kiteKRAFT – Clean & Economic Energy We make more affordable wind power plants,
based on a tethered electric aircraft – that’s a kite.
Want to get your kite power plant?
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1. The Challenge

1.1. Today's energy generation is dirty!

Energy is generated mostly from fossil or nuclear power plants today. This has a number of serious shortcomings: (1) Fossil fuel resources are limited, and therefore alternatives must take over – sooner or later. (2) The environmental impact of fossil fuels is rather large. (3) Nuclear energy carries great risks and produces nuclear waste.

1.2. Today's renewables are not cost effective enough and therefore not deployed fast enough.

Indeed, the situation is dramatic: Humankind has only a few decades left to reduce CO2 emissions down to zero, to achieve the "2 degrees Celsius target" and thus prevent the tipping of our planet's climate, see e.g. this news article by Spiegel or this talk by Harald Lesch. That is realistically only possible through improved renewable energy technologies and their massive expansion.

Our planet earth is the only place in the entire universe that we know of, where we humans can survive. Should we not handle it with much more care?

2. The Solution

1.3. Use only the most effective part of the wind turbine!

(1) Such a three-bladed upwind turbine is the most successful wind power plant design today.
– Scroll down to see, how we can improve it. –

(2) A blade's wing tip harvests the majority of the energy, because it sweeps the largest area and experiences the strongest airspeed.

(3) Most other parts are only support structures. – Those are replaced by a tether and a small ground station. The wing tip is now a kite.

(4) Small wind turbines on the kite generate power and the kite flies figure eights (≈ two connected circles) to avoid tether twisting.

A kite power plant has a number of advantages compared to conventional wind power plants:

  • 10 times less construction material is required.

    A kite power plant uses only the most effective parts to extract wind energy. This results in an overall small footprint.

  • Stronger winds in higher altitudes are accessible.

    The tether may be several hundred meters long and thus the kite may fly several hundred meters above ground.

  • The whole power plant can have a high mobility.

    The deployment site may be temporary and changed regularly.

  • Overhaul can be executed on the ground.

    For overhaul or maintenance, the kite is simply landed. Due to the high mobility, it is even possible to overhaul the power plant completely at dedicated facilities.

  • Low Visual Distraction.

    Since no tower or large wings are necessary and because the kite flies relatively high compared to its size, the power plant is hardly visible. Therefore, the impact of a kite power plant on the landscape is smaller than other power plant technologies.

  • Clean & Economic Energy.

    Kites can generate energy in the cleanest way: it is renewable energy and only little energy intensive material is required. Moreover, kites can generate energy in the most economic way due to the above mentioned advantages: 90 % of the construction material of a conventional wind turbine is virtually replaced by the software which controls the kite.

3. kiteKRAFT Technology

3.1. How it Works: Fully Autonomous Operation

...exemplified with our 20 kW kiteKRAFT system market entry product.

(1) Wait

The kite rests on the ground station during no wind, storm, or overhaul.

(2) Hover

The kite uses its rotors as propellers like a multicopter. It hovers downwind, until the tether reaches full length.

(3) Transit

The kite launches with full thrust into crosswind flight (figure eights).

(4) Generate

The kite flies crosswind in figure eights and generates power by using its rotors as wind turbines. Power is transmitted over conductors integrated in the tether.

(5) Land Again, If Necessary

If a landing is required (no wind, storm, overhaul), the process is reversed.

3.2. Competitive Advantages

The kiteKRAFT technology includes a number of innovations, which result in three key techno-economical advantages:

  • Extreme Reliability.

    With our patent pending technology, even a short circuit anywhere in the system – even in the tether – is no harm.

  • Ultra-High Power Density.

    A small “kite” already makes huge “KRAFT” (power) – kiteKRAFT! This is achieved by a biplane structure and a specialized airfoil.

  • Cost-Efficient Manufacturing.

    The kite power plant can be produced at low costs for both, small series production and mass production.

Besides that, we have two more strengths:

  • Strong Academic Background.

    One kiteKRAFT team member (see below) wrote his Ph.D. thesis about kite power (see below). Many airborne wind energy concepts were investigated with scientific neutrality and precision. The most promising concept is selected and optimized: The result is the kiteKRAFT technology.

  • High-Tech Made in Germany.

    kiteKRAFT systems are developed in Munich, with good access to infrastructure, academia, and qualified workforce.

4. Products

4.1. The 20 kW kiteKRAFT System

The 20 kW kiteKRAFT system is our first product and is currently under development. Rollout is scheduled for 2022. The picture shows the kite during hovering, shortly after launch or before landing. How the system operates was already shown above, here and here.

Technical Data

Nominal Values
Nominal Power: 20 kW
Cut-In Wind Speed: 6 m/s
First Power Point: 12 m/s
Second Power Point: 20 m/s
Cut-Out Wind Speed: 25 m/s
Ambient Temperature: -20 °C to +50 °C
Kite
Wing Span: 4 m
Wing Area: 1 m²
Weight: 30 kg
Rotor Diameter: 0.4 m
Number of Rotors: 8
Total Rotor Area: 1 m²
Tether
Length: 100 m to 150 m
Voltage: ± 400 V DC
Conductor: Copper
Strain Relief: Kevlar
Ground Station
Structure: 10 ft ISO Container
Weight: 5,000 kg
Installation Altitude ASL: 0 m to 2,000 m
Electrical Interface: AC 230 V/400 V, 50 Hz
or AC 120 V/210 V, 60 Hz
Battery: 20 kWh
Sensors: Wind Speed,
Wind Direction,
Atmospheric Electric Field
Control
Flight & Power Control: Fully Autonomous
Flight Pattern: Inside-Down Figure Eight
Flight Altitude AGL: 0 m to 80 m
User Interface: App & Web
Remote Servicing: Yes

Levelized Cost of Electricity:

as low as 0.25 EUR/kWh

All values are preliminary and are subject to change without notice.
Wind speed values refer to the reference altitude of 80 m AGL.
The tether length, ground station electrical connection and levelized cost of electricity depend on the deployment site.

Customer Advantages

The 20 kW kiteKRAFT system is designed for own consumption and island grids. A typical customer of a 20 kW kiteKRAFT system is a farmer, a company branch in a rural area, a surface mining company, an island grid system provider or -operator, an innovative utility company, an NGO or comparable, or a private enthusiast. If you decide for a kiteKRAFT system, you gain the following advantages compared to your alternatives (which may be your local electricity provider, a conventional wind turbine, a photovoltaic system, or a diesel generator):

  • Clean.

    You help to transform our economy towards 100 % sustainability. – Power generating kites are obviously cleaner than fossil energy technologies, but they are also cleaner than a conventional wind turbine and a photovoltaic system, because much less construction material is required, from which only little is energy intensive material.

  • Innovative Power Plant (≈ Tethered Electric Aircraft).

    With such a power plant you can visibly demonstrate to your own customers that you are innovative and support renewable energy technologies.

  • Independence & Energy Security.

    A kiteKRAFT system decreases your dependency on third parties such as utility companies or fossil fuel companies. You are less affected by their price increases. You can bridge a blackout with your kiteKRAFT system – even if the wind is not blowing due to the anyways installed batteries in the ground station.

  • Mobile, Fast, Flexible.

    If you need the kiteKRAFT system for some time at a certain site and later at another site, you can easily do that. This can be useful for farmers (crop rotation) or surface mining companies. The kiteKRAFT system may also be used just temporarily e.g. for disaster response by NGOs. Because of the mobility and because of the low footprint, the system can be transported, installed and uninstalled quickly and flexibly, even if there is no or only limited road infrastructure.

  • Simple Operation.

    The kiteKRAFT system works completely autonomously at all weather scenarios. If required, you can also command the kite to land just with the push of a button in a smartphone app. In particular, there is no need to think about any fuel, i.e. no ordering, transporting, storing and regular refueling of diesel is required.

  • Lower Electricity Costs.

    Depending on your deployment site and utilization, the kiteKRAFT system can generate electricity at lower costs compared to all alternatives. After the amortization time, electricity is even for free.

What about a kiteKRAFT system for your farm?

What about a kiteKRAFT system for your company?

What about a kiteKRAFT system for your surface mine?

What about a kiteKRAFT system for your remote community?

What about a kiteKRAFT system for your land house?

What about a kiteKRAFT system for ...?

You can imagine more applications? Please tell us!

Interested?

You have any questions? You have any requirements we should include into the product development? You have a test site we can use? You are interested in obtaining a 20 kW kiteKRAFT system?

We would love to here from you! Please leave us a message:

Reserve your kite power plant!

4.2. Towards Multi-Megawatt Systems

The 20 kW system is only the beginning. A main purpose of it is to fully demonstrate the technology and its economy.

To really contribute to the global energy transition, larger systems are required, which generate electricity at very low costs. The kiteKRAFT technology has an excellent scalability: Due to nonlinear aerodynamic effects, larger systems are more efficient and the levelized cost of electricity is the lowest compared to any other technology. A kite power plant can become the standard choice of power plant investors and utility companies. This also opens up global energy markets with a market volume of hundreds of billions of euros per year.

The 20 kW kite has a wing span of 4 meters.
– It will look tiny compared to the bigger kites planned. –

Kite with 4 meters wing span

With only 20 meters wing span, the nominal power is already up to 2 MW.
– Such kites reach grid parity, i.e. 0.05 EUR/kWh or below. –

Kite with 20 meters wing span

And with 40 meters wingspan, up to 10 MW are possible.
– The levelized cost of electricity is well below 0.05 EUR/kWh. Even larger kites are thinkable. –

Kite with 40 meters wing span

5. Research Publications

The innovations of the kiteKRAFT technology are a result of yearslong research conducted at the Technical University of Munich (TUM). Listed below are our publications, which present many of our research results. You can dig deeper into the science behind power generating kites and learn why our approach has so many advantages.

  1. Florian Bauer. “Multidisciplinary Optimization of Drag Power Kites”. Dissertation. Technical University of Munich. Planned publication in late 2018.
  2. Florian Bauer and Ralph M. Kennel. “Design Sensitivities of Drag Power Kites”. In: 8th Energy Colloquium of the Munich School of Engineering “Advances in Energy Transition”. Ed. by Thomas Hamacher. Garching-Hochbrück, Germany: Technical University of Munich, Munich School of Engineering, July 19, 2018, p. 108. doi: 10.14459/2018md1449240. url: http://www.mse.tum.de/veranstaltungen/mse-kolloquium/kolloquium-2018/. download: Abstract-PDF, Poster-PDF.
  3. Florian Bauer and Ralph M. Kennel. “Fault Tolerant Power Electronic System for Drag Power Kites”. In: Journal of Renewable Energy (Hindawi) 2018 (Apr. 16, 2018). doi: 10.1155/2018/1306750. url: https://www.hindawi.com/journals/jre/2018/1306750/. download: Preprint Paper-PDF, Full Paper-PDF.
  4. Florian Bauer, Ralph M. Kennel, Christoph M. Hackl, Filippo Campagnolo, Michael Patt, and Roland Schmehl. “Power Curve and Design Optimization of Drag Power Kites”. In: Book of Abstracts of the Airborne Wind Energy Conference 2017. Ed. by Moriz Diehl, Rachel Leuthold, and Roland Schmehl. Freiburg, Germany: Albert Ludwigs University of Freiburg and Delft University of Technology, 2017, pp. 72–73. isbn: 978-94-6186-846-6. doi: 10.4233/uuid:4c361ef1-d2d2-4d14-9868-16541f60edc7. url: https://repository.tudelft.nl/islandora/object/uuid:c40f14fc-b4ba-498a-84c4-f2b745b4417b. Conference video available from: http://www.awec2017.com. download: Slides-PDF.
  5. Florian Bauer, Ralph M. Kennel, Christoph M. Hackl, Filippo Campagnolo, Michael Patt, and Roland Schmehl. “Drag power kite with very high lift coefficient”. In: Renewable Energy (Elsevier) 118.Supplement C (2018), pp. 290–305. issn: 0960-1481. doi: 10.1016/j.renene.2017.10.073. url: http://www.sciencedirect.com/science/article/pii/S0960148117310285. download: Preprint-PDF.
  6. Florian Bauer, Christoph M. Hackl, Keyue Smedley, and Ralph M. Kennel. “Multicopter With Series Connected Propeller Drives”. In: IEEE Transactions on Control Systems Technology 26.2 (March 2018), pp. 563–574. issn: 1063-6536. doi: 10.1109/TCST.2017.2679071. url: http://ieeexplore.ieee.org/document/7888441/. download: Preprint-PDF.
  7. Florian Bauer, Christoph M. Hackl, Keyue Smedley, and Ralph M. Kennel. “‘Virtual’-power-hardware-in-the-loop simulations for crosswind kite power with ground generation”. In: 2016 American Control Conference (ACC). Boston, USA, 2016, pp. 4071–4076. doi: 10.1109/ACC.2016.7525561. url: http://ieeexplore.ieee.org/document/7525561/. download: Preprint-PDF.
  8. Florian Bauer. “Airborne Wind Energy – The Future of Wind Energy?” In: IDTechEx Show! Energy Harvesting & Storage. Santa Clara, USA, November 18–19, 2015. url: https://www.idtechex.com/events/presentations/airborne-wind-energy-the-future-of-wind-energy-007459.asp. download: Slides-PDF.
  9. Florian Bauer, Christoph M. Hackl, Keyue Smedley, and Ralph M. Kennel. “Crosswind Kite Power with Tower”. In: Airborne Wind Energy. Advances in Technology Development and Research. Ed. by Roland Schmehl. Green Energy and Technology. Springer, Singapore, 2018, pp. 441–462. isbn: 978-981-10-1946-3. doi: 10.1007/978-981-10-1947-0_18. url: https://link.springer.com/chapter/10.1007%2F978-981-10-1947-0_18.
    1. Florian Bauer, Christoph M. Hackl, Keyue Smedley, and Ralph M. Kennel. “On Multicopter-Based Launch and Retrieval Concepts for Lift Mode Operated Power Generating Kites”. In: Book of Abstracts of the International Airborne Wind Energy Conference 2015. Ed. by Roland Schmehl. Delft, The Netherlands: Delft University of Technology, 2015, p. 92–93. isbn: 978-94-6186-486-4. doi: 10.4233/uuid:7df59b79-2c6b-4e30-bd58-8454f493bb09. url: https://repository.tudelft.nl/islandora/object/uuid%3A378559a9-499e-49dd-a357-d7521a338254?collection=research. Conference video available from: http://www.awec2015.com/.
    2. Florian Bauer, Christoph M. Hackl, Keyue Smedley, and Ralph M. Kennel. “Multicopter-Based Launching and Landing of Lift Power Kites”. In: Airborne Wind Energy. Advances in Technology Development and Research. Ed. by Roland Schmehl. Green Energy and Technology. Springer, Singapore, 2018, pp. 463–489. isbn: 978-981-10-1946-3. doi: 10.1007/978-981-10-1947-0_19. url: https://link.springer.com/chapter/10.1007%2F978-981-10-1947-0_19.
    1. Korbinian Schechner, Florian Bauer, and Christoph M. Hackl. “DC-link Control for Airborne Wind Energy Systems During Pumping Mode”. In: Book of Abstracts of the International Airborne Wind Energy Conference 2015. Ed. by Roland Schmehl. Delft, The Netherlands: Delft University of Technology, 2015, p. 39. isbn: 978-94-6186-486-4. doi: 10.4233/uuid:7df59b79-2c6b-4e30-bd58-8454f493bb09. url: https://repository.tudelft.nl/islandora/object/uuid%3A114710f1-b5ba-4d03-88f5-c5db05f1583b?collection=research Conference video available from: http://www.awec2015.com/.
    2. Korbinian Schechner, Florian Bauer, and Christoph M. Hackl. “Nonlinear DC-link PI Control for Airborne Wind Energy Systems During Pumping Mode”. In: Airborne Wind Energy. Advances in Technology Development and Research. Ed. by Roland Schmehl. Green Energy and Technology. Springer, Singapore, 2018, pp. 241–276. isbn: 978-981-10-1946-3. doi: 10.1007/978-981-10-1947-0_11. url: https://link.springer.com/chapter/10.1007/978-981-10-1947-0_11.
  10. Florian Bauer. “QtPLC: A C++11 Qt PLC library for a Preempt-RT real time Linux based distributed control system for airborne wind energy”. Master thesis. Technical University of Munich. 2013. download: Document-PDF.

6. Team

We are a team of electrical, mechanical, and environmental engineers with a passion for technology and environmental protection. We are specialists in our fields of expertise as well as generalists. All competences required to develop kite power plants are covered by our team, partners, and advisors.

Photograph of Florian Bauer

Florian Bauer, M.Sc.

Florian is an electrical engineer and Ph.D. candidate at the Technical University of Munich (TUM), has 5+ years experience in kite power research, and is the inventor of the patent-pending kite powertrain. He is a co-founder of kiteKRAFT and is responsible for the systems engineering and the kite autopilot.

LinkedIn Profile | TUM Contact Webpage | TUM Research Webpage

Photograph of Christoph Drexler

Christoph Drexler, B.Sc.

Christoph is a mechanical engineer and M.Sc. candidate at the Technical University of Munich (TUM) with his master thesis on the “Design Optimization of Multi-Element Airfoils for Drag Power Kites”. He is a co-founder of kiteKRAFT and is responsible for the airframe and kite power plant mechanics.

LinkedIn Profile

Photograph of André Frirdich

André Frirdich, B.Sc.

André is a mechanical engineer and M.Sc. candidate at the Technical University of Munich (TUM), has a strong background in rotor aerodynamics, and is currently conducting his master thesis on the “Design Optimization of Rotors for Drag Power Kites”. He is a co-founder of kiteKRAFT and is responsible for the kite's rotor developments.

LinkedIn Profile

Photograph of Max Isensee

Max Isensee, B.Sc.

Max is an environmental engineer with a focus on sustainable energy and entrepreneurship, he co-founded the climate protection organization Protect Our Winters Germany, and worked as start-up consultant at Karlsruhe Institute of Technology (KIT). He is a co-founder of kiteKRAFT and is responsible for business development, (pilot) customer projects, and financials.

Photograph of Andreas Graf

Andreas Graf, M.Sc.

Andreas is an electrical engineer and has 4+ years experience in electronics and micro controller software at a major semiconductor manufacturer. He supports kiteKRAFT in the development of the kite power plant electronics hardware and software.

LinkedIn Profile

Photograph of Markus Schütz

Dr.-Ing. Markus Schütz

Markus is a mechanical engineer and has 8+ years experience in mechanical engineering, measurement equipment, and business development (he co-founded etersys GmbH). He supports kiteKRAFT in the development of the kite power plant mechanics and business development.

XING Profile

Partners & Advisors

Technical University of Munich (TUM) UnternehmerTUM Xpreneurs Climate-KIC Munich RE ERGO

kiteKRAFT has several advisors with background in entrepreneurship, management, aerospace, wind power, and other relevant fields of technology.

Become Part of the Story – Contact Us!

You are a business angel or VC and you can imagine investing in us? We would be pleased to send you further information! Please send us a short email to invest@kitekraft.de or call us via +49 89 289 28499.

You have land and you are interested to let us test a kiteKRAFT system on your land or you are interested to become a (pilot) customer? We would love to get in touch with you! Please send us an email to info@kitekraft.de or call us via +49 89 289 28499.

You are a talent and you want to contribute to the kiteKRAFT project? You are welcome to send us your CV and motivational email to work@kitekraft.de.