Introduction: Enjoy a Nice Cup of Kite Powered Tea
Use kite generated electricity to boil a kettle of water . Pour the water into a mug with a teabag. Drink the tea.
Step 1: Reasons for Doing This.
Kites can extract huge wind energy. (called AWE Airborne Wind Energy)
The challenge is reliably handling pretty yet powerful kites, whilst they safely generate cheap electricity.
Why a cup of tea?
Tea is nice to drink and very refreshing. It's sociable to enjoy a cup in company. But it does take energy to brew. For the sake of the worlds freshest cup of tea an extreme ecological solution is needed.
Now I'm not growing tea high up on a kite yet...just boiling the water so far.
At the age of 99 my granny was asked what the greatest innovation in her lifetime was. The electric kettle.
Oh and my mum challenged me to do this.
Step 2: Make the Kites
Tea making chat is over for now.
Reuse as many available kite-able parts as possible. This isn't reinventing the wheel yet.
I'm describing a spinning kite torque to ground generation solution for this ible... The book has many others, just not this one, nor any of my favourite massive gulping and swaying net of ganged kite designs, nor many others, or, or, or many from here
- The Spinning Kite
Sew a coned ring (red rip stop) over a loop of 4mm carbon rod. I used 3 x 2m lengths. Make sure the ends of the rods are capped and covered, tucked into the ring to avoid snagging....
Attach ring bridling tabs with knotted end tails around the ring on both diameters. Cascade the upwind end (wide face of cone) ring bridling toward an upwind ring which you can tie onto. (first black ring above) The cone shape is inflated looking into the wind when flown; Like a wind sock. Top back end (downwind) bridles to cascade to ...I used a sewing machine bobbin on the lift line.
Attach sewn off parafoil kites around the outer of the ring. I set them fairly flat to true wind and get a bit of twist in the tip by attaching it's tether slightly ahead of the rotation direction on the upwind ring.
Stiffen the leading edge of the parafoils with carbon rod sleeved in the leading (I used inside) edge. Tuck a length of carbon rod (I used 2mm but it was too flexy in gale force conditions.) into end caps and tightly into neat strong pockets. 1 at the tip, the other end into a pocket which could be extended into the ring... but which I kept on the kite with the pocket sewn attached to the ring. If the kite rod crosses the ring rod you risk snapping one or the other.
Another thicker carbon rod 4mm is in a pocket as a brace, (black stripe on red ring) from ahead of the kites on the ring to midway up the kite. Where the thick rod crosses the ring rod I have added extra stiffening for the ring rod.
- The Lift kite next page
Step 3: The Lifting Kite
I had the great privilege of being allowed to make a Peter Lynn single skin lift kite using his templates pre production.
Pete is extraordinarily generous to have done this and point out my poor sewing skills.
It takes a long time to be that lucky. So instead you should maybe just buy one.
I am going to suggest a modification of adding 2 light and loosely anchored stabilisation lines to the b lines of the first rib inside the edges. This isn't a show kite it's a working kite. Pete will point out the flaw that we now inherently don't track the wind due to multiple point anchoring. Implying this kite rig has to be manned by a competent kite handler. I hope you're ok with that. Get some flying practice in.
You'll see in the picture a 7 year old can steer and loop the kite in this configuration. The amazingly stable single line kite is now a highly agile 3 line kite. And nothing pulls like this kite. WARNING IT'S IMMENSELY POWERFUL.
The internal speed-of-sound of tensioned UHMWPE ropes can approach Mach30. Don't risk it snapping toward you.
The wee guy in the picture is only holding loose steering lines on a slack day... That's safe.
Your lift kite choice should have enough pull to easily lift all of the kite and power transfer components. Having lift to spare allows you to configure a balance of lift and torque from the spinner. Other ways to stabilise lift kites.
In this method, We are also going to use the extra tension of the lift line to help us transfer torque to ground. Yes torque not just pulling tension out for power take off... Too easy. You can do that with just this lifter and a buggy.
Step 4: Torque Transfer to Ground Generator
Use the bottom of the tight lift line as an axle. The spinning kite and ladder spin round on the lifting line.
Spinning kites and ladder rungs could hockle (over twist) onto the lift line if it is too slack compared to the torque.
The lift kite tether is joined to the spinning parts using a roller-blade thrust bearing and wheel.
This is a torque ladder design. You may alternately choose a linked rings ladder type.
Hollow carbon rod rungs are tied together at their tips and fixed over the tight line at equal lengths. The lines between the rod tips only allow the rods to twist 45deg around the line axis with respect to each other. When 1 end rod turns they all turn.
At the top and bottom of the torque ladder is a ring you can tie off on. From these rings tie off more line back toward the closest rung. This cone shape of rope helps keep the plane of your crank rotation perpendicular to the tether tension vector.
(That's assuming your bike can track the wind freely. (weathercock).. but this is basic. I'm just going to bung my bike on a post)
The torque ladder top end attaches where the ring is attached to the kites and cone kite. Joining 2 lift line lengths together here helped me to tie this modularly. The ladder on the bottom part is connected to the rest of the spinning lift line going through the cone kite.
On the bottom end / the upwind ring, thread the lift line through the long pipe in a cross you've welded. Attach the lower end of the ladder securely to this cross.
To attach the cross to the bike. The long pipe part goes through the hollow bottom bracket, whilst the bar bolts and ties onto the correct crank for the direction of your kite rotation. I drilled another wee hole in my crank arm close to the bottom bracket to tie off securely.
Q: What is the dynamic of this torque ladder? Can you equate it in terms of G/(Wm) Grammes per Watt meter (efficiency of an axle).. What are the angular alignment effects?, tension relationships necessary?, Is 45 deg the most efficient twist? rung length effects? etc... if you're after doing a PHD in something interesting or you can tell me how to find an answer. I'd love to know. Have been trying to find answers with grasshopper and kangaroo.
Step 5: Bike As Generator and Power Source
Testing the Falco Hxm2.0 hub motor on my old mountain bike makes me smile.
Tying a rope ladder driven by spinning kites to my bike crank ... so that it makes power... That just makes me giggle.
Whack a long bar the same diameter as your seat post deep into the ground with the top end leaning back about 30 deg from vertical into the wind. Put your bike upside down on this post. The bike should have a bit of clearance over the ground and you should be able to adjust your gears as necessary. Lowest gear first. Remove front wheel and pedals. Neatly tie off the bike to upwind, so that the bike is lengthways across the wind. Use anchoring to the front and back of the bike.
Make sure your bike anchoring can resist a whole shed load of lift.
Lay the "Daisy" spinning kite ring on the ground, downwind of the bike. Put a couple of pebbles on Daisy upwind surfaces to stop them lifting. Connect the torque ladder cross end to the crank. Make sure the lift line runs clearly through the Daisy and into the roller blade wheel bearing. Tie the lift kite tether to the roller blade wheel..
Put the forward strut braces in their long pockets and then into the wee driver kite pockets. sew them closed. The two pockets should have a line tied between them to stop kites falling behind.
Check the wind again. Be sure of your anchors ... Maybe put some more in. Put 1 in where the lift bearing is just now and test the lift kite independently. Anchor lightweight loosely set steer guide lines downwind and to the sides of the lift kite. (these saved my whole lift rig last time I was out. If you can control the lifter happily, connect the spinning lift line top end bearing and lift kite tether. Release to the wind. You can do this slowly and restrict the rise with the test anchor you just used and a line down to it.
How's it spinning? Good.
Turn on the motor at the battery. Open the falco app if you have an ANT+ phone and link to the motor. This allows you to monitor speed, set the regeneration resistance levels and keep track of how much you have generated. (Alternate use the falco handlebar mounted controller, it won't show how much you generate though.)
In low winds be very wary of overloading the ladder. Too much torque demanded from the motor and gearing will stall the bottom end whilst the kite keeps spinning.... NOT GOOD! You'll have to stop the kite spinning and unwind a tangle. (ring to ring ladder systems will avoid the nastier ladder type tangles.) These hassles could also be avoided with an axial force actuated clutch or a software patch in the app... They'll all come in time. For now keep in a low gear and go gingerly on the regeneration.
Keep an eye on how much you have generated 30 Watt hours = a good big cup of tea worth of regeneration.
You need 2 way 280 metri pack connectors (Raffenday) to connect kettles to the battery. I used 2 DC kettles in series. It's about 39V in the battery. A 3 Ohm for a 24v battery (200w rated) and a 1 Ohm kettle for a 12v car plug did the job as expected (big one boils faster).
Now then as for which tea bag you should be using, that's a discussion...................................
If you're too lazy or tired to choose your teabag, just use the electricity to motor your way home again.
Step 6: Extend the Project
I've taken it to the next level... only in the literal sense... I've added another ring level onto my Daisy.
Now that it's shown to be modularly scalable... it's time to take it to the next level.
Somebody organise funding this research for me please.