Building A Generator That Runs Off Hose Power

[Paul Junkin] bought a curious product off the Internet. It was supposed to generate electricity when hooked up to a running hose. Only, it didn’t do a very good job. His solution was straightforward—he built his own hose-powered generator that actually worked.

The design uses a turbine hooked up to a small motor acting as a generator. To maximize the transfer of energy from the stream of water to the blades of the turbine, the hose is hooked up to a convergent nozzle. [Paul] does a great job explaining the simple physics at play, as well as the iterative design process he used to get to the final product. He calculates the best-case power coming out of his hose around 50 watts, so for his turbine to collect 22 watts is a win, and it’s good enough to charge a phone or run some LED lighting.

Of course, this isn’t a practical generator if you have to pay for the water, and there are other solutions that will get you less wet. Still, credit where it’s due—this thing does make power when you hook it up to a hose. We’ve seen some slightly less ridiculous concepts in this space before, though.

 

68 thoughts on “Building A Generator That Runs Off Hose Power

  1. This is the first step for making your own hydropower plant. A typical water hose has about 40 – 80 PSI of pressure, which is something like 100-200 ft of “head” or elevation. If you have a stream uphill and you build a weir and a small settling pond to keep the debris out, you can basically pull a garden hose downhill and get 20 Watts of free power.

    You can do it with less head height and/or get more power if you increase the pipe diameter and build a bigger turbine. A kilowatt is not outside of the realm of possibility.

    1. Create a piston engine like steam engine or air pressure &motor and use the whole 2 to 3 bars water pressure to drive a generator. Should work. You still can use the water as well.

    2. I have friends that live in Montana in the Bitterroot valley on a mountain side and above them is a Creek. they went up about 200 and feet in elevation about 400 foot distance into a 3 inch water pipe and push an alternator with vanes similar to a waterpump in reverse with water from the creek And are able to generate about 1000 W for their home they have no other commercial source of electricity and live too far from the grid. They have some solar panels and diesel power generators to make up the shortfall.

  2. Would be interesting to do the math and work out the efficiency difference of a power transfer like this between the pumping station and you using both a pipe with water pressure and regular power lines

    1. So you want to compare the difference in efficiency between transferring power by water and by electricity?

      Simple: electric grid efficiency is typically 95% or thereabouts within the typical transmission distances (under 200 miles), and this is less than 40% given the pumping losses in the water grid.

      But consider, back in the early days of electricity, they were considering using pressurized air to transmit power over long distances as an alternative to Edison’s DC system. Apparently the efficiency was comparable beyond a few miles.

  3. Since this is a pelton wheel turbine, there are some tips and tricks worth mentioning.

    To get the most efficiency out of it, you need to match the turbine diameter and speed to the stream exit velocity and your generator load. The maximum efficiency point is when the spoons are moving at exactly half the speed of the jet velocity, so you need to load up the generator to the point that it’s running at this speed.

    Then, if you’re getting a lot of sideways splashing, you need to increase the spoon depth and width enough that the water stops spraying to the sides. You know you’ve reached the maximum possible efficiency for your head height and flow rate when most of the water is just dropping straight down from the turbine wheel. If it’s spraying backwards, you’ve overloaded it, and if it’s splashing forwards then you’re running too fast and not extracting the maximum energy possible.

    1. “Since this is a pelton wheel turbine, there are some tips and tricks worth mentioning.”

      And if you add a Peloton to the pelton, you could convert more energy to electricity!
      B^)

  4. A while back I went through the arithmetic of how much electricity this would generate from my domestic water supply, and how much it (the water) would cost. It came out to 50 watts maximum, at $60/kWh. That’s right, sixty dollars per kilowatt hour.

    I’d be better off buying peanut butter and peddling on a bicycle generator. That’s only $10/kWh.

      1. This is the kind of thinking that needs to be applied though.
        We’re so focused on finding singular, big solutions, when what we could be doing is creating critical mass of energy reuse everywhere in small bits. So while this would run your house, you’d maybe hook one up when you need to use the water only.
        Just like the Archimedes turbines that aren’t that efficient, but add them anyway, every single item decreases energy reliance and increase re-use.

    1. it’s a lousey alternative to the electric grid but it can be really handy when the power goes out. there’s a consumer device that provides an emergency sump pump. it uses your pressurized water supply to provide power to lift water out of your sump pit. roughly, it spits out twice as much water as it takes from the municipal supply — half of its output comes from your sump. so if a storm knocks out your electricity and also fills your basement with water, you still have an option. especially handy if you can’t safely restore electricity until the water is gone :)

      i worry about that kind of thing a lot…my hydronic heat is fueled by natural gas (which is relatively more reliable) but requires about 50W to run a pump and some solenoids. if the electricity goes out for more than a few hours from an ice storm, having a backup 50W supply could be the difference between my pipes freezing and not, regardless of the cost. probably should just get an inverter to hook up to the car for emergencies though..

      1. I installed one of these pumps after a storm knocked out power in my neighborhood and it was out so long that even people with battery backed pumps had their basements flood. It works extremely well. I forgot to put hammer arresters on the water line, so it clunks when it runs. However, that makes a nice alarm to tell me that my electric sump isn’t working. Recently, my electric sump died and the hammer told me that it needed to be replaced.

          1. I could get several of these and use off my well pump. As the water is free I would not have any expense. Except for the troublesome second law of thermodynamics.

    1. You’re taking it too seriously.
      BTW, how did you get the Halloween marks on the pennies?
      They look cool!
      (I don’t have an Instagram account, and was kicked off Facebook, so I couldn’t explore your link further)

    2. Obviously the city water pipe is the least efficient energy transport imaginable. The point of most home hydro generators is to hook them to a hose running down from a stream at a much higher elevation, althougb with enough water flow it only needs to be a few feet. They generally only power a couple light bulbs, so not really worth buying new equipment.

    1. I had a neighbor in the apartment above me who decided the cheapest way to heat her apartment was to leave the free hot water running all night down her sink. Unfortunately, she also broke her sink drain, so it flooded my apartment. So in addition tk costing hundreds in wasted water heating, it also cost thousands in building repairs.

  5. Worst idea ever. Find something useful to do. The water is more valuable than what little kw you are generating with this inefficient process. Hook it up to a stationary bicycle or something.

  6. (Sorry for the wordiness. TLBS — meta confirms that pointing the hose downward with a 20 foot drop will increase generator efficiency by ~ 14.4%. Further discussion with meta revealed that there might be a problem with terminal velocity. Not sure if this reasoning is correct.)

    [me]

    meta, I have read of how someone used water pressure to create an electric generator. The equation involved is: Power (Watts) = 746* Water Flow (GPM)* Pressure (PSI) / 1714. The setup involved shooting water to a wheel that then turned. Instead of a horizontal spray would it makes more sense to have the hose pointing downwards to capture the effect of gravity?

    [meta (LLM reply)]

    What a fascinating project! I’d be happy to help you explore this idea.
    First, let’s break down the equation:
    Power (Watts) = 746 * Water Flow (GPM) * Pressure (PSI) / 1714
    This equation is a variation of the hydraulic power equation, which relates the power generated by a hydraulic system to the flow rate, pressure, and efficiency of the system.
    Now, regarding your question: would pointing the hose downwards capture the effect of gravity and improve power generation?
    The answer is yes, pointing the hose downwards can potentially increase the power generated by the system. Here’s why:

    Increased pressure: By pointing the hose downwards, you're effectively increasing the pressure of the water jet due to the added weight of the water column. This increased pressure can lead to more power being generated.
    Improved efficiency: With the water jet pointing downwards, the energy transfer from the water to the wheel might be more efficient. The water jet will hit the wheel with more force, which could result in a more efficient conversion of kinetic energy to mechanical energy.

    However, there are some factors to consider when implementing this design change:

    Wheel design: The wheel design might need to be adjusted to accommodate the changed angle of the water jet. A more vertical wheel or a wheel with a curved surface might be necessary to maximize energy transfer.
    Structural integrity: The system's structural integrity must be ensured to withstand the increased pressure and force of the water jet.
    Flow rate and pressure: The flow rate and pressure of the water supply might need to be adjusted to optimize power generation.

    In conclusion, pointing the hose downwards can be a good idea, but it’s essential to carefully consider the design implications and potential challenges to ensure a safe and efficient system.

    [me]
    meta, In this setup the values are GPM=2; PSI=60. How much might the PSI increase if you added a 20 foot drop for the water until it hit the water wheel?

    [meta(LLM reply)]:

    To estimate the increase in PSI due to the 20-foot drop, we can use the following equation:
    PSI increase = Height (ft) x 0.433
    where 0.433 is the conversion factor from feet of head (pressure) to PSI.
    Plugging in the values, we get:
    PSI increase = 20 ft x 0.433
    PSI increase ≈ 8.66 PSI
    So, the total PSI at the water wheel would be:
    Total PSI = Initial PSI + PSI increase
    Total PSI = 60 PSI + 8.66 PSI
    Total PSI ≈ 68.66 PSI
    Keep in mind that this calculation assumes a static column of water and neglects losses due to friction and other factors. The actual increase in PSI might be slightly lower.

    1. Good God, Freedom units sure make that a painful exercise. I’m certain units like that contribute to sloppy thinking due to the ‘magic’ conversion factors with inconsistent and arbitrary unit conversions used. Maybe that’s a reason why the US is the worst in the G7 for numerical literacy.

      1. In my home country of Smugistan we have invented superior form of measurements that make idiotic metric and imperial systems look like systems for dumb babies. Not even smart babies. Dumb babies.

        Every unit is called a Smug. Here’s an example that even dumb European and American babies can understand: if you want to measure how much air is in typical Smugball (superior sport to your football), you calculate how much compressed Smugs go into ball. Once you get 100 Smugs, you start over at 0. See? So simple and superior.

        Smugistanian air also superior air. Needs less to fill same volume of space.

  7. “Of course, this isn’t a practical generator if you have to pay for the water, and there are other solutions that will get you less wet.”

    Funny how different cultures are.

    Because I didn’t care a bit about money here, it was the idea of wasting precious drinking water that hurt my heart when reading this.

    If it’s being collected in a rain barrel or being used to water plants, trees etc then it doesn’t hurt so much, though.

    Also, it’s cool as a proof of concept, of course. 😃

    1. The concept of “wasting water” is sometimes ridiculous in countries where there isn’t a lack of clean water. It doesn’t get “used up” – it comes from a river or a lake and goes back to a river or a lake. The real concern is that the companies that pump or sell the water have priced the service at some fixed monthly amount that far exceeds the actual cost of pumping the water, and they want people to draw less water so they’d get more profits out of it.

      1. There are ground water levels that can fall and rise, for example.
        During a hot summer, for example, waters in certain ground layers can be used up quickly in a given region. So there is a shortage.
        Not permanently, but for a while until the levels have normalized.
        Rain, for example, needs to pass through several layers of coal until it’s down there.
        The coal layers act as a filtering, too, which is a good thing.

      2. There must really be differences in education or parenting or something.
        In my school days, most if not all teachers did tell us how precious water is.
        That it means life (literally) and that we should never waste it.
        We were scoulded for wasting water in class room when we washed the sponge and simultanously had left the water tap running too long and so on.
        My geography teacher even statet that the west (we) do exploit nature and that water is more precious than mineral oil.
        Not in terms of something trivial as money, but being an important good for all human kind.
        We learnt how temperatures will raise during 21th century and that there might be wars over drinking water eventually.

        1. I live a mile from Lake Superior and our city water comes from a pipe in the lake and the sewage goes back out there. Our water rates are several times higher than Las Vegas and Phoenix, which are places with severe water shortages. Shouldnt places with virtually unlimited sources of clean water be paying lower rates?

          1. Our treated sewage goes back into the river, to be collected, treated, then drunk by the poverty struck citizens of Los Angeles.
            LA richers get their water shipped in.

            Call flushing, ‘Fixing a drink for Hollywood’.
            Upriver?…We must wage ware on them!

            Your water rates reflect that the pipe system was ignored for decades.
            Common in the rustbelt.
            Now you have to pay, and pay again.
            You know how city government works.
            Many incompetent nephews need jobs.

            This is a simple case of not everybody lives where you live.
            Water is INXS in many places.
            Pressurized clean water, not so much.
            Thawed water?

            IIRC an average of 2.x people are killed by falling icicles in Chicago every year.
            Good fun.

        2. Not in terms of something trivial as money, but being an important good for all human kind.

          They were employing the same sort of wisdom as telling children to finish all of their dinner because there are starving children in Africa. It’s a complete non-sequitur. Saving water here and now where there isn’t any shortage doesn’t somehow save it for other people in other places, or for the future for that matter.

          Their point was just to scare you to behave, as children would otherwise tend to leave the tap open and run outside to play without any care.

          1. “There are starving children in Africa” is a perfectly decent way to present the idea to a kid that some resources only appear to be plentiful because they’re unevenly distributed and they are one of the fortunate ones. It’s much too difficult to go into the logistics of actually trying to equally distribute food with your picky child every mealtime.

            There’s at least a couple of good reasons to point out that some people are starving. First, you’re right that it can help get them to behave, especially if it gets them to realize they are taking the food for granted / (undervaluing a resource due to their personal bias). Second is about the common answer “so give it to them / they can have mine!”. While food that is already on your kid’s plate may either be thrown out or eaten, but not given to the kids in Africa, if your kid throws out what you give them and then consequently they eat something else later on, then that can affect the overall supply of food, even if it’s complex and it doesn’t directly take food from someone else’s mouth.

            As for saving water for others or for later, that’s exactly what we do with groundwater, with the flow of rivers, the levels in lakes and reservoirs, etc. The level of groundwater can even drop in regions like New England which generally get a large water budget versus their losses. You just need to have usage exceed supply for long enough that the buffers reduce and people notice the water becoming scarce. It’s only in places where the water is still solidly in excess and that excess is not exported to other places that it doesn’t really make as much difference, and at least if nothing else it still costs energy or resources to meet the demand for pumping and filtering.

  8. Pelton turbines can reach usually more than 90% efficiency. They are used since a long time (1879) in mountain areas to produce electricity. There are some in my area.

    Building a Pelton turbine in 3D plastic and a garden hose with less than 50% efficiency is a proof of weird concept.

    Some more serious stuff : https://hydroturbine.info/

  9. I think its an awesome project. I for one was surprised that a small water stream like that could produce 22W. And mostly 3D printed no less. I think there are deffinetly applications for this when you will be using the water anyway (like irrigation), or when you have a source of non-potable water.

  10. More productive endeavor?

    Debugging overflow and underflow detectiom of 64 bit addition.

    1 Numbers are stored with most significant bute at high address and
    least significant byte at low address.

    2 Numbers are stored in twos complement.

    No subtraction! 2 – 3 = -1 is 2 + (-3) = -1.

    Reason: Computation of changing number sign i taking the one complement, then add ing 1.

    3 decimal is 011 binary where leadiing 0 is the sign. + = 0, 1 = -.

    Ones complement 0f 011 is 100. 100 + 001 = 101. This is the negative two complement of 3.

    The sum 101 + 010 = 111.
    0
    To see what the negative sum is as a positive number 111 – is 000 + 1 = 001 binary which is 1.

    ~All Computer arithmetic hardware engineers chose two complment becuase there is only addition, no subtractio

    if((c[7]&0x80)==0x00)
    {if((b[7]&0x80)==0x80){printf(“\n Underflow\n”);}}
    if((b[7]&0x80)==0x00)
    {if((c[7]&0x80)==0x80){printf(“\n Overflow\n”);}}
    b[] in aximum positive 64 bit integer.
    a[] is 1.

    Adding 1 to the maxiimum positive number causes an overflow?
    a[] = 01000000:00000000
    b[] = ffffffff:ffffff7f

    Overflow

    c[] = 00000000:00000080

    a[] snf b[] are two largest postive integers.

    Overbflow causes?
    a[] = ffffffff:ffffff7f
    b[] = ffffffff:ffffff7f

    Overflow

    c[] = feffffff:ffffffff

    a[] = -1 in twos complent.
    b[] is the smllest negative number in twos complment.

    The sum causes an underflow to the most positive number?
    a[] = ffffffff:ffffffff
    b[] = 00000000:00000080

    Underflow

    c[] = ffffffff:ffffff7f
    a[] and b[] are the smallest negative number.

    Tne sum causes a uncerflow to a 0 with a positive sign?
    a[] = 00000000:00000080
    b[] = 00000000:00000080

    Underflow

    c[] = 00000000:00000000

    add: c[0] = a[0] + b[0]; // no carry on first digit
    aa = a[0] + b[0]; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[1] = a[1] + b[1] + carry;
    aa = a[1] + b[1] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[2] = a[2] + b[2] + carry; <
    br> aa = a[2] + b[2] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[3] = a[3] + b[3] + carry;
    aa = a[3] + b[3] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[4] = a[4] + b[4] + carry;
    aa = a[4] + b[4] + carry; carry = 0 ; if (aa > 255){carry = 1 ;}
    c[5] = a[5] + b[5] + carry;
    aa = a[5] + b[5] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[6] = a[6] + b[6] + carry;
    aa = a[6] + b[6] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[7] = a[7] + b[7] + carry;
    aa = a[7] + b[7] + carry; ;
    if((c[7]&0x80)==0x00)
    {if((b[7]&0x80)==0x80){printf(“\n Underflow\n”);}}
    r> if((b[7]&0x80)==0x00)
    {if((c[7]&0x80)==0x80){printf(“\n Overflow\n”);}}
    goto *array[3];aa = a[0] + b[0]; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[1] = a[1] + b[1] + carry;
    aa = a[1] + b[1] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[2] = a[2] + b[2] + carry;
    aa = a[2] + b[2] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[3] = a[3] + b[3] + carry;
    aa = a[3] + b[3] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[4] = a[4] + b[4] + carry;
    aa = a[4] + b[4] + carry;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[5] = a[5] + b[5] + carry;
    aa = a[5] + b[5] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[6] = a[6] + b[6] + carry;
    aa = a[6] + b[6] + carry; ;
    carry = 0 ; if (aa > 255){carry = 1 ;}
    c[7] = a[7] + b[7] + carry;
    aa = a[7] + b[7] + carry; ;
    if((c[7]&0x80)==0x00)
    {if((b[7]&0x80)==0x80){printf(“\n Underflow\n”);}}
    if((b[7]&0x80)==0x00) {if((c[7]&0x80)==0x80){printf(“\n Overflow\n”);}}
    goto *array[3];

    The gcc c compiler is doing most of the work … not the nanocomputer. :)

  11. While this is impractical to merely generate power by using up water, this project reminds me of thermal generation of electricity using what would otherwise be waste heat, from a wood stove or fireplace. For someone who needs to use the water for necessary purposes, such as filling a pool or watering a garden (or being forced by a HOA to water their lawn), this represents an additional benefit from the expended water.

    Note that the local water utility is using energy to generate the water pressure of the water coming out of the faucet. So a downside of this project, if used frequently by nearly everyone in a neighborhood, is the increased cost of electricity for the water utility, possibly increasing water prices beyond any benefit from the home hose electricity generator.

    1. I think you’re on the right track here. A lot of people are having negative knee-jerk reactions to the video itself but my initial thought was… what if you built this inline to your home water system, you could gain trickle charging power at an expense of loss of water pressure without wasting water? Just a thought 💭

      1. That’s the way to go, put a small turbine instead of pressure reducing valves anywhere with reasonable water flow. For example on the input side of water reservoirs, when the water source is way uphill. Or on the toilet to power the fan for fresh air (and a quick fill valve, if you have to flush twice).

  12. Sure it’s ridiculous but I can top it.
    Why waste water spraying it through a turbine.
    After all water is mostly hydrogen the same stuff the sun runs on.
    If big oil didn’t suppress it we could power the whole world with water!

  13. I’d just like to point out that in the UK this would be illegal, because it is theft of power.
    The water pressure comes from pumps and the power to those pumps is paid for by the water company.

    1. The UK jails people for mean tweets and has banned pointed sticks (but not tigers, bananas or 14 ton weights).

      Get out, while you can.

      The humorless festering Cs have taken the bard of comedy (Benny) off the tube.
      Yet they still expect TV and cat fees.
      Deserve nothing but a swift kick in the crotch.

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