05.12.2024, Oberbiberg

Whatch our current Demonstrator fly. As part of the recent "Full-redundancy and Endurance Flight" test campaign we flew into the night for the first time during this live stream, testing our new Anti-Collision-Lights for system visibility. Towards the end of the stream, scenic lightning can be seen in the distance. 00:00:00 Start of live stream 00:04:18 Launch of kite into hover 00:07:53 Transition into eight flight 01:10:52 Transition out of figure eight flight 01:18:06 Landing of kite at ground station 01:23:20 Waiting on flight clearance for next flight 01:44:00 Start of video transmission of flight #2 01:45:01 Launch of kite into hover 01:49:40 Transition into eight flight 01:58:18 Transition out of figure eight flight 02:03:25 Landing of kite at ground station 02:32:56 Start of video transmission of flight #2 02:35:39 Launch of kite into hover 02:39:23 Transition into eight flight 02:46:19 Lightning in the background 02:46:49 Transition out of figure eight flight 02:50:19 Landing of kite at ground station More information regarding our systems can be found on our blog at https://www.kitekraft.de/blog

Whatch our current Demonstrator system perform multiple flights. During the first and second flight a set of flight and lauch parameters were adjusted, which then set the starting configuration for the third flight, which was aimed at flying for multiple hours, into the night. All flights were part f the recent "Full-redundancy and Endurance Flight" test campaign. Unfortunately our camera-drone had transmission difficulties during the first flight, so the footage is a bit jumpy. This could be solved afterwards though. 00:00:00 Start of live stream 00:54:47 Start of video transmission of flight #1 00:58:27 Launch of kite into hover 01:01:52 Transition into eight flight 01:12:10 Transition out of figure eight flight 01:15:18 Landing of kite at ground station 01:23:20 Waiting on flight clearance for next flight 04:06:48 Start of video transmission of flight #2 04:09:54 Launch of kite into hover 04:14:20 End of parameter adjustment 04:18:16 Landing of kite at ground station 04:21:58 Waiting on clearance for next flight 04:47:11 Start of video transmission of flight #3 05:50:42 Launch of kite into hover 05:54:30 Transition into eight flight 06:46:17 Sunset shots 07:59:06 Switch to night vision camera 11:06:00 Transition out of figure eight flight 11:09:39 Landing of kite at ground station More information regarding our systems can be found on our blog at https://www.kitekraft.de/blog

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Kite size: 2.4m wingspan (1:4 scale). Location: Oberbiberg near Munich, Germany Date & time: 24 July 2024, around 4 pm. Wind speed: 1?4m/s from west. (This is below the cut-in wind speed and thus too little for net-positive power generation. A product-version kite would remain on ground and wait for stronger wind.) Name of kite: SN9 "Eser" Blog post with more information coming soon to https://www.kitekraft.de/blog This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

During this flight we tested various controller settings. Blog post with more information coming soon to https://www.kitekraft.de/blog This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

On the left, one of our first prototypes and its attempt to hover. On the right, our current demonstrator with fully functioning ground station, redundancies, and most importantly: All modes of flight. Music credits: Stanley Gurvich - Binary Love (https://artlist.io/song/602/binary-love) This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

On 25.10.2023 Kitekraft successfully conducted its first grid-connected flight. Even though it was not the priority of this test and low wind conditions prevailed, small amounts of energy were generated and fed into the German power grid. Read our blog post about it here: https://www.kitekraft.de/blog/kitekraft-connects-flying-wind-turbine-demonstrator-to-public-grid Kitekraft develops flying wind energy systems. This approach allows to harvest energy from the wind more efficiently compared to conventional wind turbines, because only 10% of the materials are required for the same nominal power. For more information and explanations, please visit https://www.kitekraft.de. Music credits: Yehezkel Raz - Little Eyes - Instrumental Version (https://artlist.io/royalty-free-music/song/little-eyes/81636) This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

Cut version of test flight for different angle of attack controllers (not shown in this video). Complete system flight test, with all modes of operation. Flight conducted completely autonomously, only high-level commands (such as "hover now") were given. 0:00 Intro 0:10 Take-Off 0:38 Reel out Tether 1:04 Rotate Landing Perch to Back 1:27 Trans-In 1:44 Figure Eight Flight 3:03 Trans-Out 3:32 Rotate Landing Perch to Front 4:03 Reel in Tether 4:46 Landing Kite size: 2.4m wingspan (1:4 scale of 100kW product). Location: Oberbiberg near Munich, Germany Date & time: 21 March 2023, around 1 pm. Name of kite: SN8 "Stiffy" (due to upgraded, stiffer tail) Additional chapter information: * Take-Off. In-between flights the kite is parked on the landing perch on the ground station. Once conditions are suitable the kite goes into hover flight, undocking from the ground station. * Reel out Tether. While in hover, the tether is reeled out from the winch on the ground station. The tether attaches the kite to the ground station mechanically and feeds electricity to the kite during hovering. * Rotate Landing Perch to Back. The landing perch is rotate to the backside of the ground station during figure eight flight to free up the space between the ground station and the kite. This way, the tether can move freely. * Trans-In. Once the tether is complete reeled out from the winch, the kite accelerates into figure eight flight mode. * Figure Eight Flight. During figure eight flight, the kite can produce energy, which then reverses the power flow: The onboard propellers (the same that were previously used for hovering) are now used as small wind turbines and produce power aboard the kite. The kite harvests the energy from the wind. During this mode the kite feeds electricity to the ground station and the grid. * Trans-Out. When the flight has to be terminated, e.g., due to a change in weather conditions such as too low wind, the kite transitions out of figure eight flight and back into hover flight. * Rotate Landing Perch to Front. To reel in the tether, the landing perch is rotated to the front again, catching the tether and thus, making sure it is winched correctly. * Reel in Tether. While the kite maintains hover flight, the tether is reeled in, onto the winch. * Landing. Once the tether is reeled in completely and the kite's landing hooks docked to the ground station, the kite ramps down its propellers. It is now securely parked and ready for the next flight. This approach allows us to harvest the energy from the wind more efficiently than conventional wind turbines, because we only use around 10% of the materials. For more information and explanations, please visit https://www.kitekraft.de. Music credits: Liquid Memoirs - Waking up in Limbo (https://artlist.io/song/80916/waking-up-in-limbo) This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

A detailed description of the things happening during take-off, flight, and landing can be found in the description of one of our cut videos, for example this one: https://youtu.be/oVB5skG4I4s Additional information can also be found on our website: www.kitekraft.de This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

Cut version of test flight for different angle of attack controllers (not shown in this video). Complete system flight test, with all modes of operation. Flight conducted completely autonomously, only high-level commands (such as "hover now") were given. 00:00 Take-Off 00:11 Trans-In & Figure Eight Flight 00:55 Trans-Out & Landing Kite size: 2.4m wingspan (1:4 scale of 100kW product). Location: Oberbiberg near Munich, Germany Date & time: 21 March 2023, around 1 pm. Name of kite: SN8 "Stiffy" (due to upgraded, stiffer tail) Additional chapter information: * Take-Off. In-between flights the kite is parked on the landing perch on the ground station. Once conditions are suitable the kite goes into hover flight, undocking from the ground station. While in hover, the tether in reeled out from the winch on the ground station. The tether attaches the kite to the ground station mechanically and feeds electricity to the kite during hovering. * Trans-In & Figure Eight Flight. Once the tether is complete reeled out from the winch, the kite accelerates into figure eight flight mode. During figure eight flight, the kite can produce energy, which then reverses the power flow: The onboard propellers (the same that were previously used for hovering) are now used as small wind turbines and produce power aboard the kite. The kite harvests the energy from the wind. During this mode the kite feeds electricity to the ground station and the grid. * Trans-Out & Landing. When the flight has to be terminated, e.g., due to a change in weather conditions such as too low wind, the kite transitions out of figure eight flight and back into hover flight. Then the tether is reeled in and the kite docks at the ground station. Now it is ready to fly again. This approach allows us to harvest the energy from the wind more efficiently than conventional wind turbines, because we only use around 10% of the materials. For more information and explanations, please visit https://www.kitekraft.de. Music credits: Stanley Gurvich - Binary Love (https://artlist.io/song/602/binary-love) #airbornewindenergy #windenergy #wind #airborne #renewableenergy # renewables #energy #flying #flyingwindturbine This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

Integration Test with new ground station demonstrator: Kite takes off from and lands on ground station with a short figure eight flight in between. 00:00 Intro 00:18 Undock 00:49 Unroll Tether 01:29 Rotate towards Launch Position 01:39 Continue to Unroll Tether 04:08 Rotate Landing Perch away from Tether 04:28 Transition into Figure Eight Flight 04:49 Transition back to Hover 05:09 Hover Down to Reel-In Altitude 05:55 Catch Tether with Landing Perch 06:44 Reel in Tether 08:16 Dock onto Landing Perch 09:57 Power Off Rotors Kite size: 2.4m wingspan (1:4 scale of 100kW product). Location: Otterfing near Munich, Germany Date & time: 07 October 2022, around 2 pm. Name of kite: SN8 "Stiffy" (due to upgraded, stiffer tail) Additional explanation for this test flight: * Full integration test flight with new ground station demonstrator. * Kite now takes off from and lands on the ground station, not touching the ground anymore, similar to the later product. * At first, the kite rests on the ground station. It is hooked to a top landing bar and fixated to the ground station via the tether. * Rotor start, kite starts to lift, and the hooks unhook. * Now, the tether can be unrolled from the winch. During this phase, the landing perch dynamically follows the tether to be able to locate the kite and guide the tether vertically. * Once the full tether is unrolled, the landing perch rotates backwards to free up the tether for the upcoming flight. * The kite starts to transition into figure eight flight (power production mode; during this flight wind was too low to actually produce power). * Only short figure eight flight, as test was intended to show functionality of ground station. * Kite transitions back into hover. * Landing Perch rotates to the front, catching the tether. * Tether is rolled back up onto the winch, again, guided by the sensors on the actively controlled perch. * Tether Hook come in contact with docking beam. * Rotors power off, hooks engage. * Kite ready to fly again. For more information and technology explanations, visit https://www.kitekraft.de/ Music credits: Infraction - No Copyright Music: https://artlist.io/artist/231/sean-williams This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

0:00 - Lift-Off and Hover 0:59 - Trans-In #1 1:09 - Fly 4 Figure-Eights 2:05 - Trans-Out #1 2:15 - Hover 3:00 - Trans-In #2 3:10 - Fly 8 Figure-Eights 5:02 - Trans-Out #2 5:12 - Hover 8:07 - Trans-In #3 8:17 - Fly 16 Figure-Eights 12:07 - Trans-Out #3 12:17 - Hover 14:54 - Trans-In #4 15:04 - Fly 14 Figure-Eights 18:30 - Trans-Out #4 18:40 - Hover 22:00 - Trans-In #5 22:10 - Fly 8 Figure-Eights 24:03 - Trans-Out #5 24:13 - Hover and Touch-Down Kite size: 2.4m wingspan (1:4 scale). Location: Otterfing near Munich, Germany Date & time: 26 January 2021, around 2 pm. Wind speed: 1?4m/s from west. (This is below the cut-in wind speed and thus too little for net-positive power generation. A product-version kite would remain on ground and wait for stronger wind.) Peak positive power: 4.4 kW (at kite in 800V DC tether). Name of kite: SN7 "Lucky" Additional explanation for this test flight: * Technical terms: "Trans-In" is the maneuver to transition from hovering to figure-8 flight, "Trans-Out" is the maneuver to transition from figure-8 flight to hovering, figure-8 flight is the power generation flight phase. * During hovering, the team discussed the kite's test results and the test program. In a product version, the hovering phase would be kept as short as possible. * The flight was controlled autonomously by the kite's control software, apart from receiving high-level commands by the test team such as "launch now" and "land now if possible". * Purpose of test flight: gather data for validation of software updates regarding the control algorithms in all flight maneuvers, test of a sensor switch, and particularly validate stability and repeatability of the trans-in and trans-out maneuvers, which are the most challenging maneuvers the kite has to perform. * More than 2,000 data points are gathered every 25ms (40x per second, 80,000 data points per second) for analysis and optimization. * The flown figure-8 pattern slightly shifts left and right, up and down, and the flight in figure-8 and tether tension is generally not as smooth as it could be, due to not-yet-optimized controller tuning and as a result of conservative safety parameters. * Upcoming implementations include a ground station, with which the kite and tether remain always above the ground. The kite then never starts from or lands on the ground, but instead uses the ground station as docking station/landing pad. For more information and technology explanations, visit https://www.kitekraft.de/ Music credits: Infraction - No Copyright Music: https://youtu.be/JALJa-VVqRg https://youtu.be/DUW4h3UaLdI https://youtu.be/MUalULGdlKo https://youtu.be/2BVUZY1PlG4 https://youtu.be/T6nJHnw76pw https://youtu.be/Loi2SvzreH4 This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

00:00 - Intro. 00:08 - 1. Lift-off at -60° azimuth. 00:21 - 2. Transition into figure-8. 00:28 - 3. Fly figure-8 (power generation). 02:27 - 4. Transition out of figure-8 at -60° azimuth. 02:34 - 5. Hover down (intermediate landing simulation). 03:09 - 6. Transition into figure-8. 03:17 - 7. Fly figure-8 (power generation). 05:20 - 8. Transition out of figure-8 at +60° azimuth. 05:26 - 9. Hover down to 0° azimuth & prepare touch-down. 06:30 - 10. Touch-down. Kite size: 2.4m wingspan (1:4 scale). Location: Otterfing near Munich, Germany Date & time: 13 January 2022, around 3 pm. Wind speed: 1?3m/s from east. (This is below the cut-in wind speed and thus too little for net-positive power generation. A product-version kite would remain on ground and wait for stronger wind.) Peak positive power: 4.2 kW (at kite in 800V DC tether). Name of kite: SN7 "Lucky" Additional explanation for this test flight: * Apart from giving high-level "launch" and "land" commands, the flight was controlled autonomously by the kite's control software. * Purpose of test flight: gather data for validation of software updates regarding the control algorithms in all flight maneuvers. * More than 2,000 data points are gathered every 25ms (40x per second, 80,000 data points per second) for analysis and optimization. * 0° azimuth means downwind direction. * The flown figure-8 pattern slightly shifts left and right as well as up and down due to not-yet-optimized controller tuning and as a result of conservative safety parameters. * Upcoming implementations include a ground station, with which the kite and tether remain always above the ground. The kite then never starts from or lands on the ground, but instead uses the ground station as docking station/landing pad. For more information and technology explanations, visit https://www.kitekraft.de/ Music credits: Infraction - No Copyright Music, https://youtu.be/9tM7xr7qeho and https://youtu.be/8X606VVUa-I This project has received funding from the European Union's Horizon Europe program under Grant Agreement No. 101084216

Snippet from our last wind tunnel test.

See our blog post for details: https://medium.com/kitekraft/tech-deep-dive-how-kitekraft-solves-aerodynamics-e5216135ceaf

Tip: watch in full-screen and maximum resolution. The graphical user interface is just for demoing. Notice the bottom information in the video about the compute time. See our blog post for details: https://medium.com/kitekraft/tech-deep-dive-how-kitekraft-solves-aerodynamics-e5216135ceaf Sign up in our waiting list: https://docs.google.com/forms/d/e/1FAIpQLSfPqblOgcZhke8tTp0Mfr09hQVzyCVlgX6cqeFbOEcXGDxWBw/viewform?usp=sf_link

See more details in our blog post: https://medium.com/kitekraft/kitekraft-succeeds-with-autonomous-all-phase-flight-of-new-kite-demonstrator-f13b12690d55

Assembly and wind tunnel testing of our new 2-element high-lift airfoil on 2.4m wingspan kite. The airfoil achieved a lift coefficient of more than 3.0.

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