Kite Power or “Airborne Wind Energy” is a young field of science and engineering. We develop fast flying kites to harvest energy from faster winds at higher altitudes. This uses less material to make more power. Networked kite power is the logical next step.
Why kite power? #1 scaling
The idea of using kites for wind power has compelling advantages. Primarily, kites work in tension, so they can be huge and lightweight. Traditional wind turbines contend with bending and compressive forces. Compare a modern suspension (tension) bridge with an old arch bridge (compression and bending). An arch bridge quickly becomes too heavy to build at scale. The lightweight tensile structure allows kites to scale, and therefore to work through large volumes of wind at high altitude.
We all know the problem with kites. Kites are hard to control. They fall from the sky. They love getting tangled in trees or if you’re really unlucky power lines or air traffic. That’s a problem.
Where kite power started
The control problems dominated early Airborne Wind Energy Systems (AWES) research. TU Delft, Freiburg, AWESCO and others conducted brilliant, primary research on kite power. Control was the essential primary focus because the designs being considered used a single kite wing on a long line. Standard kite designs were thought to be the fastest and most powerful. But they have serious drawbacks and compromises.
The Kite Networking Alternative
Alternative kite-tethering network designs have now demonstrated critical advantages in control, power density, reliability, safety, efficiency, scalability and more.
Networked kite designs exploit wide tether mesh patterns. A kite set on a network node, is fixed in position like a fly stuck in a spider web.
This lucky “spider” had a bumper day and caught a whole swarm of “midges.”
Stable lifting and Steady output
Despite hugely turbulent winds making individual kites pull hard in random directions, kites linked in a network hold position well, even without a control system.
Unsurprisingly, this design was not popularly investigated for AWES. This stable network of lifting kites is the opposite of fast moving.
This is where another kite network design comes in. A fast spinning autogyro kite turbine network called “Daisy”.
Kite power research usually exploits line pulling and retraction (yo-yo) or a kite lifting a wind turbine to send electricity down the tether (drag mode) But Daisy auto-gyro kite networks transmit continuous torque power to
This design relies on there being enough tension in separated kite lines to allow torque transmission. With more tension, more torque can be transmitted more efficiently. More kite layers on the network
Daisy – a tilted, hollow-axis, stacked, autogyro kite-turbine network. Catchy description.
Networks – Safe despite damage
Networks are amazingly resilient to damage. In the last test (see videos) a single layer, rigid kite ring, with <2kg flying material, output >1.4kW before a problem developed. There was no line tension sensor on the generator control. At high torque, high speed and low line tension, the lines over twisted and eventually broke through. Despite 7 lines breaking, because the network had a back-stop line, nothing broke away from safe anchoring.
Efficient and scalable by design
Daisy kites exploit the amazing scalability, (from speed,
Tensile network design allows the power of this architecture to scale. By combining the two network types. The Daisy (rotary networks) benefit from steady lift provided by the lifting kite networks.
Kites are lightweight, so they are easy to transport and because the force is in line with the material, they do not need a foundation, just an anchor. Windswept and interesting Ltd have tested transportable kite networks, which can be taken camping and be used to charge an EV car battery.
With Daisy kite networks, kite layers can be added starting close to the ground and going all the way up the stack. The kite layers help to expand the “shaft stack” which keeps powerful torque transmission viable.
Analysis of the design scalability by Oliver Tulloch (University of Strathclyde) and Roderick Read (Windswept and Interesting Ltd) is starting to reveal how vast volumes of wind energy can be harvested in an incredibly clean, cheap and safe way.
Look forward to hearing more about kite farm networks soon.
Windswept and Interesting Ltd
Rigid wing array kite turbines have huge advantages in energy generation.
Power to weight scaling has always been the core problem in Airborne Wind Energy. Kite turbine designs are the key to scaling airborne power systems whilst keeping them lightweight.
These designs exploit classic kite and AWES rules of thumb.
- Rigid Blades systems are more efficient than
- Multi-blade systems are even more efficient
- Small Rigid Blades tolerate extreme loading with
- Small wings are much cheaper per output
- Flying as fast as possible through as much air as possible in the power zone is where the power comes from
- Net arrays use less line / kite area = less line drag
MaximiseLift / Drag ratio for best results
- Smaller wings can operate in a wider wind range
- There is no single point failure so nets are safer
- Modular elements are easily swapped out to lower O&M cost
- Modular elements allow net deployments suited to current weather
- Networked kites are passively stable. This lowers control needs
- Wide tethering makes for dynamically stable kite positions
- Torque is the only way to obtain continuous power
- Hundreds of kites use a line more efficiently the one kite
- Avoid running lines to avoid worn lines
- Specialist lifting kites can support other specialist kites
We’re not just using rules of thumb, were proving new ground too.
- Kites can output torque. This was previously thought impossible.
- An AWES can operate without a control. Also thought impossible.
- Deformations in the ring structure observed in testing proved the theory that kite networks will expand dynamically in rotary flight. This simple fact will enable the testing of huge rotor diameters using
- Whole net turbine systems can be powered to rotate from the ground station to maintain tension and lift.
- Whole net turbine systems can be stalled in
mid airwith braking on the ground station.
- Whole AWES systems can easily be packed, carried and even taken on passenger aircraft as baggage.
Over the summer, Ollie and I got a lot of testing done. Ollie’s
Windswept and Interesting is looking forward to seeing how rigid blade expandable nets progress.
W&I are all about Portable Wind Power.
The Daisy Kite Turbine is an amazing ecological energy sourcing solution.
You can use it as the power source for an off-grid electric vehicle.
At only 30kg CO2 emissions equivalent in production, the complete prototype has a predicted carbon cost of energy of only 17g CO2/kWh in year 1 (already better than solar over its lifespan) and only 1.7g CO2/kWh with consideration of replacement components thereafter. YES 62x less CO2/kWh than diesel in year 1 and 620X less thereafter.
Daisy is a stunning Airborne Wind Energy System and only improving.
Our new controller is working incredibly well, giving smooth output and plenty of detail from the testing.
The car charge challenge would have completed by now had our inverter not blown up… (The supposed easy bit of this challenge, a pre-made, already solved technology… failed) Oh well
Here’s a copy of the latest plan. Stay excited!
Travel without polluting
Windswept and Interesting Ltd (W&I) make powerful and portable, flying wind turbines.
Any electric vehicle can carry our portable wind turbine for clean energy.
Electric vehicles can now travel far off grid, sourcing their own energy, without polluting.
The science of flying wind turbines
AWES harvest wind energy at high altitudes where the wind is stronger and more reliable.
Flying wind turbines capture more wind energy, with less material.
There are over 80 AWES companies, including Google X Makani, Shell KPS, TU Delft and Ampyx Power.
The energy from powerful, lightweight kite turbines has a tiny carbon footprint.
Kites working in a team
Networked kites are the Safest, Most Efficient and Most Scalable AWES designs.
The W&I networked kite turbine “Daisy” is the Easiest AWES to make and fly.
Daisy (a multi stage, tilted hollow axis, autogyro, network kite turbine) is very stable in flight.
Daisy is the only continuous & autonomous mechanical power AWES.
The Daisy kite turbine packs away to 1/7500th of its flying volume.
Many network kite parameters (# of kites, # stacks, solidity…) can be modularly reconfigured in the field.
Using only toy kites the Daisy prototype produced an incredible 300W/kg power density.
Kite Turbines, Kite Networks and Airborne Wind Energy.
Daisy Kite Turbines are going to have scientific recognition. The new AWES book is being sent for publication with Springer. Our chapter on Open Source Airborne Wind Energy Systems and the advantages of Networks in AWES is finished. KiteNetworksWandI Many thanks to Roland for checking, clarifying, formatting and re-ordering. The chapter is the first scientific description of an autonomous AWES. And the first to describe the potential of daisy style kite turbines and kite networks for energy transfer and scalability.
The chapter has been a long time coming. Many revisions have been made over the last 2 years. It was clear at AWEC2017 that there is a trend toward multi and rotary kite concepts in AWES. For very good reasons too. Networks are the logical progression of kite AWES formations. Their safety, scalability, efficiency, portability and sheer ease of use make clear sense. The true formalisation of that statement will still take a long time but the logic of it is now truly being accepted.
Andy is moving back to the mainland. Andrew Reeve has been business manager and test organiser here at W&I. He’s enjoyed island life, the kitesurfing here is amazing. His welding has definitely improved. A total asset. He’s still part of W&I, we’ll be in touch regularly. His mastery of the kite turbine airborne wind energy business is now second to none.
We still need sponsorship support for the kite turbine car charge challenge. NOT LONG TO GO NOW. Sponsorship will allow us to build a safe electrical car charging system. We still need to safely convert our existing output through a suitably large inverter and “granny” charge cable. Housing the equipment to make it safe to use outdoor in the Hebridean winter will also help.
The car is an AMAZING start but there is still a lot more to sponsor before we can go – generators, charge control electronics, batteries, kites, carbon rods, sewing, lines, … keep it rolling!
The World’s most AMAZING FLYING WIND TURBINE is
on Tour This Summer.
See Daisy and other Networked Power Kites flying at
Singapore Kite Day 29 – 30 July
Off Grid Festival 10 – 13 Aug
Airborne Wind Energy Conference 5 – 6 Oct
Daisy and other networked power kite configurations will be flown at these and other events throughout summer 2017. Don’t miss your chance to see this historic kite in action.
Daisy Networks are the worlds most scalable Wind Energy Solution.
Daisy is the only kite power design with continuous power output.
Daisy Network designs were the first to prove tensile torsion transmission.
Networked Power Kites will demonstrate a variety of concept proofs live this summer.
Networked kites are the SAFEST,
and MOST EFFICIENT Airborne Wind Energy Systems.
They’re going to be BIG
Best of all, you’ll be shown how to make them.
See you there. Keep tuned for more!
Have you ever seen a more gorgeous AWES kite anchor, ground-based, power generator system in your life?
fair enough, I hadn’t either.
Massive Thank You to Gordon Diesels in Stornoway for their help with cutting, welding and humor readjustments 🙂 It’s brilliant. The tracking rotation is rock solid and sooo smooth.
Bent pipe or more modular next time though.
That Iron, Nylon and Duct Tape machine can talk to my phone about kites.
Big Thanks to All these people:
Angus Smith and George MacLeod of Aiginish for technical skills.
Thanks to Ali G BeSpoke Bicycle Repairs @ The HUB for amazing Bike services.
Thanks to Kenny MacArthur for Yard and Shed space.
Thanks to SRM
Other Coves and Blones
Wahooo we raised a massive £4600 for open kite power research hardware….
Who even knows what that is?
You brilliant folks know it. You know it has amazing potential to clean up our energy environment relationship.
Thank You X X
Come visit any time, we’ll get some tea & then go sew and fly kites… This kite is going to be amazing.
Hebridean engineer uses kite science to develop affordable and scalable wind power system
Need to charge your batteries when you’re off-grid? Go fly a kite!
Many of us dream of travelling into the wilderness, far from the reach of modern life, but the reality is that these days fully charged batteries and reliable communications are an integral part of that escape plan.
While a mini solar panel might be enough to keep your mobile phone topped up, how could you ever keep your electric car fully charged while off-grid? Impossible. Or is it?
Rod Read, an inventor from the Isle of Lewis in Scotland, has taken on the challenge and is convinced it can be done. The trick is, he uses a network of kites as a wind turbine.
After successfully testing a solution to power his electric bike, Rod openly published working plans for it.
Rod now plans to scale his technology to the electric car level. “The bicycle challenge was easy enough,” explains Rod. “I cycled my e-bike and carried everything I needed to generate power while camping.” Rod used the kite to turn his regenerative e-bike motor to charge the bike battery.
Rods’ simple and affordable turbine uses spinning kites to turn a ground-based generator. Working in an open source hardware environment, in conjunction with the University of Strathclyde and TU Delft in the Netherlands, Rod has spent the last five years perfecting his design and his company is now selling these portable kite power systems online.
If you can fly a kite, you can now also generate sustainable energy.
So you’ve got remote power. What about communications? “Altitude really improves line of sight communications” says Rod. “With my phone secured safely inside a kite on the remote west side of the island, I can pick up 3G signal from the east side. Then I log into my phone’s wi-fi hotspot and I’m online!”
The self-sustained, internet connected, e-car camping trip will soon be a reality.
More information, including explanatory videos and sales can be found at – http://windswept-and-interesting.co.uk
Contact Rod: firstname.lastname@example.org +44 1851 870878
Thank You Forever
Windswept and Interesting owes a debt of gratitude to the following people. You all helped, donated, advised, inspired, supported, supplied, pushed, pulled.
You've Been There! The project has done amazing things already and it's going so much further thanks to you.
THANK YOU ALL !!!
Gordon Old, Patrick Sherlock, Andrew Brightwell, Phil Owen, Iain Dobson, Baptiste Labat, Ferg and Alison, Kenny Morrison, Jane Mac, Sandy MacDonald, Night_cavalerie, Hazel Macleay, Jude Maxwell, Amrita Ahluwalia, Ben Sandeen, Alice & Patrick Read, Jude Watmough, The Tullochs, KB, My family, My kids and their pals, Local engineering shops like Ivor Murray and Gordon Diesels have been brilliant, All the AWES tech geeks openly discussing online, Eddie Weather, Local sailors and fisherdudes, Especially the Smith family, AWEC, AWEIA, ALI G, Roy D, UHI, Strathclyde Uni, TU Delft, Freiburg Uni, NASA, FAA, Leodsaich, All the windsurf, kite & nutter surf mates I "grew up" with and the elements... Thanks x