DIY Wind Turbine for Where the Sun Doesn’t Shine

There are plenty of places outside where you may like to have a project requiring electricity that may not get enough sun for solar power to be viable. Perhaps wind power could be used instead? [Greg] has a project to create a platform for using a small wind turbine to generate the power for your projects.

The wind turbine that [Greg] designing is a Savonius-style wind turbine that would put out between 5 and 12 volts. In a Savonius turbine, blades are mounted on a vertical axis allowing for a smaller, less complicated build than traditional horizontal axis wind turbines. The design is named for its inventor, Finnish engineer Sigurd Johannes Savonius.

After doing some research, the design will have a 2:1 height to blade ratio and use three pairs of overlapping curved blades stacked on top of each other, each pair offset by 120 degrees. This design, [Greg] figures, will come within a few percentage points of the efficiency of more exotic blade shapes while making the windmill easy to design and implement. Being half cylinders, the blades can easily be made from existing objects cut in half – pop cans, for example, but there has been some designing the blades in Fusion 360 for 3D printing. The stator board has been designed and the initial prototypes of it and the rotor have arrived, so the testing can now commence.

Once the design is finalized and the prototype working, it’d be interesting to see some projects start showing up using wind power instead of solar power. Take a look at this design for a vertical wind turbine, and this design for a simple, straightforward turbine.

 

25 thoughts on “DIY Wind Turbine for Where the Sun Doesn’t Shine

  1. Nice one, like the idea of the offset design re wind dynamics, would be interested in seeing simulation and site data logging those odd details to explore correlations in respect of maximising efficiencies whilst reducing manufacturing expenditures, will be looking more closely at these types of “oil drum” designs which were done in remote country (bush) in Australia over last 30 years…
    FWIW: Have a substantive paper design for a cheapie savonius variant for rural regions in Australia with a knock down rough type which could easily be made in third world from scrap parts such as discarded washing machines. Now comes the hard part of making mechanical progress conform to that egregious mix of static paper and dynamic self-critical review…
    For ref: https://en.wikipedia.org/wiki/Savonius_wind_turbine

    Thanks for post, good reminder overall and for me to put more effort in other projects too :-)

    1. I think that oil barrel design could be implemented on many islands in the world where there are a lot of discarded oil drums, having delivered heating/diesel fuel and considered uneconomical to replace.

  2. Why would the open-circuit voltage even be remotely interesting? What is the estimated *power* at various wind speeds?

    Also, I find it hard to believe a semi-circular bladed Savonius, which is a drag-based turbine, and not exactly known for it’s efficiency, would be anywhere near as efficient as properly designed lift-based wind turbines.

    Obviously, such vertical axis turbines have their specific advantages, mostly being cheap and simple to construct, but don’t claim they are almost as efficient without at least experimental data and/or CFD (computational fluid dynamics) simulation. Wishful thinking isn’t data.

  3. I am underway building one of these out of barrels. From what I have read you get lower speed and higher torque with the Savonius turbine. In my design I plan on using a thin rubber belt to drive the generator faster than the turbine speed and running that into an mppt controller. My requirements are mild, pumping 10 or so gallons of water out of a pond every day and into a nearby stand tank. I have also pondered getting rid of the electrics all together and trying for an all mechanical solution with the turbine driving a piston pump.

      1. The problem with that is that I would pretty much have to design the piston pump from the ground up. It would be more efficient but require more hand made parts. The electric solution is more out of the junkbox.

        1. You could grab an existing piston pump, then gear the output of the barrel turbine to match the required speed/torque of the pump. You can calculate the expected power output of your barrel turbine using the wind averages from https://www.currentresults.com/Weather/US/wind-speed-city-annual.php and get the expected power output from http://users.xplornet.com/~rmanzer/windmill/rotor_calculator.html . Your power requirements depend on how high you’re pumping the 10 gallons. You’re likely to have more efficiency from a mechanical setup, since there would be no parasitic load.

          1. True, but the disadvantage of a mechanical solution would be that it may not start at all in low wind speed conditions, especially with a two-blade design, which has a large torque ripple. An electrical generator could be much easier to start, and provide a small charge current into a battery for a long time, when the pump (that draws more power than the turbine can provide at any time) only runs intermittently.

            If properly designed, the parasitic draw of the electronics can be very small (on the order of milliwatts), which can be easily offset because you can do maximum power point tracking, which attempts to optimize the efficiency of the turbine. Of course, there are still several power conversions involved, mostly in the generator, battery and motor, each of which involves a power loss.

            The main arguments for a fully mechanical solution, in my opinion, would be the simplicity and reliability.

          2. +1
            Good links :-)
            Wish there were details for where I live in Western Australia. For a mechanical connection in respect of overcoming starting inertia perhaps a form of viscous coupling with a rheological fluid. Though I am in favour of an equivalent to the MPPT solar approach as applied to manage the chaotic aspects of wind but, to accommodate some adaptation to different wind turbine types too. Also a lot easier if there is some distance between power source and load and offers storage via batteries. With efficient brushless alternators/motors these days and at appropriate voltage selection overall utility and flexibility likely comes out on top, of course depends on budget and customer environment.

          1. Yes, me too. I was thinking of using a piece of common PVC conduit pipe, just repeat-print a snug-fitting screw section that keys top and bottom at the axis and press-fit them in with a smear of silicone sealer on the screw blade where it touches along the pipe wall, then rotate the whole pipe on external bearings at each end. I can’t see why it shouldn’t work.

          2. If you have a source of moving water you can build a water powered spiral pump. I did that year ago in another part of the property. The advantage of a spiral pump is the diameter of the spiral can be less than the lift height, and you can put spirals on both sides of the paddlewheel.

            The problem with an existing pump and gears is first of all, it is hard to find an existing pump for free or near free and gears are messy. I like the idea of a belt much better. With the electric I have a lot of options from trying to directly power a small boat bilge pump to charging a car battery and using an inverter to run an old sump pump. I have old car batteries and I have a a few inverters kicking around.

            It is a weird amalgamation of what I have and what I can get free or cheap.

            The greenhouse for example is built out of old sliding glass door panels for the roof and used 6 mil plastic and old pallets. I have like $23 bucks in the plastic and I still have over a half roll left, and the cost of air staples and air nails. The rest it totally recycled.

            The windmill will be similar. The turbine is built. Barrels cut in half and welded together, a car wheel axle bearing and a home made pulley. I have a bunch of PM DC motors, I plan on using one or more for the generator. Perhaps an old bike inner tube for the drive belt. The stand for the tank out of old pallets and the tank is an old bladderless pressure tank from a house that just moved to municipal water.

            The driving force behind this is cheap or free.

    1. There quite a few pump options, driven by windmills. Been several pumps featured on HAD, made from scraps. I’ve got one, that is simply a 12v motor that turns a long loose spring in a piece of tubing. It’s for draining engine oil from the filler cap. Never used it for that, but it work with water. You could probably pump water, and still generate some electricity for other things

      There were windmills pumping water, long before electric pumps, worth researching a little. Me, it’s been a wet year, plenty of rainfall, fortunately no Hurricane this season.

      1. We have had rain too, but it does not rain in the greenhouse. I have pondered putting gutters on it to catch what comes off of it. I even have some gutter to do that but they would block some sun… The thing with the turbine is you don’t get a lot of speed out of it so any kind of centrifugal pump is probably not going to work. You still have options but they get more complicated, even more so when you need both lift and the windmill located away from the water source.

  4. Just to mention here that ancient VAWT designs often used sailcloth instead of solid material to “catch” the wind. In this way, large designs with little material expense are possible. Sailcloth can be framed with sticks to form “pyramidal” shape pointing into the wind, for example.

    In other words, looking from above: v*^

  5. I love seeing these smaller projects, but like solar they dont scale well and doing whole home power generation in a DIY manner is very hard to find appropriate detail without being flooded by bogus backlink articles, chinease nonsense, and tons of warehouses offering the same product with no detail.

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