Micro Wind Turbine For Hikers

[Nils Ferber] is a product designer from Germany. His portfolio includes everything from kitchen appliances to backpacks. One project, though, has generated a bit of attention. It’s a micro wind turbine aimed at long distance hikers.

Even on the trail, electronics have become a necessity. From GPS units to satellite phones, to ebook readers. Carrying extra batteries means more pack weight, so many hikers utilize solar panels. The problem is that when the sun is up, hikers are on the move – not very conducive to deploying a solar array. The Wind, however, blows all through the night.

[Nils] used carbon fiber tube, ripstop nylon, and techniques more often found in kite building to create his device. The turbine starts as a small cylindrical pack. Deploying it takes only a few minutes of opening panels and rigging guy wires. Once deployed, the turbine is ready to go.

While this is just a prototype, [Nils] claims it generates 5 Watts at a wind speed of 18 km/h, which can be used to charge internal batteries, or sent directly to any USB device. That seems a bit low for such a stiff wind, but again, this is just a prototype. Could you do better? Tell us in the comments! If you’re looking for a DIY wind generator on a slightly larger scale, you could just build one from bike parts.

77 thoughts on “Micro Wind Turbine For Hikers

  1. Speaking as someone who has make a few ten day long trips in space amd weight constrained modes (backpacking, motorcycle camping, and canoeing) I can tell you that the device’s weight and packed size are going to be much bigger concerns to its end users than either efficiency or absolute power output and presumably the designer was working within these constraints…

      1. Well, space is all around us right? We all travel in space all of the time, even when we’re perfectly still because the earth,solar system, and galaxy are moving through space. So, we’re all astronauts, we just have a really big spaceship with all of our needs on board called earth.

        We’re all time travelers as well. the problem is we can only go one direction and speed.

        1. Nobody wants to think how much this resembles one of those SF tales about a generational spaceship where the culture has degraded and nobody remembers how to fly the ship, or even how to get to the bridge. And anyone who dares talk about how the ancient aliens left a hieroglyphic instruction manual in the Nazca desert is derided as a loonie, when we should be coming together to interpret those instructions and learn how to find the control center in the Tibetan Himalayas and take control of our changing climate!

    1. The angle of it will affect the power output. Unless it’s aimed pretty close to directly at the sun the power output will be greatly reduced.

      Ovshinsky cells on the back, top and both sides of a backpack, with a system to shut off whichever one(s) are facing away from the most direct light, would provide some power, except when you’re walking toward the sun.

      The backpacks from Solid Grey would be ideal platforms to cover with Ovshinsky cells. https://solid-gray.com/ (If you watch “The 100”, that’s the backpack that was used to hold ALLIE’s chip maker.)

        1. Hmmm that break would be 30-60 mins during one lunch (the mornings and evenings are almost useless due to weak sunlight) whilst the wind could blow all night….and put away some good amount of Wh into your batteries.

      1. I did some back-of-the-envelope math a few years ago, to come up with a simple number: What’s the breakeven point, in terms of hours or days of sun, where a solar panel would produce more energy than the same weight of batteries?

        I came up with “about 3 days of full sun”, for reasonable values of panels and batteries I could get my hands on.

        It seems that a similar number for wind would be useful here. The article does say “long distance hikers”, so presumably they’re planning to be in the field for quite a while, but where’s the breakeven point for this device?

        1. Yeah, although that leaves out a key feature: You can over-use your devices and run out of battery power early and be SOL. A panel gives you the option to keep using your devices a small amount even if you’re stupid.

    2. no, there are even off the shelf systems favailable for peanuts, most also include storage, and even with the losses mentioned above you would probably have twice the power available at a tenth of the weight as compared to this turbine.

    3. There are many situations wind would beat out solar. The appalachian trail for instance has many nicknames. One of the more polite ones is “the green tunnel” because you spend the vast majority of the hike under thick, sunblocking canopy. Of course the winds where I live would eat that thing raw, and a couple of cups on a spinner would be a far more durable design.

  2. Not bad, the geometry isn’t exactly ideal for a Savonius rotor, but my biggest concern would be what sort of wind loads it can operate in before it is distorted and fails, either to rotate, or structurally.

  3. Really quite fond of the mode of deployment, and the internal batteries are a great call. Really neat overall concept, especially if power output can be improved upon without much increase in size or complexity. (High efficiency gearbox running into something along the lines of an outrunner brushless motor, but optimized for use as a generator, then rectified to DC?)
    Just spitballing :)

    1. To get reasonable efficiency, you don’t just need a rectifier, you need a proper maximum-power-point tracking switchmode converter. Electronics can be very small, light and cheap, so it wouldn’t add much to the side, weight or price of the device.

      I’d think a major source of inefficiency is that fact that this is a drag-based instead of a lift-based design. Also, I believe it might work better if there was some more space between the sails, near the center; the higher pressure in the concave part of one sail now bleeds into the opposite sail, reducing the net torque. The convex side of the sail must be clear on all sides, to allow the wind to flow around it.

      Although I am most definitely not an aerodynamics engineer, so I could be very wrong about this.

  4. His turbine is not doing badly at all 5 watts. The vertical axis solves some problems that the horizontal axis turbine would present, by tapping power from a stator coil, and not needing a vane.

    I estimate a 30 cm radius, and 60 cm effective height (triangles an all). A wind of 18 km/hour is 5 meters/second through that area, or about 1.1 kg of air at 5 meters/second. This is about 14 watts of kinetic energy available from the air.

    Maximum theoretical efficiency of a turbine conforms to Betz’s law, so no more than 16/27ths of that kinetic energy can be extracted, so that’s about 8 watts maximum possible power.

    Windy ridges in nylon tents make for restless nights.
    Fortunately, altitude and exhaustion are sophorics.

    1. unfortunately it is the scale that makes this useless, you can get 15w of portable solar cells that you can actually use while walking, with 15000mah of storage, for 50usd, it even has a smaller footprint and lower mass.

      this type of turbine can be useful if it could produce enough to cover a more complex power usage, something to power the intermittent but fairly high demand of tools could really help remote villages or people, all of that is mostly a mater of scale, which would instantly change the scope from something so portable you can hike with it.

      1. Sure solar cell or just bringing charged batteries is more practical. But then you did not design it yourself to cap off your product design studies.
        Yes it looks like a polished turd to me too…

      2. I’d guess that you have not tried such a backpack mounted solar setup or you would have known that they are A) almost never at the best angle to the sun, perhapps you can get one segment to do that but that would be typically just 3-7w with the rest of the segments hanging uselessly down, B) whilst walking and following the typically twisty trails with some shaddowing from trees you typically just get brief moments of actually having the sun directly behind you…. C) and if you actually want to do some real charging you need to place the panels at the good angle to the sun where it can get uninterrupted direct light so that would be for some 30-60 mins during lunch break….yep that is all unless it is a rest day…. But the wind, if there is any, blows or can blow all night….putting good charge into your batteries and gadgets whilst they are not being used. Ideal in that sense. Ofcourse put your panels to use if and when you can but practice and experience tell me they are often cited as the be all but let me assure you they are far from it.

  5. Agree the RPM it is capable of is not impressive. A helical airfoil type vertical wind turbine would run 5 times as fast at the same wind speed. Manufacturing would be more expensive, but in the video, performance looks marginal. You don’t want a gearbox, that adds cost, noise and broken in a week. Why USB power? This kind of trekking is outside cell tower coverage. I always carry along a VHF for emergencies. Being capable of snapping selfies with your phone really isn’t a requirement. A detachable power bank in the base, so you could place the generator in the wind and you tent out of the wind?

    1. They do make hybrid GSM/sattelite phones that are not much bigger then a smartphone, and given how compact they have to be, they charge with <12V as well…
      USB even if far from ideal, is a widely accepted charging solution, all kinds of gadgets have USB charging.
      Also, smartphones have had satellite navigation capability for some time now, that and being a handy computer makes them worthwhile to drag along.

    2. Surprisingly modern phones have their use even outside cell tower coverage. To play snake or check your position via GPS on the map.

      But as the product designer is German I bet he’s only hiking the Alps and you’ll have a hard time to find a mountain top without coverage. Valleys are a different thing.

      1. The energy content (joule/weight) of liquid fuels such as candle wax or kerosene is about 100 times as high as energy of a li-ion battery, plus you can use the heat for cooking or keeping warm.

        1. That makes sense only if you need the heat at the moment as the efficiency of a thermoelectric generator is in the low 1 figure percent range. Counting not only the weight of the fuel but the apparatus makes the energy to weight ratio even worse.

      2. Nah, there should be sticks and leaves everywhere. Well maybe not right up the top of Everest, but the chaps in the picture look like they could tear up some scrub to burn. Peltier stoves are small, and if you actually need heat, you’re getting the power for free. The fan they have means you get more heat too.

  6. How about a kinetic energy recovery system akin to a self winding watch, a pendulum mechanism or a piezo system? You generate electricity as you walk. It may add to your energy expenditure but probably an unnoticable amount. Of course, if you have to wait out bad weather in your tent you won’t be generating electricity.

  7. As an alternative to using it recharge electronics, how about an emergency beacon? You could make it with alternating color vanes, or reflective vanes, or use it power a laser mounted to the rotating mast.

  8. One of the best systems I have seen, is a generator driven by a weight, intended to give light and charge telephones in rural africa

    You just fill a bag with dirt/stones/whatever and hook it onto a rope that is winded around the shaft of a generator, then you let gravity do the work.

    Sure, you have to lift the bag of dirt, to reset whenever the weight hits the ground, but it is a slow and steady source of power, and the built in batterypack could give you a full night of power to the LED light, or a full charge of your phone

    1. If you’re going to expend the physical energy yourself (which may not be an attractive option when you’re tired after a day of hiking), you might as well crank the generator by hand, and charge a battery with that. The bag of dirt method makes sense when you don’t have batteries, and a small load, such as a low power LED light.

      1. If you’re going to expend the physical energy yourself it’s probably best to attach the generator to your rucksack, leg, or shoes so the generator is cranked by the act of hiking.

        1. Actually a hand cranked or hand operated generator of some sort might make the most sense anyway. We’ve all seen the hand cranked flashlights. A hand cranked transmitter or device to power your cell phone just long enough to make an emergency phone call would really be all you should need. it’s not like your going to be needing electricity all the time. If you want light all night long do what people have been doing for centuries, build a camp fire.

    2. Somebody, it might be HAD, did an analysis on that weight-driven thing. Basically it’s useless because there isn’t enough energy in dropping a KG or 2 down a metre or two. And the mechanics need to be strongly built to cope with the strain. So it’s expensive and might break a lot.

      For that scale, converting muscle -> electricity is better done with something like a spring-powered radio-torch.

  9. “The Wind, however, blows all through the night.”
    The sun dose now shine every hour of every day of the year. It dose not rain 24 hours a day, every day
    and wind dose not always blow all through the night.
    As you walk you put your weight on one foot then the other foot.
    So something on the soles of your shoes to convert the presser and release of presser on the shoes to electricity
    to power your device or charge a battery?
    (Unless your doing a space walk)

    1. Winner!
      Footsteps are the only thing on the trail that is present every single day in a predictable amount. Can’t count on sun or wind. Often not enough, then too much. Just right isn’t often.

      Suggest pneumatic or hydraulic filled cushion inserts for your boots, or a plunger piston strapped to the boot connected by tubing to a small generator in your pocket as you don’t want extra mass at the feet the legs have to swing back and forth.

      Last few years of hiking I used a small AM/FM/Weatheralert radio with solar and hand crank generator, but it is weight you still want to dump on the trail plus cellular still really iffy. Thought GPS would be a benefit but paper maps and compass still lighter and work perfect if you keep track of your position hourly. Stars too. Mud and water crossings still same pain as always, don’t go past your hips.


      Completely cured my electrical problems… and suggest to others…

      Used to ride dirt bikes in the wayback times… and back to it now. Hiking replaced with a CHEAP dual-sport “round-the-world” motorcycle for trails as well as freeway. It’s a giant dirt bike and big battery charger. Same gear packed, plus laptop and gps but maps and compass along as well for certainty. Passenger gets bored instead of tired and whining about the same. Butt hurts instead of feet/legs but small stops are great cure. Much more variety of sights. Range vastly improved, 6 gallon tank at 55mpg. Last summer Yosemite, Grand Canyon, Sedona, Devil’s Tower, Black Hills, Area 51… one trip. Saw a sign “Caution: Cougar Crossing”. Napped on side of Colorado highway near a road sign, read it when I got up. Said “Beware: Grizzly Area”. Still dispersed camping (do your planning!), still just as deep into nature. Mud and water crossings still same pain as always, don’t go past bottom of seat (snorkel under it). Desert freeway speed limit sign: 85. Meteor Crater.

      1. It sounds like a complete pain in the arse, the hoses would go wrong, and you’d probably break your ankles.

        Walking’s not really compatible with having bits of things attached to our joints. The whole thing’s a complex operation full of feedback, prediction, and probably biological PID calculating. It takes us long enough to learn how to do it, and then we forget completely and it goes to automatic. Learning to walk with bits of string tied to your ankles, or weird hydraulic clown-shoes, doesn’t sound practical.

        Similarly the energy-harvesting floors some genius occasionally proposes. They’re just not gonna work. It’ll turn out that people keep falling over. And piezos will generate just about nothing. If you really wanted to steal energy from walkers, stick treadmills in corridors, so people drag a belt with their feet as they’re walking. The belt drives a generator. Like an inverted version of what they have in airports.

        Or, y’know, a few grams of coal, same thing.

  10. Another problem with both solar and wind solution is where you’re hiking. Solar doesn’t work too well when you’re hiking through the woods, nor do wind based solutions.

    A whole quadrangle takes up about as much space as the sails of this turbine and dosen’t need recharging. In all but the most remote regions you can download or buy maps. If you’re up to learn a new skill you can use QGIS or other Geographic Information Systems software to make your own from the raw data publicly avaialable. People in the US can download Quads from the USGS or other agencies.

    It’s a cool project but honing your orienteering skills and power management greatly reduce reliance on electricity. Getting a purpose built GPS unit instead of using your power hungry phone & carrying lithium batteries should keep your toys running for the whole trek. If you’re on a trail you don’t need your GPS on all the time if that’s your only source for the map.

    Best of luck to [Nils] I hope his project succeeds even if I see other, less digital, solutions.

  11. Yeah free design tip, I’d add magnetic disconnects because the last thing you want to find is that in addition to the wind turbine being missing….. it took your phone with it. Other than that it looks to be shaping up quite nicely, tho I feel the target market is definitely a very specific subset of outdoor enthusiasts.

  12. This gadget is very cool. It looks like an umbrella. I just don’t like the guy ropes (i.e. trip hazard?).

    One thing many posters are overlooking is the OP’s comment about why this is better than a solar cell. YOU CAN USE IT AT NIGHT AND WITH HEAVY OVERCAST! Can’t do that with a solar cell. And this thing is very lightweight in comparison. However, the US military (and FBI) uses a wind-vane version from Arista Power Rochester NY. The FBI recently purchased a bunch of Arista’s mobile man-pack wind turbines for remote site field operations. It is called the Power Charger 300i, however, the FBI purchased more of the larger pole mounted WIndTamers. The US DoD purchased the 300i’s for grunts and ground-pounders to use on LRRP’s. Not sure it’s still being manufactured due to them filing Chapter 7 recently. My next post will show a DYI version.


    1. Here is a DIY version of the Arista Power Charger 300i:

      It’s possible to make your own DIY wind turbine blades out of PVC piping, moulded plastic, fiberglass or aluminium, however with the availability of cheap Chinese imported blades there’s really no need to waste your time. The manufactured blades are also produced at exactly the right weight and angle to maximize efficiency so it’s in your best interest to get either new blades or also check out eBay and craigslist in your local area for some second hand blades. You can get your hands on some new Windtura windmill blades for under $100 on Amazon.

  13. Wow, maybe not for hiking but consider for a moment another application.
    Satellite power, how fast do those satellites wizz over the earth? thousands of miles per hour! We have been so stupid to waste that energy, simple ancient windmill power for our freedom loving amazing satellites vs how many square inches you can cram on a folding solar panel.
    Wind power satellites, even better than nuculur powered satellites.

    1. Or maybe this part of your body that is available about every 3-4 hours and does not require sticking anything in your body except maybe some water. It will supply you with plenty electricity to recharge a lot of hiking/camping portable electronic gadgets. https://goo.gl/4OXMjn

      I really like the L.E.O. satellite windmills! Is that solar wind as there is no wind or even air in L.E.O.? Or maybe they could use something like I suggested above paragraph since they “wizz” so much… /sarc :)

  14. Great read!!! Love the hiking tale :) I gave ya a follow. I have a few hiking tales myself you might enjoy, would appreciate the follow back. But otherwise thanks for the tips and story :)

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