is, voltage regulation and frequency control is not important. I am just charging batteries. The power from the hydro generator will be rectified and fed to a controller anyway, so anything between 65VDC and 110 VDC.

    I am looking at obtaining a larger generator alternator, one capable of generating close to the capacity of my head and flow, and run it at a lower speed. The alternators are rated 500 to 1500 RPM, so for those times when I didn't need that much power I could adjust the opening of the valve to obtain more, or less. I'm uncertain about this concept, and understand that the alternator will be considerably less efficient at the slower RPM.

    I posed the question about the feasibility of this concept to Alison,, my Chinese connection. Their bread and butter is 30 - 100KW installations, but they also manufacture 1KW to 5KW units, which look like they use the same casting. Nozzle(s), runner, alternator head size, and penstock fitting would be customized to obtain the power output desired. The difference between the various units is small, running from $630 for 1KW to $1280 for the 5KW. My target point was 1KW.

    We're still early on in the planning stages, and there is much more to learn.

    Pics: The K-Unit taking photos and verifying elevation numbers; the view up the mountain and watershed below it; the view down into the barranca that I dammed to make the lake; and the second dam that I could possible utilize when it rains heavily

  3. #3

    Default Re: Every Hydro Installation Is A One-off

    So,,, moving on.

    My big question at the moment is whether I can purchase a larger head,, for example 2KW, and run it at a lower speed for less water consumption when I require less power. The power generated is a function of head and water flow. Intuitively, one would assume that this would be the same as it is for wind.

    A wind turbine will generate some small amount of power at a modest wind speed. However, most wind turbines generate their rated output at 24 - 27 MPH. Five blades do better at modest speeds; three blades do better as you approach the rated output. Most wind turbine manufacturers claim "cut in speeds " of 5 to 10 MPH,, but the power generated is very modest. There is no free lunch,, despite what AOC and her commie friends would have you believe.

    So one would assume that it would be the same for water. The kicker here is you match your nozzle to the combination of pressure and flow to get the maximum efficiency. So not only will you be turning your alternator in the turbine at a lower rpm, but the jet of water striking your wheel will be less than optimum.

    It's done,, varying water flow,, within reason. Mr HydroHead tunes his penstock valve to get exactly 60 hertz from his turbine. But, he's pulling 9 KWH to heat his snow covered Colorado mansion. So, when he turns on the microwave, the frequency probably drops a hertz or two,,, but what's a few hertz among friends ?? The majority of the small hydro users charge batteries. Their alternators generate 3 phase AC which is rectified to DC. The load is more or less steady, into the controller/charger, and when the batteries are charged,, the load is dumped . . . somewhere. Water heater, baseboard heater,, or just big air cooled wire wound resistors.

    Wind and water share this dump load need. Without a load the wind turbine blades will rotate to a speed that is self destructive,, and the same for the generator in the water turbine unit.


    There has been some experimentation with variable nozzles, but the integrity (shape) of the stream that leaves the nozzle and strikes the "runner" as the wheel is called, is also important. Like the stream that comes from the classic adjustable brass garden nozzle,, there is some precise point where the stream of water achieves the maximum distance. The point where the nozzle delivers the best combination of flow and pressure

    There are relatively inexpensive motorized water valves that could be used to shut off the flow of penstock water, but this would require a minimum of another wire pair, arriving from the other side of the controller. One could sense the increasing voltage at the turbine head as the batteries reach full charge and actuate the valve motor to shut off the penstock flow. But,, without some "indication" from the other side of the controller,,, the valve is not going to turn itself back on.

  4. #4
    TRN Science officer bill_bly_ca's Avatar
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    Default Re: Every Hydro Installation Is A One-off

    Did you watch the dirtbag hobbit's implementation of 4 jets, 3 of which are gated?
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  5. #5

    Default Re: Every Hydro Installation Is A One-off

    Quote Originally Posted by bill_bly_ca View Post
    Did you watch the dirtbag hobbit's implementation of 4 jets, 3 of which are gated?


    Yes,, I saw that. The guy is a real renaissance man. With an unlimited budget to do it his way. I've looked at several of his other videos.

    I have neither the welding skills,, nor the time to make that work. For the money, I can buy two of the Chinese units, a 1 KW and a 2 KW

    As I remember he was finally getting about 500 watts out of his unit. He made one important point,, that had not occurred to me: those things are really noisy.

  6. #6

    Default Re: Every Hydro Installation Is A One-off

    BillyBly got me to thinking. After my experience with the solar planta,, I learned a lot, like, leave yourself open to future changes, additions.

    And build the electrical system so it is robust enough to accommodate wind and solar.

    It's kind of curious how the needs of a small user mimics the macro needs of the grid in the US. Solar is great, getting cheaper, and gigawatts of solar are being installed world wide.

    But,, like in Nicaragua the sun only shines during the day,, and not even all days. Here in Tucson they are covering parking with solar roofs, but it's not as universal as it could be. We have the sun, but my electricity only costs me 9 cents a KWH. When I left California several years ago,, I was paying 25 cents.

    To my point, I need a combination of solar, wind, and hydro (since I have the resource). And, a little bit of fossil when everything goes south.

    Nuclear is currently off the table unless I stumble across a surplus submarine nuclear plant on one of the Defense Department liquidation sites.

    Getting back to the point,, finally, I need something that will allow me to re-jet the water impulse and change the power output of my unit to meet future needs. The hydro turbine is the smallest part of the investment in just about every hydro installation. A small additional investment now will enable me to plan for a future need, such as supporting the flood of expats from the US flooding to Nicaragua and buying a lot on my bench with it's beautiful views over the Rio Coco towards Honduras.




    These are my two options. The one above will lend itself to future enhancement. The one below is cheap,, I see prices FOB China as low as $270, easier to install. Of course, at that price I could just buy one,, and chuck it when and if I actually do need more power.

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