seminar airborne wind turbines

Airborne Wind Turbines

Presented by Parag Deshpande

IntroductionAn Airborne Wind Turbine (AWT) is a wind turbine with a rotor supported in the air without a tower. It is connected to the ground via tethers. And in some cases, consist of a generator on board, or sometimes on ground.

History of Wind Turbines• The first windmill used for

the production of electricity was built in Scotland in July 1887 by Prof James Blyth of Anderson's College, Glasgow.

• Throughout the 20th century, many people developed small wind stations suitable for farms or residences, and larger utility-scale wind generators

Types of Wind Turbines

1) Horizontal Axis Wind Turbine (HAWT)

2) Vertical Axis Wind Turbine (VAWT)

3) Small Wind turbines

4) Airborne Wind Turbines (AWE)

Horizontal Axis Wind Turbine (HAWT) Vertical Axis Wind

Turbine (VAWT)

Airborne Wind Energy Systems

Ground-Gen systems - In which the conversion of mechanical energy into electrical energy takes place on the ground.

Fly-Gen systems - In which such conversion is done on the aircraft in the air.

Types of Airborne Wind Turbines

Ground-Generator Airborne Wind Energy Systems

The different types Of Ground- Gen AWES –a) Leading Edge Inflatable (LEI)

Kite.b) Supported Leading Edge (SLE)

Kite.c) Foil Kite (design from Skysails)d) Glider (design from Ampyx

Power)e) Swept rigid wing (design from

Enerkite)f) Semi-rigid wing (design from

Kitegen)

Ground-Generator Airborne Wind Energy

Systems - Working

During the generation phase, the aircraft is driven in a way to produce a lift force and consequently a traction (unwinding) force on the ropes that induce the rotation of the electrical generators.

Fly-Gen Airborne Wind Turbine

Different types of Fly-Gen AWES –a) Plane with four turbines, design

by Makani Power.b) Aircraft composed by a frame of

wings and turbines, design by Joby Energy.

c) Toroidal lifting aerostat with a wind turbine in the center, called BAT (Buoyant Airborne Turbine), design by Altaeros Energies.

d) Static suspension quad-rotor in autorotation, design by Sky WindPower

a) Makani PowerThis AWT takes off with the wing plane in a vertical position, driven by propellers thrust. This flight mode is similar to a quad-copter flight and rotors on AWT are used as engines. Once all the rope length has been unwound, the AWT changes flight mode and becoming a tethered flight airplane. In this flight mode a circular flight path is powered by the wind itself and rotors on AWT are used as generators to convert power from the wind. In order to land, a new change of flight mode is performed, and the AWT lands as a quad copter.

b) Joby EnergyThis is similar to Makani, but turbines are installed in the joints of the frame. In Joby's concept, the system is assembled with modular components, constructed from multiple similar frames with turbines. The power generation method and the take-off and landing maneuvers are similar to those of Makani concept.

c) Altaeros EnergiesInstead of using wings lift to fly, they use a ring shaped aerostat with a wind turbine installed in its interior.The whole generator is lighter than the air, so the take-off and landing maneuvers are simplified, and the only remaining issue is the stabilization of the generator in the right position relative to the wind.The aerostat is aerodynamically shaped so that the absolute wind generates lift that helps keeping a high angle of altitude together with the buoyancy force.

d) Sky WindPowerIt is a large quad rotor with at least three identical rotors mounted on an airframe that is linked to a ground station with a rope having inner electrical cables. Take-off and landing maneuvers are similar to those of Makani's and Joby's but generator operation is different. Once it reaches the operational altitude, the frame is inclined at an adjustable controllable angle relative to the wind (up to 50°) and the rotors switch the functioning mode from motor to generator. At this inclined position, the rotors receive from their lower side a projection of the natural wind parallel to their axes. This projection of wind allows autorotation, thus generating both electricity and thrust. Electricity flows to and from the generator through the cable. Sky Windpower tested two prototypes. They claimed that a typical minimum wind speed for autorotation and energy generation is round 10 m/s at an operational altitude.

Wind Power – Locations and Availability

Future Scope

Though many innovative designs and ideas are patented under this airborne wind energy sector, commercialization of the technology ideas has not achieved great success due to various technology and regulatory challenges, space constraints, noise and aesthetics.

Conclusion

High altitude wind energy is currently a very promising resource for the sustainable production of electrical energy. The amount of power and the large availability of winds that blow between 300 and 10000 meters from the ground suggest that Airborne Wind Energy Systems (AWESs) represent an important emerging renewable energy technology.

References• Airborne Wind Turbines – A Technical Report by Scope e-Knowledge Centre Pvt. Ltd. – July 2013• Airborne Wind Energy Systems: A review of the technologies

by - Antonello Cherubini, Andrea Papini, Rocco Vertechy, Marco Fontana PERCRO SEES, TeCIP Institute, Scuola Superiore Sant'Anna, Pisa, Italy

Department of Industrial Engineering, University of Bologna, Italy.• Airborne wind energy: Optimal locations and variability

by Cristina L. Archer, Luca Delle Monache, Daran L. RifeCollege of Earth, Ocean, and Environment, University of Delaware, Newark,DE, US;National Center for Atmospheric Research, Boulder, CO, United StatesGL Garrad Hassan, San Diego, CA, United States

• Wikipedia.org-https://en.wikipedia.org/wiki/Wind_power_in_Indiahttps://en.wikipedia.org/wiki/Airborne_wind_turbine• Open Energy Information –http://en.openei.org/wiki/Wind_energy• Turbines Info-http://www.turbinesinfo.com/types-of-wind-turbines/