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Energy Independence While Travelling

Bring your own clean power.
Pack a Kite Turbine in your EV

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Build a flying wind turbine for energy independent adventures.

Let's add portable kite power to your e-bike or e-car.
Harvest clean power on your adventure.

Kite Turbine - Basics.
Wind lifts, inflates and spins a network of kites for energy output.

Kite Turbine - How / Why?
Tensile structures are lightweight (materials align with forces)
The lightweight blades sweep a large area as an auto-gyro wind turbine.
Kites and rotors can stack and pack in modular network patterns for scaling.
Light and fast = efficient harvesting

Investigation into this method is ongoing and intended to addresses the carbon intensity of large wind turbines at scale.

WARNING ! Experimental prototypes!!
Consider Safety.
Carelessness kills!! Kites are powerful!!

We are automating for safety. Our new 10kW system will remove the need for a human operator.
Do not build a simple Kite Turbine larger than the >1kW capable one we show

Planet-Friendly Power
CC-BY-SA-4.0

How to make an energy independent electric vehicle with a Kite Turbine.

Instructions

  1. Put a Kite Turbine in your car
  2. Park up (best on a windy hill)
  3. Fly the Kite Turbine
  4. Use it to charge the EV battery

Well sort of, yes. 

We've flown a bunch of missions and made lots of power, done some car charging and made lots of tea in the field. Lovely.  But as you'd expect with wind power, and especially with freaky flying wind power, it's a lot more complicated than that.

I started testing ideas on kite power in 2010, because kites can provide a lot of power with little material. 

Harnessing kite power and converting it to electrical energy - can't be too hard ! And it's a really good thing to achieve because it could be scalable.

Most Airborne Wind Energy Engineers start out like this, and also from being Kite Surfers.

After a lot of experimenting, My favourite method is the Kite Turbine.

It's simple, continuous rotary output, scalable yet workable on a small scale, mechanically autonomous (apart from launch & Land & as long as it's all balanced)

You can see the launching process sped up in this video

First of all the lifting kite is launched. It's job is to guide the turbine downwind, and give initial line tension to hoist the turbine. 

The turbine is then released into the air using the back-line to hold it down.

The brake is released on the ground station so that rotation can start and regen can begin.

The wise among you might now be thinking... That's bizarre - torque - sent along a string  - but surely it would just twist?

And yes - without the kite line tension and the extra rings between the lines- it would twist and has twisted. The power transmission here is rotary, yes- that's novel, but it works. We use normal Dyneema(R) rope tethers. 

But How? This is where researching Tensile Rotary Power Transmission (TRPT) will help.

I'd recommend Oliver Tulloch's PhD and the Airborne Wind Energy Forum

TRPT works with 2 ratios, the geometry ratio (ring separation / ring diameter)  and the force ratio (Axial tension / torque) . For a given geometry ratio you can safely apply a certain force ratio by adjusting the torque demand at the generator. Balance these and it works.  More pull axially means a more torsionally rigid shaft = higher energy transfer capacity.

Now we have that tensile shaft power down on the ground we can plug it into a Power Take Off Wheel on an anchored ground generation station.

Notice that there are 2 sticks at the back of this ground station generator... Without them it get's wobbly.

This was a ground station and turbine combo I was preparing for the scouts (More about that at the bottom of this chat.

The ground station has to have a really good anchor. You never want to see a 20kg lump of edgy steel flung past your head by an angry kite.

For ground station designs go here ground stations

The ground station motor/generator controller code can be found here DaisyKiteTurbineControl

it controls this rats nest

A lot more on making and operating Ground Stations in this video

With the software and knobs and sensors, You can govern the max regen and mix the levels of control from the tip speed ratio, the tension torque ratio and the speed trend. You can also hold a brake and boost forward for start up or unwinding a mistake.

OK, nearly there.

Make sure your sram crank power meter (converted to the chainring sprocket) is connected to the wee bike computer.

Get a few powerful 36V e-bike batteries and connect 2 of them with XT-90-s anti spark plugs to the power in leads. Connect the Mega 2560 (way too slow for next revision) to your pc to get a stream of data.

Run the turbine to charge the batteries... just like that.

With your spare batteries, Connect them very carefully to a ~5kW inverter. Very Carefully.

Then fish out an EVSE car charger capable...

Read more »

sub 1kW Kite Turbine Parts Descriptions.pdf

The bits you need to put together and what they do

Adobe Portable Document Format - 779.25 kB - 05/02/2022 at 10:29

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  • 1 × VESC6 The VESC (Vedder Electronic Speed Controller) will save you grief. It's an amazing motor controller. pricey though.
  • 1 × E Bike Wheel If you get a direct drive motor with a wheel and rim for the PTO that's easiest. If you get a gearedhub motor you have to make sure you are running the motor the right way and the wiring is coming out the correct side or you can weld the clutch on the planetary gear ... see my youtube on that
  • 1 × e-bike motor cable standard connector often Julet Keep your cabling tidy and connectors dry
  • 12 × 2m x 5mm GRP or Carbon epoxy rod lengths to make the torque tube and top support rings You will need varying lengths of this for different rings ~12 x 2m
  • 1 × Dacron Tape for leading edges, line tapers, webbing, seams, joins, ring cuffs, anything sew-y

View all 25 components

  • Sims

    Roddy "Rags" Read06/03/2022 at 08:46 0 comments

    Got a couple of sims for you

    A view of our long term ambition - a network of networks, Kite Turbine field layout 

    Rough animation of a Backline handling Bot to improve ease of deployment and safety

    Using a Backline Bot will likely be our standard method for single turbine releases on flat enough ground till maybe 100 ~200 kW

    After that  - inside the net of nets (as above) deployment from the ground station will be better...

    Might look like this

    For a tilting carousel like this which releases the rotors and transmission lines and rings - We'll want the rotors to be able to expand in tension once spinning.

  • Your Motivation - Why Kite Turbines Matter

    Roddy "Rags" Read04/28/2022 at 20:58 0 comments

    This is why - We all want a future with Abundant Clean Energy 

    Kite Turbine power is scalable using lightweight tensile networks.

    Higher altitude wind is more energy dense and these kite turbines are very light in embodied CO2e   So if we can make these turbines reliable (already mechanically autonomous)   They could change the game on cheap and clean energy farming. 

    So

    How to make an energy independent electric vehicle with a Kite Turbine.

    More Detailed Instructions

    1. Make a Lifting Kite
    2. Make a Kite Turbine
    3. Make a Ground Station 
    4. Put it all in your car
    5. Park up (best on a windy hill)
    6. Fly the Kite Turbine
    7. Use it to charge the EV battery

    First though We're going to talk about your motivation (Is that something actors do?)

    Motivation Instructions

    Build a Kite Turbine

    Simple as that. It's fun, It's got power comes out. Not only that ... You might be doing a really good thing.

    We build Kite Turbines because the world needs clean affordable energy.

    We all know wind turbines are amazing right.

    Yes - but no. They're so heavy they can't scale. 

    Wind power is not yet as amazing as it's going to become.

    Looking down on wind turbines from an airplane, you realise, they are tiny compared to the airspace they could be extracting from, and that airspace has more powerful and consistent wind away from the surface.

    A Network of kites high above a wind turbine farm
    A Network of kites high above a wind turbine farm

    Here's why Wind turbines aren't as high as kites yet.  They're seriously heavy. See this IRENA graphic. 

    Wind turbine towers are massive rigid steel structures. Strong enough to resist the cantilever bending, head mass loading and generation torque. These towers have to follow cubic mass scaling (To the power of ~2.63) 

    Onshore, the tower is fixed to a huge concrete foundation to prevent it toppling over. 

    A road has to be built up a hill. Giant blades have to be made so that the tips (the efficient part) can sweep further at high speed.

    This is not an efficient design yet. Material is not aligned with the force. 

    Like a suspension bridge, Kite Turbines use efficient design to align the loads (blade aerodynamic forces) with efficient tensioned lines.

    Kite Turbines don't need the tower, the foundation, or the road.

    Even most of the blade is cut from a Kite Turbine. These blades only fly the outermost ring. The most efficient part.

    Generic Kite Turbine design
    Generic 3 layer x 5 blade rotors Kite Turbine design, Let's say ~ 10kW

    The power to weight ratio of standard wind turbines is dreadful, which means it takes them longer to pay back the carbon equivalent emissions embodied in their manufacture.  Endurance E3120 50kW = power-to-weight ratio of only 0.02kW/kg (And that's a good one it's only wee)

    Kite Turbines Power-to-Weight tested 1kW/kg (Airborne) 0.2kW/kg (total)

    You've seen how basic our Kite Turbines were... We are quite certain we can increase this to >2kW/kg (airborne)  >.8kW/kg (total)

    When I walk up to a wind farm, Standing right up underneath a giant wind turbine, I look at the stairs leading to the tower access door. I estimate the mass of just the handrail (not the balusters) is the same mass as an entire >3kW Kite Turbine. 

    That 3kW is a magic number... Your modern kettle is up to 3kW.  3kW is ~ the average (24/7) power demand of a UK home. It's also the speed your domestic plug will charge an EV car. And this Kite turbine fits in the back of your car ... oh

    Here's the thing, this could be BIG

    We suspect kite turbines are going to be very scalable

    Eventually with more research - The forces in a network of network turbines should look something like this

    And we're going to assess how offshore capable they are.

    There are further positive effects of designing wind turbines (Kite Turbines) this way. The modular blade elements can all be swapped out very quickly on the ground (no crane or rope access experts needed) ...

    Read more »

View all 2 project logs

  • 1
    Read up

    First off, before building, make sure you have a good clear understanding of what you want to build.

    The scale and complexity of a kite turbine project is a large undertaking for a home project.

    Check the files section and read the  - sub 1kW Kite Turbine Parts Description document to get a clearer idea of what you could build.

    I don't recommend going straight to the scale of 1kW - That in itself can be a dangerously powerful kite machine.

    Please feel free to adapt this. However- 

    This project is CC-BY-SA-4.0 as long as you keep it under 1kW.

    None of this work is for Kite Turbines in excess of 1kW 

    We will be attempting automated control of larger Kite turbines at W&I only when we remove all human operations from the field of work. 

    Thank You for reading that warning list so carefully

  • 2
    Lift kite

    Let's start at the top with the lift kite

    An HQ KAP foil lift kite is a good steady lifter ... not so strong pulling as a single skin but stable.

    Make sure it is pulling >10kg on the line before you attach it to the top of the turbine.

    Here's how they handle in extreme turbulence with a variety of bridle, tether and tail modifications

    Making a controller for these lift kites is easy enough with radio control and a servo pulling the B2 steering lines  ... This will allow you to pull the turbine to the side and stall it without using a backline.

    Adding an arduino and an IMU is bonus - Some simple proportional code https://github.com/rodread/lift-kite-controller

    Here's a description of how that went on the AWES forum

    https://forum.awesystems.info/t/building-a-rc-pilot-kite/524/18

    Some old Daisy Kite turbine launching videos

  • 3
    Making Kite Turbines 2 different ways

    Now for the turbine

    First up is the older Ram Air Kite Turbine Way

    I published the detail for that on Hackaday a few years back https://hackaday.io/project/159049-portable-kite-turbines/log/149130-oh-yeah-the-kites   Gave that hack a big update yesterday

    This is how the turbine for the scouts went together

    Right now for the 2nd version using rigid blades  

    ...  This makes a much faster and more efficient turbine

    A single rotor element now looks ~like this

    DaisyUnit.jpg

    A NACA4412 foil cut from foam, built like a model airplane wing, at 20cm cord ~1m span. Covered in shrink film.   2x 170cm carbon rods go in the main ring compression cuff (forward of the wing) 4 bridles hold the blade to the main tether. Bridles bank the blade with outer tip slightly pointed down (This directs lift away from the axis and helps rotor expansion against torsion.. Helps for stacking rotors.)

    An stl of the fuselage is in the github links https://github.com/rodread/DaisyKiteTurbineControl (often appears 10x too small on 3d print slicing software - comes from rhino working in mm not cm) 

    The blades are hot wire cut foam, with shrink bonded tape covering. Then plugged into the fuselage cuffs. Then duct taped to the cuffs. 

    The shrink wrapped blades are slotted into the fuselage cuffs.

    The spars tubes run through inside the blades and through the fuselage the whole length of the span. The bridles tie around the spars.

    A line looped through both of the spar tubes holds them into the foam, preventing them from being flung out by centrifuge. (That has happened. Do avoid throwing spears around your field)

    Daisy Unit Topside.jpg

    There's 4 wee spreaders (made from ~2cm lengths of rod) to stop the bridle cutting into the wing and spars.

    Here is a dimensioning guide for Kite Turbines

    Super simple

    For our next set of wings I'm leaning toward ...a mix of cut/print wing rib with foam inserts, a printed fuselage as before, all slotting on together with carbon spars, tied through and end capped ... and also I think a vacuum carbon epoxy skin might work nicely. If you make wings... please get in touch.

    Also for getting more blade performance data to the generation control . I've re-worked the amazing D-Rhem VTOL flight controller to get rotational position dat from the rotors with an ESP32 and MPU9250 https://github.com/rodread/dRehmFlight/tree/master/Versions/dRehmKITE_rod_ESP_wifi-mpu9250SPI

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Roddy "Rags" Read wrote 06/03/2022 at 08:39 point

Another view of our long term ambition - a network of networks, Kite Turbine field layout 

https://youtu.be/LbzBQRRHago

  Are you sure? yes | no

Roddy "Rags" Read wrote 05/24/2022 at 11:41 point

Yay, We got through round 1 of the prize!!! Wooop Thanks!

Here's a simulation I made of the long term goal

https://youtu.be/5eUDLZy5hmw

  Are you sure? yes | no

Jacob wrote 05/03/2022 at 15:09 point

Very cool project!

  Are you sure? yes | no

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